alindquist

So I take the boat out on Friday (1999 Cobalt 232) to check out the hardware in town for the poker run, and everything starts out just fine. Run for about 15-20 minutes and everything is going great. All of the sudden the engine dies at about 3300RPM's. This has happened to me before and the last time replacing the high pressure fuel pump fixed it. I thought minor set back, I got it started back up and idle over the the beach and replaced the high pressure fuel pump with a new one. Boat starts up, runs great for another 15-20 and then it happens again. Exact same scenario. It seems it's not the fuel pump. I haven't started digging into it yet but it was kind of weird. Thinking back the last time this happened (around February) there was a hesitation and a little surging going on before it died. This time it was like someone just turned off the engine. I'm starting to think it could be a corroded ground or something electrical. Anybody have any ideas? Someone suggested replacing the fuel filter which I'm going to do today.
If it matters here is some additional information:
1999 7.4GI
Serial 4110176452
Model - gipwtr
Thanks,
Aaron

Baja_342

I had a similar problem last year. If it's a major ground, other things could act up or not work as well. Could be horn, lights, etc. I used these other things to help diagnose while on the trailer. It's awfully hard to play with wiring while underway

Knot 4 Me

Control module in the distributor? I had one go bad in a Merc motor and it would run fine for a while and then die.

alindquist

Thanks for the info fellas... I'm going to play around with it a little today and see if I can find something. Where do I locate the control module. Is is actually inside the distributor? Is there a way to tell if it's bad?

Knot 4 Me

The bulletin Merc had out at the time stated that the bad control module had either a grey or green stripe on it. Can't remember which color was noted. However, it turned out I had the good colored module but mine was bad anyway. Took a regional Merc rep most of the day with his laptop hooked up to finally figure out the problem. The boat would start and run fine at the first of the day and then after 10 -20 minutes of running it would start to miss and then quit. Then it would not want to start. If you let it set for some time it would fire up again and run but then would want to quit again after only a few minutes of running. Had to be engine heat affecting the module.

alindquist

I have a feeling that I guessed wrong and it's the low pressure fuel pump, I found a good deal on one and it's in route and should be here Friday. If that doesn't fix it i guess I'll keep diggin. The boat has ran really good all summer so I should have known I was due for a break down. I'll also check into that controller, but being this is a Volvo, who knows if there even is one on this engine.

Knot 4 Me

Both are GM motors and the distributors most likely are the same. Did you check your fuel pressure while running?

alindquist

I unfortunately don't have a fuel pressure gauge on the boat or a way to test it... I'll have a new pump on Friday and if that doesn't do it I'll probably have some more questions for you. Thanks again.

jbraun2828

Is this a carbed motor? Fuel pressure guage will tell the story. I just had a problem with the cam my fuel pump rides on. It was wore. boat would run perfect up to 3500 then it would die feeling like it was running out of fuel. Fuel press was only 2lbs. I have the setup with fuel pump mounted on top of the sea water pump. Fuel pump was fine.

alindquist

It's an EFI motor. I really wish there was a fuel pressure gauge on it, it would be very help fully. I might have to install one in the future.