87 cherokee 4.0 idle problem
#1
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Model: Cherokee
87 cherokee 4.0 idle problem
I just got an 87 wagoneer limited the Cherokee style with the 4.0 and it idles like crap and wont go anywhere or Rev when I hit the gas have changed tps and iac still no change and I have unhooked o2 sensor no difference was told might be egr valve but not sure need some help here guys can't figure this one out all vacuum lines seem to be hooked up
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Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Did you adjust the TPS?
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I'm gonna check fuel pressure and Injectors today and the Guy before me said he adjusted it o and its running very rich and the fumes are coming from the hose coming from the valve cover front one
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So did some work on it today I have sprayed around all the vacuum lines and no leaks that I can tell and I tried unplugging the iac and there was no change at all when I hit the gas it wont Rev up at all it sometimes backfires if I unplug the map while running it dies what could it be
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#8
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Ok I just had this same thing happen and on mine it was the fuel pressure regulator it was bypassing and allowing all the fuel to return to the tank causing very low fuel pressure
#10
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Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
So did some work on it today I have sprayed around all the vacuum lines and no leaks that I can tell and I tried unplugging the iac and there was no change at all when I hit the gas it wont Rev up at all it sometimes backfires if I unplug the map while running it dies what could it be
#11
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No if you unplug the map it will still run and it should still rev up the map only tells the PCM what the berometric psi is for lean mixture
#12
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Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
BS. When you unplug the MAP the ECU sees full throttle due to vacuum drop and richens up the mixture til it dies. Go try it on your Jeep.;
#14
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Year: 1990
Model: Cherokee (XJ)
Engine: 4.0