97 Sport runs awhile then dies
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=51740
Printed Date: November-21-2024 at 12:02pm
Topic: 97 Sport runs awhile then dies
Posted By: TG3
Subject: 97 Sport runs awhile then dies
Date Posted: August-19-2024 at 12:23pm
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I’m having some trouble with my ’97 Sport Nautique. PCM GT-40 engine. I replaced the fuel filter when I got it out of storage as I usually do, and this year I gave it new plugs, wires, cap and rotor. First time out I noticed my fuel consumption has increased. On our 4th outing this summer, we ran the boat off and on all day. On our last run of the evening, I left the dock, gave it moderate throttle to get to about 20 miles an hour and it died. No drama, no coughing, just stopped. It would not restart. It would turn over fine, sometimes “catch” like it was starting but as soon as i released the key and the starter quit turning it would die. I got towed to the dock where it sat until the next day, roughly 24 hours. I was going to be towed to the marina by a friend, but I tried to start it before we left, it started fine. So we made it to the marina under our own power with no problems. I took it in to the our local Nautique dealer as we were about to leave town for vacation. 4 weeks later they got to it and the first thing they found was a faulty starter, so they replaced that along with the battery cables/ends. After that they ran it and tried to diagnose it but it ran “like a top, nothing we can find wrong with it at this time.” So this past Saturday we took it out for the day. It was a bit more difficult to start when I first put it in the water, but then it ran fine. We tubed and skied in several sessions that day, with an hour or so break between each session. with the exception of one time early in the day where it took a few turns of the key to start, it cranked fine and ran great (though still burning more fuel than last summer). Third session out, idled for a few minutes while a kid got situated on the kneeboard, and it died. No warning, just died and would not restart. We got towed to the dock where it sat for a few hours, then I tried starting again, no luck, so towed back to the marina. The next evening, so roughly 24 hours after it died, I hooked up the water hose and it fired right up and ran smoothly. It seems that whatever the problem is, either time or heat is causing the shut down. I have some videos of trying to start it right after it died, several hours later when I tried again, and a video of when it cranked right up after 24 hours. I can post these if they would be helpful. Any suggestions would be helpful, I’m am hoping I can get it fixed myself this time and not have to wait in line another month at the dealership. ------------- 1997 Air/Sport Nautique |
Replies:
Posted By: MurphyCO
Date Posted: August-19-2024 at 3:50pm
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I had the very same issue a couple years back. 99 Air GT40. Culprit was the low-pressure fuel pump. Replaced and absolutely never had an issue again. Hope that helps. GR
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Posted By: KENO
Date Posted: August-19-2024 at 8:04pm
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I suppose you have some choices here with the LP fuel pump being a likely suspect If you have a spark checker and a fuel pressure gauge, using them when it quits will tell you a lot. Check for spark right after it quits. Things like ignition modules can heat up, quit and after they cool down, start working again. Can you hear the fuel pump(s) prime for a couple of seconds when you turn the key after it quits or do you hear nothing from the fuel pumps? If they run, your fuel pressure with the key in Run and the engine OFF should be 39 plus or minus 3 psi and if it's running at idle speed it should be 31 plus or minus 3 psi. The pump could be drawing too much current and tripping the 15 amp breaker on the back of the engine, then when the breaker cools off and resets itself, you'll have power to the pumps again. It could also be a bad fuel pump relay or ECM relay, but they usually either work or don't work. It wouldn't hurt to replace both of them at the same time though with new ones and check the connections at the sockets they plug into. If you have one bad one, it does you no good to swap it with the other good one You need 2 good relays for the fuel pump to run. Both the ECM and the fuel pump relays need to be good. If you decide to replace the pump, PCM's part number for the pump is RA0800018. A lot of places sell an "equivalent' pump covering a huge range of prices. A Carter P4389 0r P4594 are a couple of those equivalents Here's a link to an old thread with some pump info http://www.correctcraftfan.com/forum/forum_posts.asp?TID=51267&title=2000-gt40-low-pressure-fuel-pumps" rel="nofollow - link Just like your shaft thread, this might present you with multiple "opportunities"
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Posted By: TG3
Date Posted: August-20-2024 at 4:20pm
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These are good suggestions, I don't want to waste money. I will get a spark checker and a fuel pressure gauge and head to the lake for some trouble shooting. We are preparing to take our daughter off to college in a few weeks so as soon as we get that done I will trouble shoot and report back. Thank you for helping with where to start! ------------- 1997 Air/Sport Nautique |
Posted By: TG3
Date Posted: September-06-2024 at 8:42am
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I have the spark checker and a fuel pressure gauge kit on hand. A couple questions: 1. Where do i connect the gauge to test pressures? Are there more multiple places to connect? 2. Weather isn’t looking great for being on the water in a stalled boat and doing diagnostics. Do you think i can get it hot enough running it in my driveway hooked to the water hose to get it to die? Or do you think it needs actual load to make it quit? ------------- 1997 Air/Sport Nautique |
Posted By: TRBenj
Date Posted: September-06-2024 at 10:34am
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If your FCC doesn’t have a valve on the top, check the front end of the stbd fuel rail. In addition to fuel pressures (proper ranges are cited somewhere on this site but I recall 31ish at idle and 38ish at wot or engine off after key cycling), checking the fuel level in the FCC immediately after it acts up may prove helpful. I just replaced a marginal LPP that left the canister very low after running hard. |
Posted By: TG3
Date Posted: September-06-2024 at 5:31pm
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Thanks, I'll look in those places. That's a good tip about the fuel level in the FCC. Anybody have any thoughts on if running it in the driveway will get it hot enough to make it quit? It would be a whole lot easier to let it run at 2500 rpm or something for awhile in the driveway then have to be stalled on the lake diagnosing and then have get towed in! Plus my shop full of tools is at the end of my drive, not out at the lake..... ------------- 1997 Air/Sport Nautique |
Posted By: KENO
Date Posted: September-06-2024 at 7:43pm
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The thread in the link below has a picture of the test connection on the front of the fuel rail with a gauge hooked up. The one on top of the FCC will be obvious, sticking straight up if you have one. They look like the valve stem on a tire. It has some other pictures of stuff too http://www.correctcraftfan.com/forum/forum_posts.asp?TID=49818&title=gt40-wont-start-after-tune-up" rel="nofollow - link If it's a fuel supply issue, then running it at no load at 2500 rpm in neutral probably won't help you much at all. 2500 rpm loaded uses a lot more fuel than running it in neutral with no load. If it's something electrical heating up, you might find it though. Can't hurt to try it though and see if you figure anything out PS..........Hope your water supply is good |
Posted By: TG3
Date Posted: September-06-2024 at 10:50pm
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Thanks for the link, I saw the picture of the valve on the end of the fuel rail. I will see if I also have the one on the FCC. That makes sense about the loading. I have some thinks I need to do in the shop tomorrow, I may just let it run awhile and check the fuel pressure periodically to see if I notice any change, even if it doesn't quit running. I will report back. ------------- 1997 Air/Sport Nautique |
Posted By: TG3
Date Posted: September-15-2024 at 3:22pm
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Still have not been able to go to the lake, however, I hooked up the water hose in the driveway and checked the fuel pressure while it was cold. I had 36 pounds key on, engine off measured at the fuel rail valve. Engine cranked instantly like I’m used to, and I measured 32 pounds at idle. It appears that when it’s cold, I have proper fuel pressure. Next step will be a lake run to get it good and hot and see if it will die again and diagnose with fuel pressure gauge and spark checker. Also, as suggested above, I replaced the fuel pressure and ECM relays with genuine Hella relays from nautiqueparts.com just to be sure. The old ones looked perfect inside the connection. Terminals were clean and bright, no signs of heat or burning. As a sidenote, the new Hella relays are made in China, whereas the originals were made in the USA! ------------- 1997 Air/Sport Nautique |
Posted By: TG3
Date Posted: September-21-2024 at 10:37pm
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We went to the lake today and tried to simulate the same conditions as the previous times. We ran out of daylight before i could get it to die and not restart. However, at one point we were running at approximately 30 mph and it started losing power and then running ok, then losing power again. I pulled it back to neutral and it died. Thinking that his was typical, i pulled out my spark checker first, attached it and then cranked. The boat started right back up, spark checker showed good (of course it would it was running again). It ran fine the rest of the evening, so we headed back to the marina. Once on the trailer, i hooked up the fuel pressure gauge, just to see. Engine temp showed 160 degrees on the gauge. Fuel pressure at Key On Engine Off showed 20 Ibs. I could hear the high pressure pump when the key came on. It cranked right up and the pressure gauge showed 30 lbs at idle. Based on what happened today, and fuel pressure readings, sounds like a fuel problem to me. What do you guys think? ------------- 1997 Air/Sport Nautique |
Posted By: KENO
Date Posted: September-23-2024 at 7:54am
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I think you need to drive around with the fuel pressure gauge hooked up and readable (engine cover up or extended hose on gauge) and watch the fuel pressure. It should be about 31 ish at idle and 39 ish at full throttle and somewhere between those numbers at cruising speeds. (The ish is for plus or minus 3) You might have something like 34 or 35 at part throttle cruising speed. Key On Engine Off should be 39 ish
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Posted By: TG3
Date Posted: September-23-2024 at 11:26am
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Ok, we will give that a try this weekend. Just curious, if indeed there is a fuel pressure problem, how do you determine if it is the low pressure pump or the high pressure pump? ------------- 1997 Air/Sport Nautique |
Posted By: TG3
Date Posted: October-20-2024 at 10:36pm
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I ran the boat for about an hour this weekend. Weather here was about 75 degrees, the water was cold and the engine temps barely reached 120 degrees. I had the exact right fuel pressures as Keno listed in previous posts. I didn't have enough time to run the boat until it died, nor am I sure that it would have since it was so cool (at least if my issue is heat related). I am out of time and season to test any more until spring. I'll try again in the spring and test it after it dies. Thanks for all the help. ------------- 1997 Air/Sport Nautique |