97sport nautique intermittent start/run
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=49029
Printed Date: October-05-2024 at 10:34pm
Topic: 97sport nautique intermittent start/run
Posted By: Kbehnke
Subject: 97sport nautique intermittent start/run
Date Posted: August-07-2020 at 12:10am
|
Hey everyone I’ve been having some wierd issue with my new to me 97 sport nautique. Boat has ran fine for the few trips I took it out on but on our last trip was having some issues . It’s a PCM GT40 EfI . When I go to start it seems to have a weak crank but if I hold open the throttle it will slowly come around and run. When it runs it will be intermittent with idle and run WOT no problem . Coming back down to idle it seems to idle rough and eventually die out. Sometime it will start back up fine and others I need to open the thriottle at motor . Things I’ve done already Changed out both hella relays (fuel pump and EEC?) Cleaned cap Replaced inline 50amp fuse and fuse holder at battery with aftermarket inline fuse Checked for loose ground and connections. Fuel pressure checks out at 39psi with key on not running Any suggestions would be greatly appreciated and very excited this website is back up Thanks! ------------- 97 Sport Nautique |
Replies:
Posted By: slmskrs
Date Posted: August-07-2020 at 2:18am
|
When you say weak crank, you mean slow? I'm going to initially assume all of your issues are electrical in nature: * Have you checked voltage at the battery and at the starter (I assume so since you checked ground)? * Have you checked the status of the battery? * What about alternator output? If it runs fine at higher RPMs but not well at idle, it could be low voltage * Try jumping a known good battery directly to the starter with jumper cables and see if it turns over faster. If still slow, maybe a dying starter? Now, assuming the starter is one issue and one of the above solves for that, but you still have the poor idle/stalling, I'd probable check the ICV (idle control valve). Is the engine actually loping before it stalls? Or just really rough/slow? the GT40 is known for loping when very cold as well as when very hot (such as when you've been running it hard on a hot day, and then it sits for 30 minutes or more steaming in the bilge). If you have loping, there are a few tests I've done to isolate it, and it ends up being the ICV. You should also check the fuel pressure while running at idle and with load. ------------- Gordon '97 Ski Nautique, GT40 |
Posted By: Kbehnke
Date Posted: August-07-2020 at 6:56pm
|
Ok will try these ideas thank you can’t seem to find part number for idle control does anyone got one? Thank you ------------- 97 Sport Nautique |
Posted By: Gary S
Date Posted: August-07-2020 at 7:42pm
|
The Ford part number for the throttle air bypass is E9SZ-9F715-F If you want to try something get a Felpro gasket # 71216 and remove the valve.In it's mounting block there is a "screen" that can get clogged up. Remove it and soak it in carb cleaner and see if that helps ------------- 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: slmskrs
Date Posted: August-09-2020 at 1:47am
One other thing you can do once you remove the valve is to start the engine. It should run around 1200 rpm (if I remember correctly when I tested mine and eventually replaced it) because air is going through the bypass hole. Is it running smooth then? If so, you can slowly block off the bypass hole to lower the RPMs closer to 600-700 and see if it starts running rough. If it starts to run rough / die at 700 RPM without the valve in place, then it's something else. If it runs smooth and doesn't die (unless you plug the hole too much), then it could be the idle valve. ------------- Gordon '97 Ski Nautique, GT40 |
Gary S wrote: