502 not firing
 

I have a major issue going on with a 502 in a 272 Baja Boss that i rebuilt last year for a friend. To start the motor has around 25hrs since rebuild from last year. When we took it out last weekend to a local restaurant here in Galveston it ran perfect the entire way there which was about 45 min at 3500rpm. Reached the dock, tied up, went inside for about an hour and when we tried to leave the boat would not fire. I tried everything including starter fluid.... nothing! Needless to say we left boat overnight in a local marina after being pulled in. The next morning when we arrived to load it up I hit the key and it stated right up. Now its doing it again this weekend. I cant find anything wrong including checking all grounds! Very frustrating. Please help!

Check distributor. Sensor?

I did an oil change on it yesterday and checked all wires. The only thing I have not done is check the distributer cap and rotor. I check all plugs to the distributer and ECM. Everything looks good.

Pull a plug and see if your getting spark. Check the dist for condensation.

fixx
 

the hall effect in the dist is most likely bas,,commin problem..also check coil wire..

Might check the ignition module in the distributor.

when your engine wont start,,,use a test light at the coil,,,ground the clip,,stick the pointed end of the test light thru the ground side wire of the coil,,,have some one crank engine,,you should see the bulb in the test light flashing on and off,,,while the engine is cranking,,,if not hall effects sensor or module is bad,,,,,if you want to try this while the boat is still in running order,,pull the fuse on the electric fuel pump and test at coil,,hope this helps,,let us know how u make out

Thanks for the advice! Should have know not to get on that boat with no tools! Damn the luck....

check the deadman switch, the one that usually has a rope attached to it

Update.... Well the problem persists... Since the last post we have decided the coil may be breaking down and changed it but still no change. Once you make a run and shut down the motor it will fire briefly for a second and then nothing. If it wont start on the initial light off your screwed till many hours later. He took it out today and still having the same problem. The dead man switch was bypassed by the previous owner years ago, coil was changed and checked rotor and cap. What a pain this is.....