MPEM problem 98 challenger 1800. No start either engine

[mark32141]

Hi, ive had a intermittent no start either engine problem. Both Turn over always but not spark most of the time. Candoo pro doesn't show anything. New DESS post and lanyard. New battery. New ground straps. No beeps most of the time. Ive cleaned all connection I can find. so far. I find that on the F1 fuse block both the F2 and F3 have low voltage. about 4 volts. I can feed 12 volts into the Guage 5 amp Fuse and both engines start. Fuel guage does not work but that may be a bad guage. What do ya think??

 

[Bdk1282s]

I had a similar problem , but would run good sometimes then just suddenly die, crank and crank and kill battery. Rinse, repeat. Ended up being bad ground from battery to mpem. Also replaced rectifiers , spark plugs , tightened all wiring , rebuilt carbs , new battery , new lanyard, new battery terminals , neutral safety switch bypass, fuel selector valves etc. Could also be bad dess post or switch , bad mpem (last thing I'd do) , loose or bad fuse. These things vibrate quite a bit and are rough on the water , I was very surprised a very clean , new looking ground wire was the cause of a summer of problems, which were quite frustrating and resulted in 2 tows and many short trips on the water.