View Full Version : 95 PCM GT40 Nautique wont restart warm

eric rautenberg
07-01-2008, 12:44 AM
"Ok guys. You're smarter than me but I listen well. Unless you're my wife. 95 GT40 EFI runs awesome. Just can't shut her down. On a warm restart, fires strong, tries to catch idle, then shuts down. Thought I had it nailed to the high pressure fuel pump but my dealer suggested replacing the low pressure pump first ($30 vs $300). She'll start if I tap on the high pressure pump with a wrench while cranking when warm. Any advice before I replace the HP pump? I've heard rumor of vapor binding on this boat."

08-22-2008, 11:48 AM
I would try replacing the main/fuel pump relays first- if you are not near PCM dealer you can substitute Volvo/OMC part # 3854138

10-17-2008, 09:44 AM
"Need help too! I have nearly the same problem on same engine. Starts and runs great. Won't restart once engine is warm/hot but cranks great and tries to catch idle. Replaced fuel filter, distributer cap and rotor (inexpensive) but no change. The expensive smaller pump is located closer to the engine and gets very warm. When I turn the ignition key to on (w/o cranking) both fuel pumps run for a second or so making me think they are fine. The plastic connector on the wire connector to the small pump doesn't quite snap into position but don't think that's an issue. Eric, what did you find with yours? What exactly is the relay if I were to replace it?
Much thanks, John"

10-18-2008, 07:49 AM
Update. I found if I turn the key so the pumps come on (but not crank) for 5 sec and turn the key back off then repeat 3 times it will start when the engine is warm. I'm guessing then that I have some vapor lock even though I have owned the boat for 10 years and it never did this before with no changes in use. John

10-18-2008, 06:21 PM
"OK. checked the fuel pressure. 39psi prior to start, 35psi idle and goes up to 39 again for acceleration. The times it doesn't start the pressure is next to nothing. Most the time turning the key 1 click from off the pumps pressurize to 39psi. Sometimes they only go to like 15 and it won't start. One time it didn't pressurize at all. I'm guessing the relay. Opinions?"