rough running 4.0

[Danno]

I've put new plug wires,rotor, cap, spark plugs in and it still feels like it is running on 5 cylinders. I unplugged the distributor wires one by one to see if I could isolate it to one cylinder with no luck. It's a 1997
Any ideas? Anything this year model is notorious for? Thanks!!!

 

[red91]

I've put new plug wires,rotor, cap, spark plugs in and it still feels like it is running on 5 cylinders. I unplugged the distributor wires one by one to see if I could isolate it to one cylinder with no luck. It's a 1997
Any ideas? Anything this year model is notorious for? Thanks!!!

jump one of the plugs around the circuit, and see if maybe you didn't get a bad plug.

Cheapest test I can think of to start with.

not to be crass danno....are all the wires in the RIGHT spot ?

nothing notorious to the 97 that I can think of...if it was running decent before...its something you've replaced.

 

[jeepsx3]

Run it long enough for the computer to set a code.

 

[98JeepXJ]

I get the impression that it was running rough before the tune-up... (?) If so, and the tune-up didn't help, then it may be a fuel injector issue. To check for this: with the engine running, unplug each fuel injector one-by-one. If you unplug one, and it doesn't make a difference in how it's running, it's highly possible that you just found a bad injector.

Note: Unplugging injectors with the engine running will turn on the check engine light. To reset it when you're done, just unhook the battery for a few hours/overnight, and it'll go off.

Also, How's the air filter look? A severely clogged air filter will simulate an engine miss, but won't always set a code for the check engine light...