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Old 06-10-2018 | 06:51 AM
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Question 502 not starting

I was running 3600 rpm's for 45 min and engine just died. Like I shut off the key and won't restart. It didn't get hot, oil press was ok. I put over 15 plus gallons of new gas on top of a 3/4 tank just to be safe. I was able to get jump packs on both batteries , no start. The batteries are brand new. Any idea. I think it is electrical. Not fuel, or battery related. ?????
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Old 06-10-2018 | 07:08 AM
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Is it cranking over? Check kill switches? Check 50amp breaker?
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Old 06-10-2018 | 08:14 AM
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Do you have MSD box?
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Old 06-10-2018 | 08:17 AM
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I know you said electrical, but I would still pull fuel separator and confirm no water in gas.....good luck.
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Old 06-10-2018 | 07:48 PM
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Engine cranks over fine. I got it to run today for about a minute. Died, just as it did yesterday. Not sure if I have an MSD (Ignition)? checked all "kill" switches, Breaker not tripped. Where is the fuel separator?

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Old 06-10-2018 | 07:55 PM
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Most mercs have the fuel separator on the stbd side of engine on front. Right above sea pump.
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Old 06-10-2018 | 09:42 PM
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The first thing I would do is pull the water sep fuel filter and dump the liquid into a clear glass. Let it sit for 20-30 mins. Water will settle on the bottom.
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Old 06-11-2018 | 05:46 AM
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If you are going to be diagnosing and repairing yourself you need to start with the basics.

Get a inline sealed spark tester and fuel psi tester. These should always be performed first and then computer scanned for codes.

Something like this should be fine for checking fuel psi. Not enough people have these. There are different fuel psi values for these motors depending on year and engine serial #. So ask here for values when you go to check.

This type spark tester - most all parts stores have them. Everyone should have on in there tool box. Only $10-$15.
Look online to get visual idea (if there is spark) on what is weak (dim spark) vs strong (bright)spark.
Lisle 20610 Inline Spark Tester
by Lisle
Link: http://a.co/93Ha5YY

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Old 06-11-2018 | 04:24 PM
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Distributor module
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Old 06-11-2018 | 07:23 PM
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It's funny you say Distributor Module. I had a Z-28 with a 350 in it. When it would get hot it would just shut down. it ended up being the (brake pad shaped) module in the distributor. Popped it out, put in the new all was fine. I could not idle the car enough to replicate the problem. Probably needed a load long enough to create issue. I thought of that as soon as it happened. I didn't think there was a module in my distributor. I started the engine today and it ran for 10-15 min. like no problem ever. Now I can't trust it to go out on it. I'm going to have a local mech.look at it. At least he will have all the computers/code readers needed. Thanks guys
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