Merc 5.0LX stalls won't start

[HarryC]

I have a 1990 Merc 5.0LX which started stopping occasionally while under throttle, it would restart after a minute or so. It stopped the last time and would not restart. It will not fire even with starting fluid.Acellerator pump pumps fuel. I have been thru the Thunderbolt IV trouble shooting chart. Replaced coil as it's resistance measurement was just at the edge of acceptable range, no luck. One of the tests had me strike one of the distributor sensor wires to ground and look for spark, there was a weak spark so I replaced the distrbutor pickup still very weak spark in plug on top of engine (probably not enough to fire under compression) I am considering the ignition module but they are pricy and the trouble shooting chart says it should be ok. Any ideas?

 

[ICC]

Re: Merc 5.0LX stalls won't start

Harry, if you are not getting a hot blue spark at the plug when grounded on the engine then I would carefully go back through any troubleshooting charts you may have. I am not an expert on Mercruisers but spent plenty hours working on engines. I recently bought a 1989 Maxum with a Mercruiser so if you find out the problem please post the solution.<br /><br />Good Luck<br />Mike

 

[HarryC]

Re: Merc 5.0LX stalls won't start

Went thru charts again, but cannot definitely say ignition module, but nothing else left!! Module ordered, I'll post if it fixes<br />HarryC

 

[ICC]

Re: Merc 5.0LX stalls won't start

I hpe it works too ! Too many times have I bought a part only to find out it didn't fix the problem, wish you well.<br /><br />Mike