stumbling problem when accelerate

I have a stumbling problem when I accelerate upon the 1st start of the engine that day. And then the TPS code comes on. XAfter it warms up and I shut it off for a while, restart and it runs great with no code. So.... is the stumbling causing it to trip the code, or is the TPS causing the stumbling. OR is it something else?

And when you rev the engine while parked, it runs great.

Thanks

If it says tps, it probably is. I have a similar stumble right now but I get an 02 sensor code. A few years back I did have a tps related issue that was almost identical to the o2 issue im having now, but swapping in a new tps solved the issue.

I have had success cutting the tps open and cleaning the contact strip from corrosion. When water gets in it it will leave a thin film that jacks up the resistance values and give you the problem. You could try that in attempt to avoid the cost of a new purchase if you wanted. Its worked several times for me.

Best way to find out is to just swap tps's with a known working one and see if the problem goes away. If you know someone with a similar model year, then theres no cost to pinpoint the problem.

Always post year/engine in every thread.

On 87-90, the TPS is adjustable. If yours is one of those, check your adjustment.

On all years of the 4.0, the TPS can be tested with a meter and a manual.

Test and adjust if applicable before replacing. But concentrate on the TPS if the code is pointing you that direction....

That was the problem... Everything runs great now. Even helped with the upshifting. Doesn't hang at 3.5K RPM before going into overdrive.

$34.99 at pep boys

OK.. that wasn't the problem. It helped, but still stumbles. Since it's not doing it all the time, i can narrow down when it does it. Accelerating on a left turn. So from a stop light making a left turn. Straight ahead, or a right turn, not bad, but nothing like the left turn.

And only when it's cold. After it warms up and sets for a while. Then it's fine. Even on left turns.

I would like to think something in gas tank, but the only doing it when it's cold is puzzling.

Thanks


94 XJ - 4.0 automatic.

mine is doing the same thing. stumbles of idle when cold, when making sharp left turns, and occasionally when i hit bumps. its not consistant which is making it very hard to pin point whats wrong. all new plugs, cap, rotor, O2 sensor just replaced, TB just cleaned and it still does it.

when i pulled the old plugs they were white. could it be a MAP sesor problem? crappy fuel pump? bad injector? doesnt throw any codes though

94, 4.0 with aw4

I just scored a 88 wag aw4 and it stutters when driving at high way speed trys to stall or shutter stops after it want I have ran seafoam and new filter and has good
fuel presure

jpcherokeekid said:

mine is doing the same thing. stumbles of idle when cold, when making sharp left turns, and occasionally when i hit bumps. its not consistant which is making it very hard to pin point whats wrong. all new plugs, cap, rotor, O2 sensor just replaced, TB just cleaned and it still does it.

when i pulled the old plugs they were white. could it be a MAP sesor problem? crappy fuel pump? bad injector? doesnt throw any codes though

94, 4.0 with aw4

Click to expand...

I still have it too. Havn't done much to try and solve the problem right now. I'm thinking fuel pump. But it only does it when cold. After the jeep is warmed up, then shut it down wait 15 - 20 minutes, she runs great. Only when cold and accelerating, espically on left turns. right turns seam fine.