chadsomers

Ok all, i just bought a 1988 jeep cherokee with the automatic, anyways of course the motor was dirty so i cleaned it. OK before i get to what i need help with let me start by telling you what i did. The jeep ran and shifted great no problems at all, all it needed was a new neg. cable (so i replaced) and a new air filter( i replaced) i did notice that my oil gauge was not working at all... ok so i washed the motor after replacing those things and i noticed my oil gauge started working after and now it has a low idle and will not shift gears right, no power. feels like it wont shift in passing gear???? tps?

car5car

Remove distributor cover and let it stay open for 30 min.
Probably water went inside. No big deal.

cruiser54

I'm gonna make a guess that you got the Throttle Position Sensor wet and ruined it.

Radi

I'm guessing the same as your guess.

cruiser54

And I'm guessing you're guessing right .

So, I guess I'll post TPS adjusting procedures for the OP when he gets his new TPS. Takes the guesswork out of adjusting it.




RENIX TPS ADJUSTMENT
Before attempting to adjust your TPS be sure the throttle body has been recently cleaned. It's especially important that the edges of the throttle butterfly are free of any carbon build-up.
IMPORTANT NOTE: With the Key OFF, and using the positive (red) lead of your ohmmeter, probe the B terminal of the flat 3 wire connector of the TPS. The letters are embossed on the connector itself. Touch the black lead of your meter to the negative battery post. Wiggle the wiring harness where it parallels the valve cover and also over near the MAP sensor on the firewall. If you see more than 1 ohm of resistance, or fluctuation in your ohms reading, some modifications to the sensor ground harness will be necessary. The harness repair must be performed before proceeding. I can provide an instruction sheet for that if needed.
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 and they're clearly embossed with the letters A, B, and C. Wire "A" is positive. Wire "B" is ground. Key ON, measure voltage from "A" positive to "B" ground by back-probing the connectors. Note the voltage reading--this is your REFERENCE voltage. Key ON, back-probe the connector at wires "B" and "C". Measure the voltage. This is your OUTPUT voltage. Your OUTPUT voltage needs to be seventeen percent of your REFERENCE voltage. For example: 4.82 volts X .17=.82 volts. 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 flat 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 square four-wire connector clearly embossed with the letters A,B,C, and D. It only uses three wires and provides information to the Transmission Control Module. THIS SQUARE FOUR WIRE CONNECTOR IS USED FOR TRANSMISSION/SHIFTING RELATED ISSUES ONLY. Key ON, measure voltage between "A" positive and "D" ground. Note the voltage. This is your REFERENCE voltage. 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. For example 4.8 volts X .83=3.98 volts. 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.
FOR AUTOMATIC TRANSMISSION RELATED 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.
Revised 08-27-2012

Radi

Well be my guest!

chadsomers

The motor is not missing at all. just no power when in gear and shifts at like 2000rpm and fast..... ........... i have a friend who has a jeep with the same motor and year and she is going to let me use her tps and see if its my problem.. if so ill get a new one....

cruiser54

What? Just test the one you've got. It requires the same meter you're gonna need to adjust the TPS from her Jeep when you install it on yours, then readjust hers when you put it back on her Jeep . What are you thinking?

chadsomers

ok so i installed the NEW napa TPS. and did not change anything, should i undo the battery and hook back up maybe ????????

chadsomers

ok so i just took for a drive, ran same so i pulled over and unhooked the square harness side(tranny wire) and i had all my power back but but but not shifting till 5 to 6000 rpm???? any help is better than no help, its my only rig and have 3 kids with winter coming on,.

cruiser54

The TPS MUST be adjusted per the instructions I posted already.

sthon

Some people you just can't help =/

cruiser54

RTorrez1

Hey, chadsomers. If you are going to listen to anyone one here, Listen to cruiser. I have read a lot of his comment and he pretty much hit the nail right on the head every time. NO I am not trying to suck up. LOL

CPTslackass

I hear on planet Renix, cruiser is the god. He eats C101s for breakfast!

He's right. What better advice to take then from a guy who worked at jeep during the renix days?