Mechanics

CRANKS BUT WILL NOT START

1993 Jeep Grand Cherokee • 5.2L V8 AWD Automatic • 160,000 miles

The engine compartment of my jeep got soaked from a coolant issue I was having and now it will not start. I have fuel but no spark. Also no power to the coil, ASD relay appears to be working properly.
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Jansenmounce
January 9, 2014.




Please elaborate on "ASD relay appears to be working properly." If it is, you should have 12 volts at the ignition coil. How are you measuring this voltage? Why do you say the fuel pump is working?

Caradiodoc
Jan 9, 2014.
I got fuel pressure at the fuel rail and I can feel the relay working when I turn the key on. I think something must have got wet under the hood

Tiny
Jansenmounce
Jan 9, 2014.
This is the common and incorrect way to check things. The Engine Computer is going to turn on the automatic shutdown (ASD) relay for one second after turning on the ignition switch. That is why you mistakenly think you have fuel pressure. What you have to check for is if that relay turns on again during engine rotation, (cranking or running). If it does not, the fuel pump will not continue to run, and there won't be any voltage to the ignition coil, injectors or alternator field.

Measure that voltage at the ignition coil again, but see if it comes back when you crank the engine. Have you checked for diagnostic fault codes?

Caradiodoc
Jan 9, 2014.
Yes I have a code 41
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Tiny
Jansenmounce
Jan 11, 2014.
41 An open or shorted condition detected in the generator field control circuit

That isn't related to a no-start condition.

Did you check for proper operation of the ASD relay during cranking?

Caradiodoc
Jan 11, 2014.

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