1988 OMC 5.0L missing at 1500+ RPM's, runs good at idle

[jszczepanski]

Having a problem on a 1988 24' Bayliner Trophy with an OMC 5.0L. Runs fine at idle, but once you try to accelerate, the engine starts missing. Coil, plugs, points and condensor have been replaced. Anybody's have any ideas? Replace the distributor?

Seems to be more of an electrical problem as opposed to a fuel issue.

 

[astuckey]

Re: 1988 OMC 5.0L missing at 1500+ RPM's, runs good at idle

I had the same problem with a 4.3l last year. I first diagnosed the problem, by putting a jumper wire to the + side of the coil, and to the battery, and the problem went away. Try this first, and see what happens, then post back here. Do not leave the wire connected, or you will burn up your points.

 

[LAC_STS]

Re: 1988 OMC 5.0L missing at 1500+ RPM's, runs good at idle

I had the same problem as both of you and my problem was fixed by the wire on the + side of the coil also. It is just a test to diagnose it like astuckey said dont leave it on for too long.

The real problem with mine was that the wire that went from the alt to the coil was really a resistance wire. It had gone bad. So I bought a ballast resistor for $10 and put it in the old resistance wires place.

But next time you have time start the boat and try it. If it is missing or running like crap run a wire from the + side of batt to the + side of coil. If prolem goes away then you know whats wrong. If not then disconnect the wire and keep looking.