cruiser54

I had identical symptoms on my wife's XJ. I released the terminals from the plastic holders, cleaned and crimped them , and reinstalled. worked great. Yours seems like a more permanent solution.

The motor is probably not the issue. Renix is not voodoo for crying out loud. Good chance you compromised the fuel pump by running a 20 plus year old tank low on gas, allowing the pump to suck up debris. Do a fuel pressure test first.

Well, you're getting air into the intake manifold from somewhere else then. Intake manifold bolts tight? EGR valve hanging open?

That tells me you're getting idle air somewhere. else. Sure you got the throttle butterfly adjusted properly?

Fix the frickin' leak first. You know it's an issue. Could be as simple as tightening some intake bolts and/or spraying some vacuum hoses/connections. Studies have shown that more MJs get fixed out in the garage/driveway than in the living room using a keyboard and monitor.

Check the "trans" fuse first............

New motor? Whoa. Soundsl like a loss of fuel pressure. How mechanically inclined are you?

With it idling, see what happens as you turn that Torx- headed screw clockwise.

Your wiper motor and switch both ground at the point described in the following write-up. If not done already, I suggest doing the ground refreshing found in the link in my signature. The C101 connector if you have an 87 or 88. Improving the Instrument Panel Ground The ground point for the complete instrument cluster on your XJ or MJ is located up under the driver’s side dash. If you lay on your back and look up under there with a flashlight, without wearing a hat, you will see a black wire attached to a shiny piece of metal almost directly above the hood release knob. The screw will have either a ¼” or 5/16” head on it. This ground point is responsible for handling the ground circuit for the following items: Dome lamps, Seatbelt and key warning, trans comfort switch, wiper switch, headlamp switch and delay module, fog lamp switch, cargo lamp switch, all instrument panel grounds and illumination, power windows and door locks, cruise control dump valve, and a few more things. The problem is that where the ground point is located does not have a good contact with the chassis where the ground should be. The solution is simple. Make up a jumper wire with #10 gauge wire about 10” long. On one end, crimp on a ¼” round wire terminal. On the other end, crimp on a 3/8” round wire terminal. Remove the screw from the existing ground wire and attach the small terminal of your jumper so that the original wire and your new jumper share the same attaching point, one over the other. Look above the driver’s side plastic kick panel just forward of the top of the hood release knob. You will see an 8mm stud there. Attach the large terminal end there with a washer and nut over it tightened securely. **Special note for Comanche owners: Make your jumper wire 12” long and attach it on the driver’s side kick panel close to the fusebox on the 8mm stud.** Revised 11-29-2011

Do as Don suggests and don't look back.

Which Jeep? If it's the 90, I would suspect the NSS. If the 88, I would suspect the reverse light switch on the trans. But wait!! Just thought of this. Only on my 2nd cup of coffee. The 7.5 amp "trans" fuse in the fusebox has to be good in order for the reverse lights to work.

Your what is exposed? FWIW, all of my current write-ups are in the link sown below in my signature.

Not been my experience in 25 years of working on these Jeeps. Sometimes we found dead O2 sensors only because it showed on the DRB tester that way and nobody had complained of a driveability/idling issue. But, there's always something new. Couldn't hurt for the OP to check/change his O2 sensor but I've never seen one choke out a motor on it's own. There were always other contributing factors. Also, your friends Jeep was not a stock installation and other factors could have affected it. Go unplug your O2 sensor and drive around for a while. Bet it doesn't stall. Idle may be a tad low or maybe rough......

O2 being bad can cause open loop, but that's not all that rich, especially to cause flooding. It's a predetermined program in the ECU. Half the guys on this forum with a rEnix Jeep probably have bad/lazy O2 sensors and don't know it. MAP getting low vacuum can cause lots of flooding though. Causes ov overly rich mixture in order of highest degree and severity. 1-MAP 2-CTS 3-IAT 4 O2 sensor

Cruiser’s Trans Plug Refreshing Over near the transmission dipstick tube are 2 rather large connectors. One is black and the other gray. These 2 connectors carry all the info between TPS, TCU, NSS, speed sensor, and transmission solenoids. Unplug each one, visually inspect for corrosion or bent pins, spray them out with electrical contact cleaner and plug them back in. Additionally, if your Jeep is an 87 to 90 Renix, it’s always a good idea to reach up under the glovebox area and unplug the connector to the TCU and spray it out along with the receptacle of the TCU. While you’re there, find the fuse right in that area for the TCU. Remove it and spray out it’s receptacle and clean any corrosion from the fuse. Revised 9-10-2012 Don't forget to do this while you're poking your noggin under the hood:

795 bulbs also work in the stock sockets. Halogen bulb on an 1156 base.

No. The 86 is a throttle body fuel injection system where the 4.0 is a multi-port system. What's your issue?

Torque converter unlocking?

Test the TPS on the "trans" side 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 body and 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

Used $35 at U-Pull-It. Bet that's not it though......

So you set it according to the write-up? I wonder if anyone turned the Torx air bleed screw on the driver's side of the TB. Is your exposed or does it have the plug over it?

CPS works totally independent of anything else. It generates it's own signal. The mechanic is full of it and has no frickin' clue.

Not to mention winter blend fuels cause a fuel mileage loss.

No. It won't. Make sure all your intake manifold to head bolts are tight. Wiggle each injector plug at idle and see if it changes. 750 idle in gear with an auto trans in D or in Neutral?

I don't understand. Punctuation?