757 Grafix

Hey guys, new to the forum, but long time looker and creeper , anyways i just flushed my coolant in my 88 Cherokee, burped it and everything and went to take her for spin. Start heading down my driveway and it will not shift into third or overdrive. Goes into reverse, neutral, 1-2 fine, but no third or overdrive. Get it into the garage and i notice a small puddle (2") right under the slip yoke eliminator. Any thoughts of what could have happened or what i should do next? Fluid level was fine. Thanks for any advice! Keep on Jeepin'!

757 Grafix

bump anyone have this problem?

BotakBeng

You might wanna try searching "transmission solenoid".
Here is a solenoid replacement write-up.

GL.

757 Grafix

Thing about mine is it wont manually shift into third either
thanks though!

excess650

I have no idea as to what happened, but you can try shifting manually by unplugging the TCU or removing its fuse from the wiring harness. 1-2 should get you 1st unless you rev to 4500+ and then it will pressure shift to 2nd. 3 will get you 3, D will get you 4th which should be a .70-1 OD in your year trans. R should get you R.

If the manual shifting works, then you have an electrical problem. The TPS is a common cause and is adjustable on the RENIX models. There is a VSS on the tailshaft of the trans......could the leak be coming from the VSS? It has a 3 lead electrical connector and will be close to where you found that puddle.

The NSS sometimes causes issues, and then the brake pedal switch which can inhibit lockup.

PM me your email address for AW4 manaual and diagnosis manual.

757 Grafix

Little update, hooked the computer up to my buddies snap on scanner, it came up with the TPS being bad, so the scanner told us how to check the connection. We tried the connection, scanner said it should be about 5, its 4.65 coming into the sensor but nothing coming out. Hopefully a new TPS will fix it!

excess650

The TPS on the RENIX XJs are adjustable(!) so may not need replacement unless it can't be adjusted within spec.

757 Grafix

How exactly do you adjust it? And whats the spec for that? Thanks for your help!

1991Jeep_Man

Im more curious as to how you scanned a Renix computer??

excess650

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.

crystalion

At the same time it could be that the converter itself is going bad.

757 Grafix

Two computer ports on the right side fender, must have the right connector though. Used a Snap-On Solus Pro.

757 Grafix

Thanks a lot ill give it a shot!

757 Grafix

Well, reference voltage was 4.65, output was .004, ill have a new TPS tomorrow morning so we'll see how that goes!

757 Grafix

Put a new TPS in and it runs like a top! Thanks guys