realy tired of this

OK OK here it is. I have a 90 xj 4.0 that is a big prob. The jeep ran good when i bought it, 2 weeks later the idle goes south and starts running realy bad. i replaced plugs and wires cap and rotar and it still runs like donkey dung. I had the coil tested and had to replace the ignition control module. it sometimes idles at about 1000 rpm's and it most times idels at 2500-5000 rpm's. The tb is clean and i have replaced the air injection valve. Their is a distinct smell of raw fuel out the exhaust and it spuders on steady driving. when you step ont the gas it runs like a champ but normal driving is horible.Idle is realy ruff to. anyone with tech help would be apreciated.

my mind says tps and ox sensers but im no expert

My Jeep acted similar to that when my TPS went bad, but it also threw on the check engine light. But if the Throttle Position Sensor fails it can give the symptoms that you describe. I don't know if there is a check for this part but IIRC it was pretty cheap when I replaced mine and is worth a try. If it doesn't prove to be a defective TPS I would check for a vaccume leak

Check out your MAP sensor to, that's what mines was.

Also check the Idle Air Sensor (or Controller).

In other words, check ALL the sensors. LOL

Thats what I'm doing and mine isn't nearly as bad as yours, just some high idle sometimes and low milage.

Check for vacuum leaks. I had one to my map sensor and it caused all sorts of problems. Unhook the egr also, they cause tons of problems, but this'll tell you if that's causing your problem.