88Dutchman

Okay I read about how to adjust the TPS with an automatic. First you adjust to the proper output voltage for engine managment and then you agjust for proper output voltage for transmission management.

Thing is is that would you not mess up the first adjustment when doing the second adjustment being both are done rotating the TPS?

Thanks

Crazy 8s

From Cruiser54's excellent tips that you and your Jeep will both be benefited by...

https://www.cherokeeforum.com/f51/cr...x-tips-153657/

RENIX TPS ADJUSTMENT

Before attempting to adjust your TPS, there are two things that need to be done.

1) 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.

2) With the Key OFF, and using the positive (red) lead of your ohmmeter, set on the lowest scale, 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.

TPS ADJUSTMENT FOR ENGINE ISSUES

Both RENIX manual and automatic transmission equipped XJs and MJs have a flat three-wire connector to the TPS which provides data input to the ECU. The three wires in the connector are clearly embossed with the letters A, B, and C. Wire "A" is positive. Wire "B" is ground. DO NOT UNPLUG THE CONNECTORS !! 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. Loosen both T-20 Torx screws attaching the TPS to the throttle body and rotate the TPS until you
have achieved your desired output voltage. Tighten the screws carefully while watching to see that your output voltage remains where it is supposed to be. If you can't achieve the correct output voltage, replace the TPS and start over.

Sometimes, after adjusting your TPS the way outlined above, you may experience a high idle upon starting. If that happens, shut the engine off and reconnect your probes to B and C. Start the engine and while watching your meter, turn the TPS clockwise until the idle drops to normal and then rotate it back counterclockwise to your desired output voltage.

TPS ADJUSTMENT FOR AUTOMATIC TRANSMISSION ISSUES

RENIX automatic transmission equipped XJs and MJs 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 outlined above—FOR ALL 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. First off, DO NOT UNPLUG THE CONNECTORS !! Key ON, measure voltage between "A" positive and "D" ground by back-probing the connector. 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 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. The square 4 wire connector is just not used.
Revised 12-15-2013

KnightKrawler

I had the same question. Is there a +/- % that can allow both engine and trans to be in proper range? I'm curious what types of issues I'd have if the values for the trans isn't set properly?

cruiser54

The Engine side is critical. The Trans side will be fine if the Engine side is adjusted correctly.

I use the Trans side only for diagnosis of suspected trans issues.

88Dutchman

Actually that's the exact post I read that I was a bit confused about Crazy 8s but thanks for the link anyway.


Also thanks for clearing that up Cuiser54. I have been going over many of the technical items on your list as a precaution.


Next on my list is checking the CPS. Every once in a while after I run in and out of a store or something I have to give it two tries before it starts.

cruiser54

We're here to help.

If that 88 were mine, I would systematically go through Tips 1 through 5 right off the bat. The test results from Tip 5 are very important.

If you have soldering skills, or would like to develop them on a fast track, do Tip 27.

I guess what I'm trying to say is that you should do those Tips before messing with sensors and such.

88Dutchman

I did get rid of the C101 connector so I had lots of solder practice Saturday.

cruiser54

Cool. So you're down to Tips 1,3,4, and 5!!