Weird gt40 miss/stumbling - please help!
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Engine Repair
Forum Discription: Engine problems and solutions
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=43364
Printed Date: April-28-2024 at 5:59pm
Topic: Weird gt40 miss/stumbling - please help!
Posted By: kylem428
Subject: Weird gt40 miss/stumbling - please help!
Date Posted: August-11-2018 at 1:23am
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So I have an intermittent issue I am experiencing. My 1995 gt40 will miss and stall when warm but when it happens the tach will bounce all over the place despite the engine running at 1k rpms or less. Of note is that I burned an alternator belt recently and replaced it. It has had a smoking belt issue since I’ve owned the boat. Seemingly my tired mando alternator was putting out a steady 13.5 volts after replacing the belt but only around 12 before. In Thinking this through, my stalling problem began after the new belt was put on so on a whim I took it off and the boat ran flawlessly immediately thereafter off the battery. Didn’t skip a beat. I guess I am going to order the 100amp alternator upgrade kit tomorrow with the hope that it was entirely the alternators fault sending a strange voltage or spike to the system causing the ecm to act oddly. Anyone have a similar issue or thoughts on what else I should be checking? I changed the relays just to be safe but Initially I was also thinking possible distributor issues, pip sensor, iac valve, tps, ignition module or ecm, but if removing the belt solved the issue, I think it’s the alternator. Given the wacky tach, I am certain it is electrical based. My hydrophase also registers odd tach readings when the issue presents itself, so it’s not the 6-8 cyl selector on the tach. Also both the Tach and digital rpm read outs function flawlessly when the issue isn’t happening. I’ll try to link to a video I took. I appreciate any thoughts or insight! Thank you, Kyle Kyle |
Replies:
Posted By: kylem428
Date Posted: August-11-2018 at 1:36am
| https://youtube.com/watch?v=8Z3nhjnja4U&feature=youtu.be" rel="nofollow - Gt40 miss |
Posted By: 8122pbrainard
Date Posted: August-11-2018 at 8:58am
Kyle, To me it sounds like the engine is surging rather than a miss?? ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
kylem428 wrote:Posted By: kylem428
Date Posted: August-11-2018 at 10:00am
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Hey Pete it definitely does, but I don’t think I captured the miss great. Sometimes it will stumble at the bottom and almost die. If I try to add throttle when this is happening it will shutter. Kyle |
Posted By: 8122pbrainard
Date Posted: August-11-2018 at 10:51am
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Kyle, I wish I knew more about the GT's. All I can do is suggest going to the GT diagnostic thread in the FAQ's. Also, I know once more members come on, you will get some help. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: Gary S
Date Posted: August-11-2018 at 11:44am
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I'm just guessing and only by the tach jumping could it be the pip sensor? But yet the tach signal comes from the TFI module...... Makes no sense why it clears when the alternator is disconnected. Lewey,Ken ??? ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: gun-driver
Date Posted: August-11-2018 at 12:00pm
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I would think it’s a low voltage issue these motors don’t like low voltage. Watching the video your volt meter is only showing just over 12 volts it should be at 14.5 if the alternator was working correctly. As for the 100 amp alt. I wouldn’t waste the money unless your running a bunch of amps on your stereo, the stock one is more than sufficient. So I would start with the alternator and make you’re getting 14.5 to the battery and also check all the grounds to make sure they are clean and tight and see how she runs after that. |
Posted By: kylem428
Date Posted: August-11-2018 at 12:34pm
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Thank you. I was thinking about this a little further, and doesn’t the tach signal come from the e coil? If so, maybe that’s what is causing my problems which may be voltage related or heat soak related? Going to get my alternator tested this am. I’ll see if I can also pick up a coil. Thanks, Kyle |
Posted By: Gary S
Date Posted: August-11-2018 at 4:26pm
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It’s not with me but I printed up the gt40 manual. It’s much easier to look things up in it than thumbing thru pages here. Tach signal comes from the TFI module not the coil. Go thru the manual before you go changing parts, but because of the engine running fine with the alternator disconnected is suspect so that might be worth checking first ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: kylem428
Date Posted: August-11-2018 at 4:32pm
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Cleaned the IAC valve, put in a new e-coil, and had the alternator tested (allegedly good). Hooked everything back up and same symptoms immediately before engine was at operational temp. Pulled the alternator belt and the boat runs smooth again off the battery. Thinking maybe the voltage regulator in the alternator is shot and shorting out causing a potential voltage draw issue, thus starving the ecm of the needed voltage to run normally. Is this possible? Batteries both show 12.5 v at rest. My battery setup is as follows: 1 interstate mt 34 starting battery (1) and 1 interstate srm 29 deep cycle (2) hooked to an isolator switch. Stereo and ballast always run off of batt 2. I have a yandina c100 combiner relay which auto combines the banks when voltage of system is +13.3v. This is why I was thinking maybe I need a 100amp alt. Upgrade But the 55 has been doing okay despite the issues I am now experiencing. Thanks! |
Posted By: 8122pbrainard
Date Posted: August-11-2018 at 4:50pm
Kyle, Did you go to Autozone for the test? If so, I wouldn't trust anyone except Roger (with the English accent) ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: KENO
Date Posted: August-11-2018 at 9:57pm
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I think you have a bad alternator that's causing too much AC ripple in the alternator output and it's affecting your electronics for the fuel injection/ignition system. If you took it to Pete's favorite place and they slapped it on a machine and said "yup it puts out good voltage" you didn't get a good test. To test the shape of the output wave you need an oscilloscope It'll tell you if one or more of the output diodes is bad. along with a lot of other things. When you're just on the battery there is no ripple, just steady DC voltage (which will drop over time supplying your fuel and ignition systems) but for the short time you were just on the battery it would be pretty much the same voltage. Here's a link to a lot of reading if you happen to be bored. It explains ripple and what a normal waveform looks like and causes and effects of different looking waveforms. https://www.microcharge.de/downloads/Understanding_Generator_Ripple_Waveforms.pdf" rel="nofollow - link |
Posted By: tryathlete
Date Posted: August-12-2018 at 12:26am
| Keno makes a lot of sense. Get that alternator tested on an oscilloscope and report back. Running fine on the battery but wonky on the alternator leads me to agree about the bad diode. I did see you’re trying to get ahold of a used alternator. |
Posted By: kylem428
Date Posted: August-12-2018 at 12:34am
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Hey all. Thanks for the input. It was tested at oreilley and I don’t trust the test very much. The marine alt doesn’t cross with anything in their alt. Test computer so we had to find a similar model 3 wire 55 amp auto alternator of a different make to enter in to the computer to hijack it to run the test. Kyle |
Posted By: gt40KS
Date Posted: August-12-2018 at 1:53am
+1 - My first thought. Haven't heard of "surging" that would cause such wild rpm changes, and so quickly - usually only 200-400 rpm rises/ falls and definitely wouldn't surge to 4000+ let alone peg the tach at 6000 as I saw in the vid - certainly didn't sound like more than a couple hundred rpm's either. You may have more than one issue here too. The alternator spikes would explain the the gauge and very likely explain the uneven idle. But with a new alt, if the surging/ idle rolling continues I'd consider Gary's thought of a loose/ corroded PIP sensor. Also, cleaning the IAC doesn't always do the job and it may need to be replaced. The rolling idle and surging issue that has sometimes plagued the GT40's was also common with Mustangs, Lightnings and some Thunderbirds of the same era and unfortunately after exhaustive research I've found that there are several possible causes - sometimes more than one at a time, compounding the issue. Sure makes it tough to diagnose ... and fix. ------------- JCCI 1995 Ski Nautique GT40 |
Posted By: kylem428
Date Posted: August-12-2018 at 10:25am
| Thanks Joe. You are right in that the tach isn’t actually showing what the boat is doing in terms of rpm. It is running really slow - almost stalling at idle. So much so that limping home the damper plate was clattering because the rpm was so low as to barely engage the transmission. If i gad to guess it was at 500 rpm or less and real rough. |
Posted By: 8122pbrainard
Date Posted: August-12-2018 at 11:07am
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Kyle, I'll throw this to you knowing I'll get the normal criticism from Ken but an alternate to a new alternator is a diode and brush replacement. Depending on the alternator, diodes are available individually or preassembled in their heat sinks. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: KENO
Date Posted: August-12-2018 at 12:17pm
What you sayin' there Pete  Delco parts and kits are available everywhere and they're relatively easy to work on. But as far as a Mando, first you have to find the parts or a kit to do the job |
Posted By: kylem428
Date Posted: August-16-2018 at 3:39am
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So the new alternator failed to solve the issue. At this point I don’t know where to go and am really frustrated. Just to confirm the issue I started the boat with no alternator before doing any work. Started and ran fine. Installed the new alternator, adding a new and beefier ground to the engine block and running the larger + lead to the battery side of the starting solenoid under the ecm, and splicing the green wire in to the old field lead. Go to fire it up and it starts but runs like garbage with the same dancing tach and barely idling. I turn it off. Thinking maybe the culprit is the battery combiner relay, I disconnect it, then crank and no start. Frustrated, I remove the alternator belt and try again. Same result - crank and it won’t fire. Not sure where to turn next other than to start diagnosing a crank and no start issue. Fuel pumps are priming and the ecm/fuel pump relays are brand new. The e-coil is also brand new. Anyone have any good ideas or suggestions? There’s nothing t much summer left... Thanks, Kyle |
Posted By: KENO
Date Posted: August-16-2018 at 8:56am
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Might not help much but since it won't start, do you have spark now? This may be pointing at your distributor like mentioned earlier Maybe whatever component was affected failed with the voltage from the new alternator.; You've replaced a lot of parts, if you decide that the distributor needs work internally you're probably better off on that one just replacing it like Joe (gt40KS) did. Maybe he'll give you a name and part number but other people have used a Dorman FD-14. It sounds like you're going at it methodically . Hopefully not an ECM issue. |
Posted By: KENO
Date Posted: August-16-2018 at 9:38am
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Here's a recent thread Spectra FD14 part number http://www.correctcraftfan.com/forum/forum_posts.asp?TID=43262&KW=&title=gt40-cough-cough-maybe-pull-a-skier" rel="nofollow - link |
Posted By: kylem428
Date Posted: August-16-2018 at 9:54am
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ThanksKeno! So my plan today is to get a fuel pressure gauge I can attach to the rail just to double check I do in fact have fuel pressure when pumps prime and while cranking. Also am going to check for spark during cranking. If I don’t have spark but have 12v on the + side of the coil, I expect this points to a distributor issue? Thank you! Kyle |
Posted By: kylem428
Date Posted: August-16-2018 at 4:30pm
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Good news - I have spark so it’s not the distributor. What I found is that I don’t have any fuel pressure at the rail. Down side is that I have voltage at the carter hp fuel pump plug and independently the fuel pump runs when you put 12v to it on the bench, but isn’t working in the boat. Cleaned contacts and no dice. Low pressure pump does what it is supposed to. I guess I am going to order a new Carter hp pump and lose the 2nd input on the pump coming from the rail tank return and see where that gets me. Anyone have any other ideas? Kyle |
Posted By: Gary S
Date Posted: August-16-2018 at 5:30pm
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On thing you could try is having a helper turn the key while you take a hammer and hit the fuel pump,it could have a bad spot on the commutator and happened to stop on it. Back in my workings days when one of our trucks would get towed in I'd help the mechanic get them started that way. They were always dropped off somewhere in the lot and he had to somehow get them into a bay by himself. I'd start it while he'd beat on the gas tank with a rubber hammer. It seemed they always had a full tank too which he'd have to drain so he could remove it to get to the pump. If it then works order a pump! ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: kylem428
Date Posted: August-16-2018 at 7:34pm
| So I guess I was mistaken about the pressure. Seemingly I have pressure. It just isn’t registering on the gauge that I borrowed. If I turn the key and push the pin in the Schrader valve, fuel squirts out. Next thing I checked is injector plugs for voltage when cranking. Nothin. The needle bounces a little but it’s less than a volt... |
Posted By: kylem428
Date Posted: August-16-2018 at 9:08pm
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So I took out the schrader valve and got the gauge to work. I can build rail pressure to 40psi by cycling the key switch on-off like 5 times. If I crank after that, rail pressure will hold at 40 but if I let off, it immediately drops out and eventually doesn’t have any pressure til I re cycle the key. I’m thinking this points to the high pressure pump, the fuel pressure regulator,or the anti siphon valve. The engine will just hiccup if I keep cranking but won’t really fire. Do the injectors need sustained pressure to be able to fire? Thank you, Kyle |
Posted By: MrMcD
Date Posted: August-16-2018 at 9:33pm
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When I need to check Fuel Pressure I grab my AC gauges, they do dual purpose work in my garage. They connect and work well for checking the Fuel Pressure. Use the Low side gauge as it measures the lower numbers better. A fuel pump issue would show up less with more voltage but yours shows up as your voltage increases. The battery will run the engine but it is limited to 12.6V. The alternator will bump voltage to 13.9V approximately. This is odd to me, I would expect the fuel pumps to work better at 13.9V. Based on your jumping gauges I suspect you have an electrical issue that is affecting more than the gauges. I caution you about bench testing a fuel pump. They are fuel lubricated and I am told running one dry for even 10 seconds will damage the internal bushings the motor runs on. This is the reason you never want to run out of gas with an electric fuel pump. ------------- |
Posted By: Gary S
Date Posted: August-16-2018 at 10:01pm
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I would suggest you download the https://www.skidim.com/SERVICE-MANUAL-GT40/productinfo/L190146/" rel="nofollow - GT40 pdf manual . I downloaded it and went to FedEx/Kinko's and had it printed,bound and made into a manual,was about 55.00 In it are the test procedures, 3H-3 which has you test for fuel pressure leakdown and 3H-15 in which they have you vacuum test and visually inspect the regulator,gaskets and orings. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: kylem428
Date Posted: August-17-2018 at 7:44pm
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Thanks for the link to the manual. I used a few tests from 3h to confirm some things - I borrowed a noid tester and was able to confirm the injectors are firing. On to the fuel pressure test-I when I jumped the fuel pumps I could get to 35# of pressure but it wouldn’t hold. It immediately goes away when I disconnect the jumper wire from ground. As such, per the manual I replaced the fuel pressure regulator , re-test, and same thing. I checked the anti siphon valve on the supply side thinking maybe it is being drawn that way but the valve seems” good, however the pressure in the fuel rail has to be going somewhere. Any thoughts on what to check next? Vacuum system? Does the 35psi from the pumps suggest my hP pump is toast? If you recall, it had a nice squeal when I got the boat but went away once I changed the fuel filter. Kyle |
Posted By: gun-driver
Date Posted: August-17-2018 at 8:56pm
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Try plugging the Tee fitting where the stainless line from the HP connects to the return line and cap the stainless line. Curious to see if your losing pressure through that line. Also when mine was going bad I was showing pressure but it was mostly air in the line, I had to bleed off the air out of the rail to get the motor to run. I used one of these to bleed the rail. https://shop.advanceautoparts.com/p/actron-fuel-pressure-tester-kit-cp7818/9030328-p?c3ch=PLA&c3nid=9030328-P&adtype=pla&gclid=Cj0KCQjw5NnbBRDaARIsAJP-YR9qn7qbUoC-RAmzZ0GXxOXv7j_GhjvGzM44bQca_q6ZZT5gkyqiRd4aAk5aEALw_wcB&gclsrc=aw.ds&dclid=CI7LoZ6X9dwCFdQONwodMjAJnw" rel="nofollow - https://shop.advanceautoparts.com/p/actron-fuel-pressure-tester-kit-cp7818/9030328-p?c3ch=PLA&c3nid=9030328-P&adtype=pla&gclid=Cj0KCQjw5NnbBRDaARIsAJP-YR9qn7qbUoC-RAmzZ0GXxOXv7j_GhjvGzM44bQca_q6ZZT5gkyqiRd4aAk5aEALw_wcB&gclsrc=aw.ds&dclid=CI7LoZ6X9dwCFdQONwodMjAJnw |
Posted By: kylem428
Date Posted: August-18-2018 at 1:04pm
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So I charged the battery yesterday, then disconnected the hp fuel pump line from the rail, attached a hose, and pumped out about a gallon of fuel into a can to make sure things were working. I re-hooked everything up and re did the rail pressure test which I posted about yesterday - same result. I finally got it to run this morning by pulling the neutral switch on the throttle lever and opening up the throttle all the way. It sputtered and then fired up and ran smoothly. This was with the alternator disconnected. I then shut it off, hooked up the alternator and fired it up again. Smooth idle and 14v on the dash gauge. I am now thinking I had a few things going on - low voltage caused by the failing alternator issue from before, and a batch of bad gas or water in the gas, and a flooded engine. I cleared up the water issue by running fuel through the pumps in to the aux tank, then I cleared the flooded engine by starting in neutral WOT, and the voltage was normalized by a charged battery. Before all this the battery was showing 12.5 across the leads but I’m starting to think that maybe the ECM wasn’t getting the voltage it needed to run well and was causing the erratic behavior. Going to fill up with premium and a can of sea foam and use the boat for the day. I appreciate everyone’s thoughts and insight in to what to look for. I’m still stumped on the low fuel pressure at the rail after the key switch is off but I guess if it runs well maybe I won’t worry about it. I suppose I could check the pressure now that the engine has run and provided vacuum to the FP regulator. Maybe that’s the trick in getting it to hold pressure after replacement. Kyle |
Posted By: 8122pbrainard
Date Posted: August-18-2018 at 1:10pm
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Kyle, Make sure you boat today on a lake that does have other traffic or, at the very least bring a paddle with you.  I sure hope what you did solves the problem. Good luck with it. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: KENO
Date Posted: August-18-2018 at 2:08pm
This guy thinks you're gonna be OK Most fuel injection systems have a "clear flood mode" which is doing what you did. Full throttle while cranking cuts the signal to the injectors till the engine is running. Gives lots of air and no gas to clear the flooded condition. Good luck
|
Posted By: kylem428
Date Posted: August-18-2018 at 3:42pm
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Turns out I am still not in the clear. The issue returned as I was just letting the boat run. Upon further inspection, I found that it seemed as though the coil was shorting out with key on engine off at the distributor cap. So I replaced the TFI module thinking that it was leading current to the coil potentially when it shouldn’t be. This did not resolve my issue. With the key on and engine off, sometimes the coil will send a signal to the distributor and it will register on the tack making it look like engine RPMs are bouncing all over the place, and the boat isn’t even running. I’m starting to think that maybe it is the ECM given how intermittent this problem is. This weird interrupted signal will also cause the engine to not run correctly because the voltage from the coil is erratic. Thoughts? Kyle |
Posted By: MrMcD
Date Posted: August-18-2018 at 6:15pm
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It does not sound like the pressure regulator is at fault at all in your boat. Sounds like electronic gremlins. ------------- |
Posted By: KENO
Date Posted: August-18-2018 at 6:24pm
I hate it when Carnac gets it wrong  Have you checked the ground connection from the ECM to be clean and tight? Also maybe unplug and check the cleanliness of the connections in the big connector to the ECM. I figure they're both easy and cost nothing. |
Posted By: kylem428
Date Posted: August-19-2018 at 1:15pm
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Okay new theory - bad distributor. The reason I think this- coil is making a tic tic buzzing noise when the key is on and engine is off. I have a constant 12.5v at the purple wire but the green feed wire voltage coming from the TFI is erratic. The TFI is also new. My understanding is the PIP sensor feeds cam position info to the computer to inform timing. I believe while the pip looks good (not moving) it is providing a faulty signal or shorting out. If I test the blue gray signal wire from the distributor for continuity to ground, there is measurable resistance indicating a partially connected circuit. This is then informing the computer to fire the coil at erratic times causing the rough running condition when I can get it to run. Is there an easier way to test this without a breakout box connected to the ECM or do I need to jump in and replace the distributor? Oreilley has a remanufactured cardone that fits a 92 f250 5.8mpfi which is what I’ve been using as a cross ref. Vehicle for parts. It’s less than $100 but then I introduce error in having to reset the timing. Kyle |
Posted By: tryathlete
Date Posted: August-19-2018 at 2:03pm
| Kyle, a new distributor is pretty cheap, and it sounds like there’s something going on there, and if it were me, I’d do it just to get my boat back up and running. I don’t think you have to worry about timing if you get it close enough (mark position of old distributor and especially rotor). ECM controls timing on the GT40. Others may argue against swapping parts for good reason, but that’s what I would do. |
Posted By: Gary S
Date Posted: August-19-2018 at 3:01pm
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Why in the world would you change the whole distributor unless the distributor has to come out to change that module ? ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: Gary S
Date Posted: August-19-2018 at 3:46pm
http://imgbox.com/2db1Zycp" rel="nofollow"> http://imgbox.com/UMWfkd66" rel="nofollow">  Here are some Ford part numbers which might be some help,you can click on the image to make it larger ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: kylem428
Date Posted: August-19-2018 at 5:05pm
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Thanks Gary. I was under the impression that you had to disassemble the whole distributor to replace the pip sensor/ staror and most opt to replace the whole distributor instead from a cost and effort standpoint. Are you under a different understanding? Kyle |
Posted By: Gary S
Date Posted: August-19-2018 at 5:32pm
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I have not taken one apart yet but in reading it looks like you do have to pull it to change that. Seems crazy. I did find this though- https://www.ford-trucks.com/forums/763884-crankshaft-position-location-95-351-a.html" rel="nofollow - sensor troubles Kind of sounds like your trouble with the erratic tach and all, interesting reading anyway ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: KENO
Date Posted: August-19-2018 at 6:51pm
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if you're gonna replace the PIP sensor , you might as well replace the stator too and if you're gonna replace both, you might as well get one of the rebuilt distributors mentioned earlier in the thread because the only way to do the stator or sensor is by pulling the distributor out, removing the gear and taking the shaft out from the top. Pretty much complete disassembly and reassembly of the distributor. And with the Spectra everything related to the sensors is new, clean and not rusty.And you get a new cap and rotor too. (edit took out my wrong Dorman reference) You'll have to plug the vent in the cap or use the cap you have.. People usually use RTV for that it seems. |
Posted By: kylem428
Date Posted: August-21-2018 at 6:28pm
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So I got the boat to run today and had it running for about a half hour on my lift after replacing the distributor with a spectra fd14 from O’Reillys. The interesting thing is that I still expect that maybe I have a bad ecm. I set the initial timing of the new distributor by unplugging the sprout connector and timing it to 5 btdc. As soon as I did this, I turned off the engine, plugged in the sprout, and it would crank, fire once and die. I then disconnected the sprout, and ran the boat. It ran fine. As it was running, I reconnected the sprout and it would immediately die. Disconnect sprout, and it would run fine timed at 5btdc. After this, I disconnected the battery on a whim while I took a phone call. After my 30 min call, I reconnected the battery and started the boat without the sprout connector. After running for 5 minutes or so I reconnected the sprout connector and it stayed running! Not sure if the computer was reset by the disconnect and had to “re learn” something By running the boat without the sprout for a short period, or if this is a fluke thing that it is now only working for a little while, with my fear being that it will go back to doing as it had. Good to know that at least for now I can disconnect the sprout if it starts running poorly in order to limp my way home at 1000 rpm or less. The downside is I have no way of testing the sprout circuit of the ecm when engine is running poorly without a breakout box. I can only check continuity with ground for a short. Think I need to find an ecm?? Kyle |
Posted By: Gary S
Date Posted: August-21-2018 at 6:52pm
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You have 3 options then if you think it's bad, 1- get yours fixed, 2 use a ecm and a chip like the PN guys figured out or 3- get http://www.correctcraftfan.com/forum/member_profile.asp?PF=16928" rel="nofollow - a hold of Erik and see if he still has the one from the engine he's parting out. https://www.planetnautique.com/vb5/forum/nautique-topics/maintenance-technical-discussion/510361-hope-for-gt40-efi-ecu" rel="nofollow - PN ECM thread Prices on used C1A1 Mustang ecm's have skyrocketed lately, someone must have seen that now there is a use for them,I paid under 90 for one a year ago. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: kylem428
Date Posted: August-21-2018 at 7:08pm
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Yeh Gary I noticed that too while looking. I’ll have to look at the PN thread but if I recall the D1L1 ecm May also be a usable replacement. I’ll have to double check on that. Thanks, Kyle |
Posted By: Gary S
Date Posted: August-21-2018 at 7:42pm
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here are some- https://www.ebay.com/itm/MUSTANG-Computer-PCM-ECM-2-3-LX-Four-4-Cylinder-5-Speed-Manual-91-92-93-LJM/273400288007?_trkparms=aid%3D222007%26algo%3DSIM.MBE%26ao%3D2%26asc%3D53210%26meid%3D165e9b05a50f40078caad4b3fce0bab9%26pid%3D100005%26rk%3D1%26rkt%3D1%26sd%3D263841948048%26itm%3D273400288007&_trksid=p2047675.c100005.m1851" rel="nofollow - 1-C1A1 https://www.ebay.com/itm/MUSTANG-Computer-PCM-ECM-2-3-Four-4-Cylinder-Automatic-Trans-D1L1-91-92-93-KQV/263841948048?hash=item3d6e34a190:g:Tf4AAOSw4NVbW73w" rel="nofollow - 2-D1L1 The D1L1 was thought it might work but not sure if anyone tried it since the C1A1 was so readily available ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: kylem428
Date Posted: August-21-2018 at 8:33pm
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My suspicion was confirmed this afternoon. Coming back from work I ran the boat for another 15 minutes on the boat lift without issue then randomly the erratic behavior came back. The engine quit, I removed the sprout plug and the boat ran fine. I believe the ECM is definitely sending a strange signal to the TFI causing the boat to run poorly. I’ve been studying the GT 40 manual, and I can’t think of a different explanation. That being said, I also bought a code reader off of Amazon so we will see if the ecm has thrown any codes once I receive it sometime today or tomorrow. Kyle |
Posted By: lewy2001
Date Posted: August-21-2018 at 9:32pm
I can verify that the D1L1 works fine. I purchased 2 from an Ebay seller near you Gary (encortempw) they were US $35 each in Nov 2017. Purchased the chip and programmer from Moates. Not as much fun as my Megasquirt but I wanted something almost factory if I ever decide to sell the Sport.  ------------- If you're going through hell, keep going http://www.correctcraftfan.com/diaries/details.asp?ID=2999" rel="nofollow - 89 Ski <a href="http://www.correctcraftfan.com/diaries/details.asp?ID=5685" ta |
Posted By: Gary S
Date Posted: August-21-2018 at 10:43pm
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Good to know Mark. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: kylem428
Date Posted: August-22-2018 at 1:52am
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Got my code reader tonight. No codes with the key on engine off test and no success with getting it to read for the key on engine running test. I had to jumper the single wire to ground for the koeo test so I expect maybe i need to clean the contact for the koer test since that wire needs to be connected to the reader. It’d be nice to know if maybe my oil pressure, knock sensor, or temp sensor are throwing a faulty signal causing the ecm to erratically adjust the timing and being the root cause of my issue but I guess so long as I replaced everything else I’ll find out as soon as I swap the ecm this weekend. Thanks to Erik for having one available and being willing to ship it expeditiously. Hopefully the end of this saga is near, though I have learned a bunch that I otherwise likely wouldn’t have taken the time for. Kyle |
Posted By: KENO
Date Posted: August-22-2018 at 10:45am
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Just a thought or maybe a question You mentioned that you replaced the TFI module What is the part number of the replacement and what color is the casing gray or black? |
Posted By: kylem428
Date Posted: August-22-2018 at 10:51am
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Hey Ken, it is the black module CBE40 and crosses to the Napa TP29 module and the oem ford part number. Kyle |
Posted By: KENO
Date Posted: August-22-2018 at 10:56am
That's a number and color I came up with too. |
Posted By: kylem428
Date Posted: August-22-2018 at 8:07pm
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Thinking I’ve found a smoking gun. When I disconnected the ecm today to check the spout circuit continuity with ground to see if there was a short, pin #1 came out with my harness ecm connector. This is the keep alive power feed which allows the computer to store fault codes in memory. Now there is no surprise as to why I wasn’t getting anything with my code reader. A little water came out of the connector boot when I undid it, and there is visible corrosion on the outside of the ecm box - indicative of the connector and associated contacts having been partially submerged. I would expect that this is not the only circuit to be faulty. When I open up the ecm, everything else looks okay on the circuit board; however, where you could plug in a chip there is a greasy whitish substance which I am assuming is there to prevent the circuits from shorting out. Once I get on a computer I’ll post a few pics. Kyle |
Posted By: kylem428
Date Posted: August-22-2018 at 8:28pm
  
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Posted By: kylem428
Date Posted: August-24-2018 at 3:30pm
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New computer came in today and I installed it over lunch. Boat cranked and started right up, idling steady at 650 rpms. In neutral it also is operating smoothly through higher rpms. Boat idled for approx 20 min and everything seems okay. My only minor concern is that on 2 occasions, after idling for approx 10 min, the engine quit like you turned it off. No sputter or anything. Just stopped with no warning. On both occasions it fired right back up and idled fine, so not sure what this was about. I will be water testing more this weekend so hopefully everything stays in order. Kyle |
Posted By: tryathlete
Date Posted: August-24-2018 at 3:37pm
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Kyle, I am curious if you made sure the multipin connector is in good shape. I think you saw a lot of corrosion in there. What’s your confidence that connector is doing it’s job? The SS sure is going to be good for the long haul once you get this settled. I spent a lot of time chasing my ignition switch a few years back. It almost made no sense to replace it, but when I decided to do so, the issues went away. |
Posted By: kylem428
Date Posted: August-24-2018 at 4:04pm
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In looking at the harness connector and the pins on the ecm- new and old, they looked good but maybe I should disassemble, spray contact cleaner on the harness plug making sure all the contacts get a dose, and re-assemble with dialectic grease to ensure solid contact. Any reason not to use the grease and just clean the contacts? Kyle |
Posted By: Gary S
Date Posted: August-24-2018 at 4:08pm
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What tune is the new ECM ? 290 or 300? Just curious ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: kylem428
Date Posted: August-24-2018 at 4:21pm
| It’s the 300m tune |
Posted By: kylem428
Date Posted: August-25-2018 at 9:05pm
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Ran the boat for 40 minutes today. on 4 or 5 occasions during this time I had an engine stumble while on plane and the engine either died or almost died. I went to neutral, the rpm either stabilized or I restarted the engine. I was thinking in my head that my fuel pumps were probably going bad so I headed back to the dock. On a whim I went to town and picked up some contact cleaner, and the returned and disconnected the battery and ecm in order to clean the contacts. I Sprayed contact cleaner on the ecm pins and the harness connector, let them dry and then assembled. I also unbolted the ground connections from the bell housing and doused them in contact cleaner, and re-assembled. After that we ran the boat for about 1.2 hours. Right away the boat stumbled once and caught itself at 1krpm but after that it didn’t miss a beat, I’m back on to thinking the stumble/die issue has been due to a bout of bad gas or water in The gas that worked its way through the system. I’ve been having similar low power/ stalling issues on a jet ski that I have which I filled up with a Jerry can that was in my garage for 2 weeks during the hot and humid part of summer. I think I put 12 gallons of this same gas in my boat at the time as well. Hopefully tomorrow is another good day. Kyle |
Posted By: MrMcD
Date Posted: August-26-2018 at 2:41am
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Fuel does not age well anymore. If it is 6 mos old or more get rid of it. If you go in lawn mower shops they will have a sign up warning owners of using bad gas. Maybe your gas was not that old and maybe it is just water in your fuel. I had a BMW once that had water in the gas tank after a major body repair. I am sure they left it open while outside in the rain. We finally cleaned it out using alcohol. I don't remember what kind we used but I was told the alcohol would disperse the water off the bottom of the tank and help it burn as it traveled through your fuel system. It worked for my car. With a flashlight you should be able to see in your tank. Water is visible floating around like a bubble in the bottom of the tank. ------------- |
Posted By: 8122pbrainard
Date Posted: August-26-2018 at 7:15am
Mark, https://www.goldeagle.com/product/heet-gas-line-antifreeze-water-remover/" rel="nofollow - Heet in California? ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: MrMcD
Date Posted: August-26-2018 at 3:17pm
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I think I used rubbing alcohol purchased at the local pharmacy. I might have been listening to Hotel California! Saw the Eagles live several times back in the late 70's. On one ticket at the Oakland Colosseum we saw, America, The Eagles, The Doobie Brothers and closed out with Chicago. Great Show. ------------- |