Saw this on craigslist. Heres what the ad says.............

I bought this as a mechanic special, and another car came along and i moved on to the new car. It had transmission problems when i bought it, so i bought a new tranny and front drive shaft. I didn't install them though. I am selling these with the Jeep. Title in hand.--- Great vehicle if your into off-roading.---
Body is in decent condition. Needs paint. Minor dings.---
4X4---
Automatic---
4 Door---
Inline 6---
Limited Edition---



I called the guy and he said it has 203k on the motor,he said he bought it about 4 months ago and drove it home and the transmission would pop out of gear in 3rd.He said he bought a new transmisson (has 70k on it). I can swap out the trannys no problem. Just wondering what you guys think. I can also get the truck painted for 200 bucks at my school so what do you guys think?? Oh and he wants 600 bucks for it. I can probaly talk him down to 500

 

How much and what year model? Needs a little tlc and some work but not to bad..

 

i think he said he could get it for 500 bucks, dam dam dam

 

Yeah nice buy and here is the kicker. I will bet a six pack the tranny is just fine. Once you get it started and running get back on the forum and let me know what year it is and then I think I can tell you why it was popping out of gear.

 

I did not buy it yet,the guy also said it is running a little rich becuase he said when he revs it up it leaves a exhaust mark on the ground?? Oh and the year is a 1990

 

Buy it. There are two issues and they are related. The IAC is coked up with carbon and the TPS which has a signal to the tranny which keeps locking and unlocking the converter. Clean the IAC and replce and calibrate the TPS and your new XJ will run like a top and the tranny will be just fine.

This is the procedure for checking the TPS and adjusting the same.

Located on the right side of the front of the throttle body. To test, disconnect the connector at the TPS. Check the voltage at TPS connector pins B (Ground) and A (5.0 volt supply) with the ignition on. If you see about 5 volts, hook up the connector again. and check the voltage at TPS terminals C (positive) and B (Ground) with the ignition on and the throttle plate closed. You should notice approximately 0.8 volts. If you see that voltage, your TPS and wiring should be ok. If not, you'll have to adjust the TPS to get that voltage. If you cannot adjust the TPS to get that voltage, you'll have to replace the TPS and adjust the new one properly. Also, with the voltmeter hooked (terminal C) up and the ignition on, move the TPS arm down and back up slowly and watch the voltage. The change should be increasing and smooth. If there are any dead spots or it is not smooth, it probably needs to be replaced.

> What does it do? The voltage is interpreted by the ECU to determine current engine operating conditions. Just as a note to you, the AUTOMATIC TRANSMISSION versions have 2 integral connectors (1 for ECU and 1 for tranny). If you have the auto, make sure you're checking the right connector.

Update: Suggestion: If you are having intermittant idle / surge issues and can't quite get the voltages to set right - before going out to buy a new TPS try checking your ground connection. Renix engines are notorious for having bad / faulty ground connections as a result of age and not so great design in the connectors. A common "fix" is to add a jumper ground wire from the TPS ground that bypasses the connector and harness entirely.

First - Check ALL of your engine ground connections.
Second - Check the ground wire from your TPS to the firewall to ensure that there is not a poor circuit to ground. If the circuit resistance is high then the voltage reading will be incorrect to the ECU and the computer will not know what the throttle opening is actually at & the engine will not run or SHIFT properly

 

You were just waiting for the opportune time to share those tidbits weren't you, Blue?

BTW: Nice tips.

 

fricken blue, fixin em before people buy em, keep it up blue

 

Go for it! Looks like a sweet deal, and if Blue's advice solves the problem, you can sell the tranny and shaft and come out of this almost even, dollar-wise. You just can't beat that.

BTW... Blue, that was some slick info. I raise my glass to you, Sir.