cuts out after a minute
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=50621
Printed Date: March-11-2025 at 1:05am
Topic: cuts out after a minute
Posted By: BaccoBouncer
Subject: cuts out after a minute
Date Posted: May-15-2022 at 8:53pm
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First start up of the season. It's a '97 GM PCM that used to be EFI but now has a Holley 4 barrell on it. Holley was put on about three years ago. I winter store it with Stabil in the fuel. So..... it starts right up but then after about a minute it seems to starve of fuel and stall. It stalls even if I just let it idle or if I run it at part throttle. The timing differs, sometimes one minute sometimes three minutes. Spark plugs look like it is running lean, grey & dry. I have wrapped on the bowl with a rubber mallett (stuck float fix), but didnt seem to do it. Ideas? Thanks ------------- '97 21' Sport Nautique |
Replies:
Posted By: MrMcD
Date Posted: May-16-2022 at 3:07am
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There is a fuel check valve on the gas tank, they can plug up or stick causing no fuel to flow. Remove your fuel line from the carburetor and direct the gas line into a gas can. This boat was converted from Fuel Injection, are you still running the electric pump? . An electric fuel pump should pump right away with your key on. Sometimes when going bad they heat up and lock pumping no fuel. More details needed to find your solution. If your pump is set up properly it will turn on your pump for 2-3 seconds when you turn the key and then shut down if it does not detect Oil pressure or more modern systems look for a crank sensor signal. It could be your pump is not getting the signal that your engine is running so it shuts off the pump. That could be a bad sensor. Does it shut off like someone turned the key off or just lose power and die with a little stumble as it runs out of gas. ------------- |
Posted By: KENO
Date Posted: May-16-2022 at 6:40am
This kinda sorta sounds somewhat like Deja Vu all over again  Here's a link to last year's thread http://www.correctcraftfan.com/forum/forum_posts.asp?TID=49820&KW=&title=starts-and-then-cuts-out" rel="nofollow - link It sounds like a fuel issue this year too. I'd probably hook a temporary tank to the fuel pump and start and run the engine and see if the problem is still there or if it runs OK on the temporary tank. Make sure the temporary tank is vented so you don't draw a vacuum that the fuel pump can't overcome. That way you'll narrow it down to a problem with the fuel pump/carburetor or something upstream of the pump like the anti siphon valve at the tank, the fuel pickup tube in the tank a filter in the suction line, collapsed suction line etc. Here's a picture of one hooked to the suction filter just before the pump. It was a new filter and the temp tank narrowed down the problem to the tank side of things.  |
Posted By: BaccoBouncer
Date Posted: May-16-2022 at 9:18am
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ok, I'll start back at the tank and begin bypassing with fuel. It is a mechanical pump, not electric. three years old. Where is that check valve on the tank? ------------- '97 21' Sport Nautique |
Posted By: KENO
Date Posted: May-16-2022 at 9:59am
The Anti siphon valve is on top of the tank, looks like a barbed hose fitting from the outside, but has a little spring loaded ball valve inside. Here are a couple of representative pictures First one is a valve and the suction tube it screws in to. You should also pull the whole tube for inspection or at the very least blow some air backwards through it, On your plastic tank, it just screws into the tank. Some suction tubes have a screen at the bottom that can get plugged/restricted with junk...........some don't and the junk ends up in the anti siphon valve inlet  Second picture is a 97 Sport gas tank from somewhere on the internet, Fuel line with the red band around it is clamped to the Anti Siphon valve  |
BaccoBouncer wrote:Posted By: BaccoBouncer
Date Posted: May-16-2022 at 11:36am
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So one diagnosis possibility is detach line here and submerge in 5 gal gas tank? ------------- '97 21' Sport Nautique |
Posted By: MrMcD
Date Posted: May-16-2022 at 5:14pm
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You can run an alternate fuel line from the inlet on the fuel pump to a separate gas can, the pump will suction gas to your carb and you should run perfectly if the fuel pump is in working order. You may need to prime the carb to get the pump working but as soon as the engine starts you should be pulling fuel from your gas can. Work vented and always be careful. A fire would get really bad fast with open containers sitting around. You would also screw a bolt into the old fuel line feed to keep it from draining fuel into your boat while you use the alternate fuel supply. If this works you are only looking at the tank and lines for blockage. If it does not work your fuel pump is shot or you have a blockage at the carb.
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Posted By: BaccoBouncer
Date Posted: May-16-2022 at 5:19pm
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MrMcD. Thanks! will do. P.S. I'm doing this outside on the water, so well vented and I can jump in the water if needed. ------------- '97 21' Sport Nautique |
Posted By: BaccoBouncer
Date Posted: May-16-2022 at 8:44pm
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It was a stuck carb bowl float. I took the line off of the check valve at the gas tank and ran directly from a 5 gal tank. Still happened. Then took the fuel line off of the carb and let the mech pump, pump into another can. Worked fine. While the line was of the carb I decided to just spray a ton of carb cleaner up into the carb hopefully getting it into the bowl. I also sprayed a bunch of carb cleaner into the fuel line and then hooked it up and ran it. Much better with only the occasional drop but only at high RPM's. Ran circles in the lake with occasional starvation, but quick recovery. Pulled the fuel line sprayed more carb cleaner up into the bowl and now it runs great. I also spayed a bunch of marvel mystery oil into the carb as it was running to get some coating back on the cylinders since the carb cleaner might of taken some of the oil off the cyl walls. Thanks everyone for your input. ------------- '97 21' Sport Nautique |
Posted By: MrMcD
Date Posted: May-16-2022 at 10:57pm
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Nice work, creative way to fix it. Sounds like the fuel in the bowl dried up and made the needle stick. ------------- |
Posted By: KENO
Date Posted: May-17-2022 at 6:33am
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So it was deja vu all over again after all it seems to me that if the float was stuck shut for some strange reason you wouldn't have gotten any gas to the bowl and it wouldn't run for 1 to 3 minutes over and over again like you mentioned in post #1. It wasn't stuck open since it would have been flooding the engine. But like last year, all your banging and spraying did something to something and now it runs I'd be looking around some more for what's really happening and why.
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Posted By: BaccoBouncer
Date Posted: May-17-2022 at 8:54am
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What I was picturing was happening is that the float was sticking up (closed) not down. The needle seat was sticky. The bowl had to completely drain and it needed a good hit to drop and let more fuel in. But in most cases it was too late for the motor to catch. After a bit the float would fall again. Crank the motor and it will start up once the bowl fills. It had the issue less when it was idling. I imagine it got more hang time with a low level so it call fall and fill again before the bowl ran dry. At high RPM's it didn't fall fast enough so happened more often in that case. My theory anyway. ------------- '97 21' Sport Nautique |
Posted By: MrMcD
Date Posted: May-17-2022 at 11:44am
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I have never run into anyone having the issue you are having with the float. Ken is probably right, something else is in play also. Why not pull the bowl and install a new needle and seat. You might see what is causing your problem. It is only 4 screws and a new gasket. If it is a Holley Carb. ------------- |
Posted By: BaccoBouncer
Date Posted: May-17-2022 at 11:46am
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Maybe I'll do that. ------------- '97 21' Sport Nautique |
Posted By: KENO
Date Posted: May-17-2022 at 3:06pm
 I'd probably also look to see if there's a fine inlet screen where the fuel enters the bowl when you unscrew the fuel line adapter from the bowl and make sure it'd clean. You may have already cleaned it by spraying the carb cleaner into the inlet.
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