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Crusader 7.4 MPI "warm" starting problem

T

TYSGUY

New member
I have a pair of Crusader 7.4MPI closed cooling V-drive engines in a 2001 Gibson 44'. Both engines are original and have 100 hours of freshwater use. On cold starts, both engines fire right up as they should. The problem I am having is that the starboard engine does not want to start right back up after running it for 15 minutes to an hour like it did when it was cold. This only occurs when the engine is still warm and trying to start it after sitting for an hour or two. The port engine fires right up on warm starts, but the starboard is very difficult to start. It turns over and over just fine, but will not start easily or at all. Frustrated with this yesterday and not wanting to come in on one engine, I used starting fluid several times and it would fire up with the fluid sprayed in, but die again after it burned through. Finally, on my last attempt, I was able to keep it running after the starting fluid burned through and it ran fine and normal for 20 minutes back in to the marina. After getting in the slip and shutting down, I tried starting it 30 minutes later and same problem of not starting. This morning after sitting all night and cold, it fired right up as normal. The problem has been occurring for several months now. I have fresh fuel in the tanks, changed the fuel water seperator filters, cleaned flame arrestor, new plugs & wires and rotor. Any thoughts would be appreciated.
 
Okay. You might have an ignition problem--which you need to confirm by pulling a plug wire when it does this and checking for spark. If it's NOT ignition related, then you need to borrow a fuel pressure tester (Auto Zone or buy own--not that expensive). See what pressure the 'good' engine sees when running, restarting, and--most importantly--immediately after being shut down. Then compare with the 'bad' engine.

I suspect (if it's not ignition related) that an injector or two is leaking down and flooding the motor. Pressure testing will tell you. It might also not be pressuring back up at re-start; the test will reveal that as well.


Jeff
 
Jeff, Thanks for your reply. I did check for spark and its functioning fine. Plus, its starts and runs on starting fluid when sprayed into the flame arrestor, so I confident that its a fuel supply related issue when warm. I have been told to check the anti siphon valve ( not sure if it has one) as well as the fuel regulator valve. I have also heard it could be a computer related issue not telling the fuel pump to turn on when starting warm. I will start with checking the fuel pressure per your advice and go from there.
 
Start with the fuel pressure test; it will provide the most insight. and be sure to check it running, under load, at WOT...idle fuel pressure isn't enough to assess the 'health' of the pump.

You are also likely to have more filters in the fuel system than what you identified in your first post. Might want to download the parts listing to you know what you have and where it is.

The anti-syphon valve isn't likely to be at the root of a 'won't start when warm' issue...
 
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