D_Conrad

im having problems shifting into reverse when the Jeep is cold, 80% of the time it will not work until it warms up, but on rare occasions it will work right after starting up. once the Jeep is warm its works fine with no problems. also, when cold it will not shift out of first until it reaches high RPMs if i let it get high, and release the gas it will shift. does anybody have any ideas on what this could be? or anybody have the same problem? any help will be appreciated. thanks in advance.

tjwalker

1. Ensure fluid is RED in color, at the proper level on dipstick, and doesn't smell burnt

2. The throttle position sensor is directly involved with shifting characteristics of the AW4. Testing it would be recommended. How to do that is detailed below.

3. Ensure TV cable is adjusted properly.
http://naxja.org/forum/showthread.php?t=1015963

4. If ALL of the above checks out and you still have trouble with shifting when cold, it is possible that you have an internal problem with low "line pressure". A shop could verify that for you if you parked it there overnight, but it needs specialized equipment. If that is the case, it is time to shop for a different transmission; salvage yard is your best option.
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RENIX TPS
(Thanks to Joe Peters from NAXJA for this information)

MANUAL TRANSMISSION:

RENIX manual transmission equipped XJs have a three-wire TPS mounted on the throttle body. This manual transmission vehicle TPS provides data input to the ECU. The manual transmission TPS has three wires in the connector. Wire "A" is positive. Wire "D" is ground. Remove the three-wire connector from the TPS. Key ON, measure voltage from "A" positive to "D" ground. Note the voltage reading--this is your REFERENCE voltage. Now, reconnect the three-wire connector to the TPS. Key ON, back-probe the connector at wires "B" and "D". Measure the voltage. This is your OUTPUT voltage. Your OUTPUT voltage needs to be seventeen percent of your REFERENCE voltage. Adjust the TPS until you have achieved this percentage, if you can't achieve the correct output voltage replace the TPS and start over.

AUTOMATIC TRANSMISSION:

RENIX automatic transmission equipped XJs have a TPS with two connectors. There is a three-wire connector, same as the manual transmission vehicles have, and it is tested the same as the manual transmission equipped vehicles--FOR ENGINE MANAGEMENT RELATED ISSUES. However, the automatic TPS also has a four-wire connector. For the automatic transmission equipped vehicles the four-wire connector provides data to the TCU. Disconnect the four-wire connector. Key ON, measure voltage between "A" positive and "D" ground. Note the voltage. This is your REFERENCE voltage. Now, reconnect the four-wire connector to the TPS. Back-probe the connector at wires "B" and "D". Measure the voltage. This is your OUTPUT voltage. Your OUTPUT voltage needs to be eighty-three percent of your REFERENCE voltage. Adjust the TPS until you have achieved this percentage, if you can't replace the TPS and start over.

So, if you have an automatic equipped XJ your TPS has two sides--one side feeds the ECU, and the other side feeds the TCU. If you have TRANSMISSION issues check the four-wire connector side of the TPS. If you have ENGINE issues check the three-wire connector side of the TPS.

For those with a MANUAL TRANSMISSION--the TPS for the manual transmission XJs is stupid expensive. You can substitute the automatic transmission TPS which is reasonably priced.

D_Conrad

ok thank you ill look into those. could it be a shift solenoid? i dont wanna do a trannie swap till i check every possible thing first. i do have a spare trannie though.