no spark
11-30-2011, 03:37 PM
#1
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Year: 1984
Model: Cherokee
Engine: 2.5 Litre
no spark
I've got an 84 XJ with the 2.5L. I bought it running and did a clutch job on it. I let it sit for 2 weeks and when i came back it was difficult to start but once started it ran fine. I ran it for several days in a row and it would always restart fine as long as the battery was kept on a tender. It then sat again for a couple weeks and when i went to start it it was difficult to start and once started it backfired and now it wont start at all. It has a new battery, new solenoid, new ignition coil, new plugs and the ICM checked out good when tested. Im stumped on where to go next. Thanks
11-30-2011, 03:40 PM
#2
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Year: 1984
Model: Cherokee
Engine: 2.5 Litre
p.s. All the fuses and relays check out good too. And when i take a light tester to the coil there is a solid ground on th (-) side and power going to th (+) side
12-03-2011, 04:50 AM
#4
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Year: 1999
Model: Cherokee
Engine: 4.0
First thing I recommend with ANY no-start is to test the spark.
Pull a plug, keep it attached to the plug wire, place the plug electrode near a good engine ground. Have a buddy crank the engine while you watch. You are looking for a strong, blue, snapping spark. Yellow/orange/white indicates a weak spark, which may not be enough to start the engine.
If spark is good, then move onto fuel. You need to have a certain amount of fuel pressure to fire it up. Try a splash of gas or a shot of starting fluid into the intake. If it starts and runs for a bit with this technique, then you've identified a "fuel delivery" problem.
The above two tests are quick and easy and will help you narrow down the ROOT CAUSE of your no start. Don't throw any more parts at this. Test your way to a solution!
Good luck and check back to let us know how it goes....
Pull a plug, keep it attached to the plug wire, place the plug electrode near a good engine ground. Have a buddy crank the engine while you watch. You are looking for a strong, blue, snapping spark. Yellow/orange/white indicates a weak spark, which may not be enough to start the engine.
If spark is good, then move onto fuel. You need to have a certain amount of fuel pressure to fire it up. Try a splash of gas or a shot of starting fluid into the intake. If it starts and runs for a bit with this technique, then you've identified a "fuel delivery" problem.
The above two tests are quick and easy and will help you narrow down the ROOT CAUSE of your no start. Don't throw any more parts at this. Test your way to a solution!
Good luck and check back to let us know how it goes....
12-05-2011, 11:51 AM
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Year: 1984
Model: Cherokee
Engine: 2.5 Litre
Thank you for your help. I've actually already deducted that it is a no spark problem. i am getting fuel and obciously air. I have power to my ignition coil coming from the ignition control module and a ground from the ICM as well. there is a wire that was aftermarket spliced into the ground btwn the ICM and coil that runs under the dash and stops. The problem is a lack of spark from the coil and im lost.
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