chuuck

I am having an issue to where, when it is at idle it does great. When I start to drive it sputters and won't drive faster than 15 to 20 with out flicking the gas pedal alot. I'm lost because I changed the throttle position sensor, crank position sensor, gave a tune up with new plugs wires cap and rotor. I am stumped thanks for anyone's help

Laxbro26

I have the same problem, i used a bws tps and they suck. Everytime it acts up i put in another one, lifetime warrantee and ut usually solves the problem. How many miles on your tps?

JeepDeep

What year Cherokee? It may be adjustable.

chuuck

The Jeep is 1988 and the tps is brand new this morning

Cherry_key

You need to adjust your tps... I Had the same problem and once i adjusted the tps it was a huge difference. there is no way you can just buy a tps that is adjustable (like ours, other years are fixed) put it in and go.. it requires fine tuning that you can do your self. You just need a volt meter. if you cannot find a write up let me know.

cruiser54

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: 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.
If you see more than 1 ohm of resistance 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.
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. 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.
Revised 11-28-2011

chuuck

OK thanks I will give it a try and then report back

chuuck

I have it apart and cleaning the throttle body, I was thinking is it possible that the exhaust is plugged up? Not bad enough to stop completely but enough to make enough back pressure to choke out the engine. The truck has 250,000 miles and is 24 years old. While looking under it, she looks like it might be the stock cat.

cruiser54

Possible.