99Cherokeesprt

My 99 manual transmission Cherokee is stuttering balking on acceleration and idles rough sometimes but when given accelerator settles down. I have put in new rotor, cap, spark plugs, spark plug wires. No codes showing and I have checked the air filter and it looks good. Can someone help.

VTJeep

Haha. No CEL so no putting it on a diagnostics computer? Neither did I. Turned out codes will store without tripping CEL. Either way, I'm gonna shoot for o2 sensor failure probably your bank2. But if it's one, it's both! What I mean is change both cause the other one is probably on its way out, too..

Edit.. OR! It's fuel delivery related. Get LOW on gas and drop the tank and open er up to see whats going on. If your 97+ then pump/filter is in-tank. Does it ever pull for air real hard and stumble when at idle? If so could be a sign of running "dead lean"..

99Cherokeesprt

It was hooked up to a diagnostic computer and that also said no codes. I showed a code before the rotor was replaced then after it showed no codes. It said the O2 sensor low voltage so I will replace those and see how it goes.

VTJeep

Oh, right on. Either way, o2's are kinda expensive, so maybe do some more trouble shooting.

The low voltage might not be the o2 itself.. Could be bad ground? Idk. I've been dealing with this issue for a while and with two new sets of OEM o2's it will act up. Only when I get the CEL cleared, though..
CEL cleared.
It acts up.
CEL comes back on.
It runs fine..

I do have a vac leak somewhere, and there is a possibility the clock spring (which grounds the TPS) is bad and resulting in the hesitation...

Gee oh Dee

Check for good fuel pressure when its doing this.

VTJeep

^this. I still say drop tank. Your 99 has a plastic screw cap that is easy to deal with.