96 Mercruiser 5.7LX refuses to start

[chrisbrace]

Need some help diagnosing my starting problem.

I have a 96 Bayliner 2050LS Capri with a Mercruiser 5.7LX. Was out on the weekend and after about 4 hours on the water the engine died during a run and would not restart.

I had installed a brand new battery an hours before the trip so I know that was good and not the issue. Had topped off the tank with about 50ltrs of fuel before the trip so suspect that its not fuel that either.

The engine now will crank over but will not fire.
Have checked all the fuses under the dash (all ok), checked kill switch was in the run position but still nothing. Checked the wiring harness is plugged in and it appears to be fine. Its been regularly serviced all its like on time and never had any real issues before.

I removed air cleaner from carb and can see fuel when I pump the throttle so i figure its getting fuel....

Any ideas/help/manual links would be appreciated

 

[Silvertip]

Re: 96 Mercruiser 5.7LX refuses to start

Check for spark. I suspect you have none. A service manual is your friend since it has the trouble shooting flow charts and all the voltage test points and test procedures.

 

[Dshow]

Re: 96 Mercruiser 5.7LX refuses to start

If you don't have a timing light, connect a spare spark plug to the wire to see if you have spark.

 

[chrisbrace]

Re: 96 Mercruiser 5.7LX refuses to start

Yup, I'm about to do exactly that tonight and see what i can track down. My gut feeling in the Coil of something in the distrubutor but how to figure which is the problem

 

[chrisbrace]

Re: 96 Mercruiser 5.7LX refuses to start

can someone give me a link to a service manual for my engine?

 

[retrota79]

Re: 96 Mercruiser 5.7LX refuses to start

dont suspect anything anymore, just because you got a new battery and fuel does not say much, to many times people think its good, Double check just incase it could save you a bunch of greef in the end ( not saying thats what it could be but its to easy to just assume) start small and work way up, let us know if you found spark there once

 

[chrisbrace]

Re: 96 Mercruiser 5.7LX refuses to start

dont suspect anything anymore, just because you got a new battery and fuel does not say much, to many times people think its good, Double check just incase it could save you a bunch of greef in the end ( not saying thats what it could be but its to easy to just assume) start small and work way up, let us know if you found spark there once

Good point. I'll start with the basics and the things I have changed, and work it up from there.

 

[6meter]

Re: 96 Mercruiser 5.7LX refuses to start

I believe there is a sticky on the subject in the Adults Only section at the begining.

 

[chrisbrace]

Re: 96 Mercruiser 5.7LX refuses to start

Ok guys and update.
spent last night checking a few things. Removed and cleaned the battery terminals. Tested Coil input and got 12v ok also checked the kill switch is also ok.
checked the spark plug leads while cranking and still no spark.
Cleaned the distributor cap, found plenty of build up on the contacts, cleaned and replaced, still no go.
removed the coil and had it tested at my local auto electrician's shop and its working perfectly.
So now I'm thinking towards the distributor and the sensor inside it.

 

[Bt Doctur]

Re: 96 Mercruiser 5.7LX refuses to start

Or a shorted tach, that would kill the spark.

 

[chrisbrace]

Re: 96 Mercruiser 5.7LX refuses to start

Update:
OK I got a hold of the test procedure for my engine and it appears to be the ECM (Ignition Module).
The part number is 807264-3 with a Nippon Denso number of 131300-2360. When we took it off and opened it up low and behold it had water in it!

A bit of hunting by my friend Google and I found that I need a conversion kit as the replacements are not available. Will keep you posted

 

[dingdongs]

Re: 96 Mercruiser 5.7LX refuses to start

see if its recoverable by drying out as a new one is not cheap.

 

[Bondo]

Re: 96 Mercruiser 5.7LX refuses to start

When we took it off and opened it up low and behold it had water in it!

Ayuh,... Now the Big Question is;... Where'd the water Come From,..??

 

[chrisbrace]

Re: 96 Mercruiser 5.7LX refuses to start

Yes indeed the new one cost me about $700 (NZD). Im going to see if i can salvage the old one as a spare.

As to where the water came from in the first place i think i know that. The Ignition Module sits a bracket on the back of the distributor which happens to be directly below the joint of the rear seat back and the bulkhead. Having been stored outside this winter (sadly lost my garage storage) i think that water has been sitting on the joint and slowly seeping through the road/weather cover i had made. The fix it to either relocate the module to else where or put a drip cover over the top of it and further weather proof the casing.

In all I learnt a great deal about the electrics of my boat and hopefully other can learn from the experience.