'89 Wrangler 4.0 has developed a periodic miss while at idle rpm's while sitting at a stop....say waiting for the light to change. Vehicle has an auto tranny.
Jack
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20 years ago
Periodic Miss
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20 years ago
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20 years ago
Thanks for the advice. Was thinking of using the Bosch Plugs. Any comment on that or recommendation on plugs?
Jack
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20 years ago
Thanks for the help and the reference.
Jack
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20 years ago
Dirty idle air passage could do the RPM bit.
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Also clean/check the connectors for your electrics. TPS, CPS, MAP, etc
A miss is timing, you might have a plug/wire that's on its last legs. Or you could have a failing CPS (Crankshaft Position Sensor) but usually when that goes the engine simply stops.
First thing I'd do is clean the throttle body and give it a can of injector cleaner.
(I'm basing this on the 93 4.0 which is different than the 89) YMMV