I have a rough idle while Jeep in is gear. I have replaced the following parts: CPS, TPS, Distributor Cap, Rotor, Oxygen Sensor, Plugs and added injector cleaner to the gas. What else could be the problem? Please....someone help me before I go insane and broke replacing everything. Thanks. :banghead:

How does it run? Do you have a missfire during driving?

Have you check Tranny Fluid. Clean the IAC and Throttle Body and all the vacuum ports with some Throttle Body Cleaner.

How does it run? Do you have a missfire during driving?

Have you check Tranny Fluid. Clean the IAC and Throttle Body and all the vacuum ports with some Throttle Body Cleaner.

My Jeep runs excellent at all speeds above idle. It only happens wwhen I am stopped and in gear. The roughness was a lot worse prior to replacing the sensors I mentioned above but there is still some roughness which is very annoying. I have sprayed carb cleaner into the throttle body and directed it into the IAC port. The trans fluid is ok. Thanks.

You should completely remove the Throttle Body to clean it thoroughly.

When was the last time the Wires were changed?
Could be one of the injectors. have you performed a Power balance test?

set the idle to 1500 RPMS. Do this by sticking a piece of paper or something thin between the throttle lever and contact point. Record the RPMS, then pull one of the injector electrical connectors and record the RPMS, plug it back in and do each of the other injectors the same way.

If when you pull one of the enjector plugs NO/LITTLE CHANGE (drop in RPMs) is observed then then you found your bad injector and/or wiring to that injector.

Engine & Tranny mounts

I fought rough vibrating idle while in gear for about 60k miles on our 95. I also knew that there was a problem with the exhaust header being cracked. When I was fixing the header I replaced the engine mount. The left side fell apart when I removed it. Now it is a night and day difference at idle in gear.

Is the Jeep crank for maybe a little to long before it starts? Is it the I6 engine?

Is the Jeep crank for maybe a little to long before it starts? Is it the I6 engine?

Yes, the engine seems to turn over longer than normal before starting. Ususally about 5 to 10 seconds. It is an I6 4.2L. Thanks

From what I have been told, the fuel regulator often fails to keep pressure to the injectors.

Try this, turn the key to the position just before the starter cranks, you should see all the lights on the dash light up at this point, keep it like this for 10-15 seconds then turn the key forward to turn the starter, if the engine fires up sooner then it would if you started it normal, you may have a bad regulator.

The regulator is on the fuel rail, and I have been told it's an easy replacement, be warned, make sure the pressure is released before you remove the regulator.

If you are unsure how to take the pressure off try this, make sure the engine is COLD then stuff rags under the regulator and rags covering the unit as it's removed SLOWLY.

I know you have no good reason to,but I would like to know if and when you test the regulator I would like to know how it turns out.

Good luck!

to relieve the Fuel Pressure: Remove the FUEL PUMP RELAY from the POWER DISTRIBUTION CENTER (fuse block in engine compartment, behind battery) and start engine, it might not start, in this case let it crank for a few seconds, if it starts let it run til it dies, then attempt to restart it. Then proceed with the Regulator removal.

Thanks dksob81, I think you posted that before, but for the life of me I could not remember it.

U need to do is unscrew the gas cap Then depress the shrader valve on the fuel rail(Gas will spray). This will properly relieve pressure

That sounds quicker!

Wow, you just went from changing input sensors for no reason due to a rough idle to replacing the fuel pressure regulator because it cranks too long? What exactly are you trying to fix in this thread? The people who said you have bad motor mounts were most likely correct. Unibody design, crappy motor mount design. Let me guess you turn the ac onand it's worse right?