Misfireing 1994 SN196
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Boat Maintenance
Forum Discription: Discuss maintenance of your Correct Craft
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=30329
Printed Date: November-18-2024 at 4:45am
Topic: Misfireing 1994 SN196
Posted By: Fly100
Subject: Misfireing 1994 SN196
Date Posted: June-18-2013 at 7:14am
More woes and the love of owning a boat  ....Misfire now.So runs fine until its warm, stop for a few mins and then it starts playing up. Am guessing the its getting heat soaked under the hood. New plugs so far, cap and rotor arm are ok. Its got the protec conversion to Mallory on it, approx. 4 years old everything was new then ( leads etc etc.). Its not fuel sure its some sort of heat failure. Coil ? its warm but not really hot ? Once again any thoughts ?? Cheers FLY |
Replies:
Posted By: SNobsessed
Date Posted: June-18-2013 at 9:10am
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Sounds like coil. What kind is it? ------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |
Posted By: Bri892001
Date Posted: June-18-2013 at 11:40am
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I agree with Chris that the coil is one likely suspect. A little more info on the exact circumstances would be helpful though. Like, if you kept driving the boat without shutting down, would you ever have a problem? I ask, because a carb that's dripping fuel out of the primaries when the motor is shut down can make restarts a little tough as well. |
Posted By: Fly100
Date Posted: June-18-2013 at 6:04pm
Coil is the one that came with the kit from Skidim (usa) Its not the carb as a new one was fitted (old one was failing to hold mixture right) It misses up to about 3k then as boat starts to plane and the load comes off she runs clear. |
Bri892001 wrote:Posted By: Bri892001
Date Posted: June-18-2013 at 6:33pm
| I wouldn't rule out the coil just yet even though it's fairly new. If it's oil filled and laying on it's side, it could be the problem. |
Posted By: Fly100
Date Posted: June-18-2013 at 6:48pm
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Correct, it is on its side ! is that an issue ? If I put it vertical will that help or is it too late now ( damage already done??). FLY |
Posted By: Foot_Fungus
Date Posted: June-18-2013 at 7:32pm
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If its on its side I'd say that's the problem. Side mounting those coils is just bad mechanics. More than likely the damage is already done as the fluid has probably leaked out over time. Luckily coils are cheap. Generally speaking the coils operate fine cold, but as soon as they heat up they don't have enough fluid in them and begin to act up. classic symptoms of when one has cracked and/or leaked. ------------- '94SN Restoration underway... |
Posted By: backfoot100
Date Posted: June-19-2013 at 10:45am
Agree with Brian. Are you having misfiring or hard warm starts after shutdown. Two completely different scenarios with completely different troubleshooting. ------------- When people run down to the lake to see what's making that noise, you've succeeded. Eddie |
Posted By: Fly100
Date Posted: June-19-2013 at 10:48am
Starts fine just a misfire when hot ( worse after it had a few mins standing after a run (make me think of heat soak)) FLY |
Posted By: backfoot100
Date Posted: June-19-2013 at 10:59am
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Then I agree with everybody else. Try a new coil. They aren't that expensive and very easy to confirm the problem. Replace when it starts to act up and you know immediately. Having them lay on the side is not good for them if they're oil filled. Get an epoxy filled one and you can mount it anyway you feel like however, they are a bit more expensive. ------------- When people run down to the lake to see what's making that noise, you've succeeded. Eddie |
Posted By: TRBenj
Date Posted: June-19-2013 at 11:39am
This is not the proper way to diagnose a problem. Ive seen plenty of new and freshly rebuilt carbs drip after shut down. Far and away the most common "hot starting issue". Take a look down the throat before you spend a dime on any parts.
I have seen faulty ignition components cause issues before, but very rarely will an ignition issue cause the engine to start hard and then run better at higher RPM. While a few people in the know have said that some of the early Multiport EFI (GT40) engines can heat soak under the right conditions, I have never seen it with a carb. The described symptoms are nearly always a post shut-down fuel drip. Let me guess- if you shut down and restart right away, its not an issue. If you give it a minute or 2, then its problematic. Leave it for an hour or more (or overnight) and its fine. Scenario #1 happens because the drip hasnt had enough time to flood the engine. Scenario #2 happens when it does. Scenario #3 is when the fuel has enough time to evaporate off the intake manifold before you attempt to restart. Next time you have an issue and are too lazy to pull off the flame arrestor, try opening the throttle all the way. Do not pump it, just open it. This will introduce more air and allow it to start. Keep the RPM's high (1500-2000) for a second or 2 and it will clear out the extra fuel that dripped down post shut off. ------------- |
Posted By: Fly100
Date Posted: June-19-2013 at 6:21pm
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New coil will be here in the morning, as will a large storm !!! Will report back for other users info. Thanks fellas, FLY |
Posted By: wake_2001
Date Posted: June-27-2013 at 12:44am
| Any news? I'm having the exact same problem you describe. Runs PERFECT until it's hot then coming out of the hole it will sputter/miss until the rpm's get up. Hard to start too. I've tried the wide open throttle with no luck as well. My only problem with getting a new coil is I'm not sure what EI conversion kit I have. I'm learning as I go. Pretty sure I don't have an external resistor though. |
Posted By: 89Martinique
Date Posted: June-27-2013 at 1:29am
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Also try putting your old cap back on. Our friend did a regular tune up on his MC. Ran out of fuel and after that it ran like crap. Turns out the new cap had faulty insulation and was arching over. Put the old one on and ran great. Now, why did running out of fuel cause it to suddenly ran bad? No idea... ------------- Current Boats: 1992 Supra Comp-TS6M PCM 351w HO Pro Boss Pro-Tec Ignition - Full Composite (no wood stingers!) 1989 (3rd Gen) Correct Craft Martinique B/R PCM 351w Power Plus 1984 E-Scow Keuka Lake, |
Posted By: Fly100
Date Posted: June-27-2013 at 5:58am
Guys, Sorry for the dealy with a mixture of crap weather and me having 'the man flu'. However im pleased to report last night I got a new coil on it and now all seems to be well. No misfires or alike. Just for Ref what is the max RPM of the 351 Windsor ( SN 196 1994 Red rocker covers) Im running LPG and you can easily over fuel them and makeing them rev to stupid revs. |
Posted By: wake_2001
Date Posted: June-27-2013 at 12:26pm
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No worries. I'm sure we all have good intentions of using our boats more than we do. And that is great new for the both of us. I've just got to figure out which coil I need... or will any coil work for any EI conversion? Did you go epoxy filled or stick with oil? And I'm no help on the RPM's. I'll leave that to the experts here. |
Posted By: 89Martinique
Date Posted: June-27-2013 at 12:28pm
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Is it, or was it a GT40P HO? If so, I would make WOT around 4,600 rpm. ------------- Current Boats: 1992 Supra Comp-TS6M PCM 351w HO Pro Boss Pro-Tec Ignition - Full Composite (no wood stingers!) 1989 (3rd Gen) Correct Craft Martinique B/R PCM 351w Power Plus 1984 E-Scow Keuka Lake, |
Posted By: Fly100
Date Posted: June-27-2013 at 12:52pm
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I replaced the coil with a good quality oil filled one ( my boat had the ballast resistor) Im going to try and relocate back towards the gearbox and into a more upright position. As for the motor rpm, how do I ID it ?? |
Posted By: 89Martinique
Date Posted: June-27-2013 at 11:52pm
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Post some pics. Did it used to be EFI? ------------- Current Boats: 1992 Supra Comp-TS6M PCM 351w HO Pro Boss Pro-Tec Ignition - Full Composite (no wood stingers!) 1989 (3rd Gen) Correct Craft Martinique B/R PCM 351w Power Plus 1984 E-Scow Keuka Lake, |
Posted By: Fly100
Date Posted: June-28-2013 at 6:00am
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%20" rel="nofollow - http://boatsaleads.com/wp-content/uploads/1994-correct-craft-ski-nautique--18.jpg Thats the same as mine. |
Posted By: TRBenj
Date Posted: June-28-2013 at 11:08am
There is no such thing as a "GT40p HO" that came from any of the marinizers. 4600 is also the wrong RPM to be targeting for a boat equipped with GT40p heads. ------------- |
Posted By: 89Martinique
Date Posted: June-28-2013 at 12:27pm
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Ok. They call it a GT40 EFI dont they? Mine should have GT40 heads but its labeled HO. Then what is the correct WOT? My PCM stat sheet states 4600 RPM WOT Ford 351W HO ------------- Current Boats: 1992 Supra Comp-TS6M PCM 351w HO Pro Boss Pro-Tec Ignition - Full Composite (no wood stingers!) 1989 (3rd Gen) Correct Craft Martinique B/R PCM 351w Power Plus 1984 E-Scow Keuka Lake, |
Posted By: TRBenj
Date Posted: June-28-2013 at 12:51pm
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The PCM "GT40" was the multiport EFI version of the 351w HO, it came out in 1995. The carb and TBI versions of the HO were called "Pro Boss" (the GT40 also got the Pro Boss label but generally wasnt referred to as such). All HO 351w's came with cast iron Ford GT40 heads. GT40 and GT40P heads share some similar design elements since they are both factory cast iron heads, but they are NOT the same. While they are a popular aftermarket upgrade for people like us, they were never offered by PCM or any other marinizer as a factory option, as far as I am aware. Both GT40 and GT40p headed 351w's tend to run best when propped to turn in the 4800-5000rpm range. ------------- |
Posted By: wake_2001
Date Posted: June-28-2013 at 4:16pm
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Well, I figured out that I have a Prestolite EI conversion. Ordered the MSD Blaster High Vib. epoxy filled coil. Also traced some wires to where it looks like a ballast resistor was deleted. Coil should be in Monday and I'll have the boat out Thursday. Hope to have some positive feedback as well. I'm thinking my current coil (about two years old) should have a resistor. My problem has existed for about that time, but it's been manageable. What would not having a resistor on a coil that should have one do? I'm guessing fry the coil and cause the symtoms I'm experiencing, but anything else? It runs fine until hot. |
Posted By: SNobsessed
Date Posted: June-28-2013 at 5:07pm
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Only the coil would be affected by the higher current (no ballast resistor). BTW, an old ignition guru pointed out to me that the Presotlite EI system does not take a ballast resister. Maybe it is coil specific, dunno. I have the prestolite EI + same coil you are getting, no ballast resistor, works great. ------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |
Posted By: wake_2001
Date Posted: June-28-2013 at 5:26pm
| Thanks. I think it was one of your old posts that lead me to that coil. I'm hoping this solves my issues and that it's just the oil filled coil that can't handle the heat. (literally) |
Posted By: Fly100
Date Posted: July-01-2013 at 12:28pm
I can report back after a full tank of fuel yesterday ( and some aching arms and a very sunburnt face) that the new coil seems to have fixed my misfire!! Happy days. Thanks for the help guys.
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Posted By: wake_2001
Date Posted: July-09-2013 at 7:35pm
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Congrats, Fly100. I'm happy to report the same. After putting 17 hours on the boat it is running better than it ever has. Didn't have a single issue. Started perfectly when hot or cold and didn't miss a beat out of the hole or idling for extended periods. Prestolite EI conversion with the MSD High Vibration coil. No resistor. I recommend this coil to anyone who is having hot start issues or whose engine is "missing" or "bogging" when hot. Best $55 I've spent in a while. Apologies if I seem over excited about this, but I've been trying to figure out this problem for over a year. Even had a couple different mechanics take a stab at it to no avail. I owe you guys a big THANKS! This site is great, but we already knew that. 
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