96 XJ 4.0 Auto

With changing frequency, my trans will not upshift until at least 2500rpm (slightly lower on 1-2 shift), shifts up at a maximum of 3000rpm, no kickdown, no torque converter lockup. I have been able correct this best on the road byletting it decel to 35-40mph and quickly cycling the ignition. Doesn't always work, and sometimes it will eventually revert to its bad behavior during the same drive. Sometimes just no torque converter lockup in 4th gear until I gas it a little (which defeats the purpose). I have cleaned out the Trans position/neutral safety/backup lamp sensor meticulously, and sealed it up with black silicone. For several months afterwards, it ran perfectly, then had the same issues again more and more. Fluid and filter have been changed regularly and now has MOPAR ATF+4 in it. No fluid abnormalities. Just over 190,000 miles. 4wd.

DFlintstone

There is a button on top there to free/adjust the tranny kick-down cable. I set mine with about zero play. I'm not positive that's correct, but seems OK. Somebody likely will post the correct procedure for "auto setting " it.

Your TPS might be the next suspect. Even yours could be checked...not sure how!

tjwalker

1. Here is how to adjust the TV cable.

https://www.cherokeeforum.com/f2/free-quick-fix-41821/

2. Here is how to verify your throttle position sensor.

The throttle position sensor is connected to the throttle shaft on the throttle body. It sends throttle valve angle information to the PCM. The PCM uses this information to determine how much fuel the engine needs. The TPS is really just a simple potentiometer with one end connected to 5 volts from the PCM and the other to ground. A third wire is connected to the PCM. As you move the accelerator pedal with your foot, the output of the TPS changes. At a closed throttle position, the output of the TPS is low, about a half a volt. As the throttle valve opens, the output increases so that, at wide open throttle, the output voltage should be above 3.9 volts. Testing can be performed with an electrical meter. Analog meter is best. You are looking for a smooth sweep of voltage throughout the entire throttle band. While slowly opening and closing the throttle, take note to the movement of the voltmeter needle. There should be a direct relationship between the needle motion to the motion of the throttle. If at anytime the needle moves abruptly or inconsistently with the movement of the throttle, the TPS is bad

You should have 5 volts going into the TPS. At idle, TPS output voltage must be greater than 200 millivolts. At wide open throttle (WOT), TPS output voltage must be less than 4.8 volts.. The best is to use an analog meter (not digital) to see if the transition from idle to WOT is smooth with no dead spots. With your meter set for volts, put the black probe on a good ground like your negative battery terminal. With the key on, engine not running, test with the red probe of your meter (install a paper clip into the back of the plug of the TPS) to see which wire has the 5 volts. One of the other wires should show .26V (or so). The other wire will be the ground and should show no voltage. Move the throttle and look for smooth meter response up to the 4.49 at WOT.

Perform the test procedure again and wiggle and/or tap on the TPS while you watch the meter. If you notice any flat spots or abrupt changes in the meter readings, replace the TPS.

The TPS is sensitive to heat, moisture and vibration leading to the failure of some units. The sensor is a sealed unit and cannot be repaired only replaced. A TPS may fail gradually leading to a number of symptoms which can include one or more of the following: -

NOTE: The throttle position sensor is also DIRECTLY involved with transmission shifting characteristics! It should be verified early in the troubleshooting process, when a transmission issue is suspected!

• Poor idle control: The TPS is used by the ECU to determine if the throttle is closed and the car should be using the Idle Air Control Valve exclusively for idle control. A fault TPS sensor can confuse the ECU causing the idle to be erratic or "hunting".
• High Idle Speed: The TPS may report faulty values causing the engine idle speed to be increased above normal. This is normally found in conjunction with a slow engine return to idle speed symptom.
• Slow engine return to idle: A failing TPS can report the minimum throttle position values incorrectly which can stop the engine entering idle mode when the throttle is closed. Normally when the throttle is closed the engine fuel injectors will be deactivated until a defined engine RPM speed is reached and the engine brought smoothly to idle speed. When failing a TPS will not report the throttle closed and fueling will continue causing the engine to return to idle very slowly.
• Engine Hesitation on Throttle Application: The TPS is also used by the ECU to determine if the driver has applied the throttle quicker than the Manifold Air Pressure sensor can read. The fueling is adjusted accordingly to cope with the sudden increase in air volume, however a faulty sensor can cause the ECU to ignore this data and the engine will "hesitate" when applying the throttle. In extreme cases with the engine at idle, a sudden application of full throttle can stall the engine.
• Engine Misfire: A fault TPS can report values outside the denied acceptable range causing the ECU to incorrectly fuel the engine. This is noticeable as a slight misfire and can trigger the misfire detection software and/or Malfunction Indicator Lamp (MIL) light on the dashboard. Extreme cases can cause excessing misfires resulting in one or more cylinders being shut down to prevent engine and catalytic converter damage.

3. ATF+4 has resulted in shifting abnormalities in some (not all) AW4 transmissions.

Radi

I bet your TPS is acting up. Things that fix themselves by cycling the ignition are usually electronic. Adjusting the TV cable is good to do in any case, it may also be causing the problem.

You may or may not be happy with the ATF+4. Some have no problems, others develop some slippage after switching from Dex III with higher miles. Just mentioning it so you are aware if issues crop up.

96 XJ 4.0 Auto

FIXED!!! Just wanted to let any searchers for the same issue know. The Throttle Valve Cable adjustment fixed it, surprisingly. Haven't had any issues since, but I just smashed up the front end pretty good. Hoping it is fixable without much work at the body shop.