cruiser54

I put it in a somewhat prioritized order. For instance, if you've never done it, you should do 1 thru 5 for sure.

You noticed the font size? I'm old, too!! Or are you talking punctuation and capitalization?

I have posted up 25 of my write-ups on Cherokee Forum which deal with the Renix Jeep issues. Here is a link and an outline of them. http://www.cherokeeforum.com/f51/cruiser54s-mostly-renix-tips-153657/ Revised 11-02-2012 * means instructions have been written. 1-Ground refreshing* 2-C101 connector refreshing** 3-Connector and relay/receptacle refreshing* 4-Coil/ICM contacts* 5-Checking sensor grounds* 6-Sensor ground upgrade** 7-CPS testing and adjusting* 8-TPS testing and adjusting* 9-ECU connector refreshing* 10-Trans plug connector refreshing* 11-Throttle body and IAC cleaning* 12-Setting your 4.0 to #1 TDC* 13-Renix Distributor indexing** 14-Restoring throttle butterfly adjustment* 15-Rear main seal diagnosis* 16-Vacuum test for exhaust restriction* 17-HO engine into Renix* 18-Improving the instrument panel ground* 19-Headlight harness installation* 20-4WD shifting tips* 21- Renix EGR valve test* 22- Renix vacuum harnesses** 23- CPS timing advance mod* 24-4.0 Engine date codes* 25-Valve cover mod* 26- Snugging up intake manifold bolts 27- CPS wiring bypass 28- Setting base idle 29- Renix O2 sensor diagnostics

I have used the later exhaust manifold with the O2 sensor welded into the upgraded down pipe which is made in two 45* angles to clear the driveshaft and has no "crush". You can have an EGR tube bung welded into the later manifold also.

Have you tested your CPS? You're right on regarding replacing the oil cap.

Maybe I shoulda posted this first....... Renix Ground Refreshing The Renix era XJs and MJs were built with an under-engineered grounding system for the engine/transmission electronics. One problem in particular involves the multiple ground connection at the engine dipstick tube stud. A poor ground here can cause a multitude of driveabililty issues, wasted time, and wasted money replacing unnecessary components. The components grounding at the dipstick tube stud are: Distributor Sync Sensor, TCU main ground, TCU “Shift Point Logic”, Ignition control Module, Injectors, ECU main ground which other engine sensors ground through, Oxygen sensor, Knock Sensor, Cruise Control, and Transmission Sync signal. All extremely important stuff. The factory was aware of the issues with this ground point and addressed it by suggesting the following: Remove the nut holding the wire terminals to the stud. Verify that the stud is indeed tightened securely into the block. Scrape any and all paint from the stud’s mounting surface where the wires will attach. Must be clean, shiny and free of any oil, grease, or paint. Inspect the wire terminals. Check to see that none of the terminals are crimped over wire insulation instead of bare wire. Be sure the crimps are tight. It wouldn’t hurt to re-crimp them just as a matter of course. Sand and polish the wire terminals until clean and shiny on both sides. Reinstall all the wires to the stud and tighten the nut down securely. While you’re in that general area, locate the battery negative cable which is fastened to the engine block just forward of the dipstick stud. Remove the bolt, scrape the block to bare metal, clean and polish the cable terminal, and reattach securely. Another area where the grounding system on Renix era Jeeps was lacking is the engine to chassis ground. There is a braided cable from the back of the cylinder head that also attaches to the driver’s side of the firewall. This cable is undersized for it’s intended use and subject to corrosion and poor connections at each end. First off, remove the cable end from the firewall using a 15mm wrench or socket. Scrape the paint off down to bare metal and clean the wire terminal. Reattach securely. Remove the other end of the cable from the rear of the head using a 3’4” socket. Clean all the oil, paint and crud from the stud. Clean the wire terminal of the cable and reattach securely. A suggestion regarding the braided cable: I prefer to add a #4 Gauge cable from the firewall to a bolt on the rear of the intake manifold, either to a heat shield bolt or fuel rail bolt. A cable about 18” long with a 3/8” lug on each end works great and you can get one at any parts store already made up. Napa has them as part number 781116. A further improvement to the grounding system can be made using a #4 cable, about 10” long with 3/8” terminals at each end. Attach one end of this cable to the negative battery bolt and the other end under the closest 10mm headed bolt on the radiator support just forward of the battery. Napa part number 781115. If you want to upgrade your grounds and battery cables in general, contact Jon at www.kelleyswip.com. He makes an incredible cable upgrade for a very reasonable price. Revised 11-28-2011

I think this is a good idea to do regardless.

Has nothing to do with the TCU. The only wires anywhere near there that have anything to do with the TCU are in the big plugs near the trans dipstick tube or they're the ground wires at the engine dipstick tube stud.

Check your CPS wiring and make sure it's not near the exhaust manifold.

Yes, it would. Orange wire at the fuel pump.

See if you have 12 volts to the pump, at the pump. Also, there is a critical ground for the fuel pump behind the left taillight.

You mean like this? Yesterday, I helped my Uncle Jack off a horse. Versus: Yesterday i helped my uncle jack off a horse

I'm gonna have to disagree with you here. The "brick" and the DRB, while not real sophisticated because of the Renix system, are quite useful in diagnosing issues. I have the DRB.

http://www.eautoworks.com/Putco-H4--9003-Heavy-Duty-Headlight-Upgrade-Wiring-Harness-PRD7540.aspxI'm with Hornbrod on this one. Check it out. very common. Put an auxiliary headlight harness on and never have this problem again.

I hope so. Did you happen to notice you left your teeth in your avatar?

http://www.cherokeeforum.com/f51/free-d30-cad-bypass-91-a-38629/

MT2500 aka "the Brick"

Are you sure it was the fuel pump relay you changed? There's more than one inaccurate schematic for the relays. Should be 2nd one back from the front.

This old codger loves happy endings. On to the next problem............

You caling me a codger? LOL. 218 is the temp that the fan is supposed to turn on. Excellent way to fill a closed system BTW. This old codger uses the same method.

Correct. Must be a coincidence.

Sorry. I thought you had an earlier MJ and were calling the C101 a bulkhead connector, which it is. But just clean it out the same way as described above.

You can never go wrong with NGKs no matter what it is.

Temp SENSOR for the fan is in the radiator on the driver's side. The temp SENDER for the gauge is located on the head, rear, driver's side. Two different animals and unrelated.

Check grounds or refresh grounds? There is a difference. Have you checked the "trans" side of the TPS using this: 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 only a flat three-wire TPS mounted on the throttle bodyand it provides data input to the ECU. It 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. 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. 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, 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. 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 square four-wire connector side of the TPS. If you have ENGINE ISSUES check the flat 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 09-22-2012