Jeep Grand cherokee Laredo

1997 JEEP GRAND CHEROKEE
180,000 MILES • 6 CYL • 4WD • AUTOMATIC
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TYWELLS
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I have a 1997 Jeep Grand Cherokee Laredo with a 4.0L. I cant get it to start. It has no spark, I chenged the coil, and checked the cap and rotor and they where fine, and there are no blown fuses either. I notiesed that the O2 sensor wires where rubbing agensted the drive shaft, so i dont know if that would have anything to do with it or not?
Aug 22, 2011 at 8:42 PM
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CARADIODOC
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Absolutely. Fix those wires, then check for voltage on the small coil positive wire. You might catch battery voltage there for one second after a helper turns on the ignition switch, but what's important is it must come back during cranking.
Aug 22, 2011 at 9:16 PM
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WRENCHTECH
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Doc is correct about that having to be fixed but it won't cause a "no start".
You need to tun a few more tests to isolate what might be causing it.

All "crank, no start" conditions are approached in the same way. Every engine requires certain functions to be able to run. Some of these functions rely on specific components to work and some components are part of more than one function so it is important to see the whole picture to be able to conclude anything about what may have failed.


1) Test for spark at the plug end of the wire using a spark tester. If none found, check for power supply on the + terminal of the coil with the key on.


2) Test for injector pulse using a small bulb called a noid light. If none found, check for power supply at one side of the injector with the key on.


3) Use a fuel pressure gauge to test for correct fuel pressure, also noticing if the pressure holds when key is shut off.
Aug 22, 2011 at 9:43 PM
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