Wild Comanche Posted February 12, 2016 Share Posted February 12, 2016 Hey Members, I'm new to Comanche Club and have a problem I haven't figured out yet. I have a 1989 Jeep Comanche Pioneer with a 4.0l and 4-sp automatic. I have done a conversion using a 1992 block and head. I have kept the Renix computer system, with a 1999 intake and 1996 throttle body bored to 60mm, Clifford exhaust headers with a Flowmaster muffler. 4-hole injectors rated at 21.5/lbs per hour. I'm getting 45 PSI of fuel pressure in the fuel rail. The engine starts and idles good. But has very poor acceleration. I have used the HESCO throttle body adapter for the newer throttle body. Did the 1989 Comanche 4.0l with an auto 4-spd. transmission have 2 throttle position sensors? I have one male 3-wire plug that I haven't found a female plug to fit. Any help will be appreciated. Link to comment Share on other sites More sharing options...
HOrnbrod Posted February 12, 2016 Share Posted February 12, 2016 The TPS on Renix system MJs and XJs with auto transmissions has two connectors, one for the ECU and one for the TCU. This is the un-used 3-wire connector you are referring to. You need to get the TPS for the auto. Link to comment Share on other sites More sharing options...
cruiser54 Posted February 13, 2016 Share Posted February 13, 2016 Yes. ^^ 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 Link to comment Share on other sites More sharing options...
Wild Comanche Posted February 13, 2016 Author Share Posted February 13, 2016 Thanks for the info.... I will follow through with that advice............. Link to comment Share on other sites More sharing options...
Rockfrog Posted February 14, 2016 Share Posted February 14, 2016 Hey Members... I have one male 3-wire plug that I haven't found a female plug to fit. Any help will be appreciated. Ummm ... The flat male 3 wire connector (if it's the one I'm thinking of see below for more) is for the engine side of the equation. It needs to be connected for the ecm to be able to do it's thing. The square 4 wire plug is for the transmission (TCU) side of things. It will affect transmission shifting and functionality. So if the 3 wire connector on the engine harness is not connected to the TPS ... That is the most likely cause of the issue. Both connectors come off the same harness "trail" so should be right beside each other. The other 3 wire connectors in the general vicinity are the MAP sensor (green), O2 sensor (under the manifold and shouldn't reach), and the CPS lead (should be near back of the head only has 2 wires in 3 prong connector). Everything else is two lead (ECT, Injectors, Knock, and e-fan) and then the 4 lead for the IAC ... I only really mentioned ones around that area. Having done this same conversion a while back (and making a few location changes) I had a few WTF moments myself when I went to plug it all back in. Link to comment Share on other sites More sharing options...
cruiser54 Posted February 14, 2016 Share Posted February 14, 2016 Hey Members... I have one male 3-wire plug that I haven't found a female plug to fit. Any help will be appreciated. Ummm ... The flat male 3 wire connector (if it's the one I'm thinking of see below for more) is for the engine side of the equation. It needs to be connected for the ecm to be able to do it's thing.The square 4 wire plug is for the transmission (TCU) side of things. It will affect transmission shifting and functionality. So if the 3 wire connector on the engine harness is not connected to the TPS ... That is the most likely cause of the issue. Both connectors come off the same harness "trail" so should be right beside each other. The other 3 wire connectors in the general vicinity are the MAP sensor (green), O2 sensor (under the manifold and shouldn't reach), and the CPS lead (should be near back of the head only has 2 wires in 3 prong connector). Everything else is two lead (ECT, Injectors, Knock, and e-fan) and then the 4 lead for the IAC ... I only really mentioned ones around that area. Having done this same conversion a while back (and making a few location changes) I had a few WTF moments myself when I went to plug it all back in. I stole your photo................... Link to comment Share on other sites More sharing options...
Rockfrog Posted February 14, 2016 Share Posted February 14, 2016 Want the one without my chicken scratch? Link to comment Share on other sites More sharing options...
Wild Comanche Posted February 14, 2016 Author Share Posted February 14, 2016 Hey, " Rockfrog " and " cruiser54 " - - Thanks for the info.. Those pictures are very appreciated!!!!!!!!!!!!!!!!!!! I should have joined Comanche Club a long ways back. Better late than never................. Link to comment Share on other sites More sharing options...
cruiser54 Posted February 14, 2016 Share Posted February 14, 2016 Want the one without my chicken scratch? Sure, but I kinda like the original...... Link to comment Share on other sites More sharing options...
Rockfrog Posted February 14, 2016 Share Posted February 14, 2016 The bring your own crayons edition ... Link to comment Share on other sites More sharing options...
Rockfrog Posted February 14, 2016 Share Posted February 14, 2016 With a TPS hooked up ... Disregard the wire colors, or the slightly different looking TPS. Link to comment Share on other sites More sharing options...
cruiser54 Posted February 15, 2016 Share Posted February 15, 2016 I love the original!!!! Link to comment Share on other sites More sharing options...
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