cruiser54

The ground strap at the back of the head is even more critical on the 4 banger for some reason. Also, a new engine has fresh paint on it..... 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, failed emission tests, and wasted money replacing components unnecessarily. 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. For those of us with Comanches, it’s very important to remove the driver’s side taillamp assembly to access the ground for the fuel pump. Remove the screw holding the black ground wire. Scrape the paint from the body and corrosion from the wire terminal. Reattach securely. 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 03-04-2013

Those vacuum hoses near the tB can cause all sorts of issues.

Extremely well stated.

VC mod helps keep oil from being sucked into the air filter. The CPS advance mod fools the eCU and you get more advance. Do the ground refreshing, connector/relay refreshing, and sensor ground tests now and we'll go from there.

Just look up under the passenger side dash. Move the slider control. See the cable and lever moving? Is it closing all the way?

Check the fuel pressure. Also, since it's a REnix Jeep, you need to do some groundwork. Click on the link in my signature.

9 is the second digit of 89 and 02 is February. What's the mfg date of the truck?

I suggest unplugging EVERY electrical connection in the engine bay you can find, whether engine related or not, and spraying it out with a good electronics cleaner, visually inspecting the terminals making sure they haven’t retracted into the plastic holder, and then plugging it back together. There’s a critical 10-pin connector for the front lighting system located in front of the air cleaner and behind the left headlight assembly. Don’t miss that one. Also be sure that the connectors to the ballast resistor mounted near the air cleaner housing are clean and tight. ALL of the relays should be removed, the terminals wire-brushed until shiny, and the receptacles sprayed out with contact cleaner. Then plug them back in. I do this on every Renix Jeep I purchase or work on for someone else. Revised 07/23/2012

Renix CPS Testing and Adjusting Renix CPSs have to put out a strong enough signal to the ECU so that it will provide spark. Most tests for the CPS suggest checking it for an ohms value. This is unreliable and can cause some wasted time and aggravation in your diagnosis of a no-start issue as the CPS will test good when in fact it is bad. The problem with the ohms test is you can have the correct amount of resistance through the CPS but it isn’t generating enough voltage to trigger the ECU to provide spark. Unplug the harness connector from the CPS. Using your voltmeter set on AC volts and probing both wires in the connector going to the CPS, crank the engine over. It won’t start with the CPS disconnected. You should get a reading of .5 AC volts. If you are down in the .35 AC volts range or lower on your meter reading, you can have intermittent crank/no-start conditions from your Renix Jeep. Some NEW CPSs (from the big box parts stores) have registered only .2 AC volts while reading the proper resistance!! That’s a definite no-start condition. Best to buy your CPS from Napa or the dealer. Sometimes on a manual transmission equipped Renix Jeep there is an accumulation of debris on the tip of the CPS. It’s worn off clutch material and since the CPS is a magnet, the metal sticks to the tip of the CPS causing a reduced voltage signal. You MAY get by with cleaning the tip of the CPS off. A little trick for increasing the output of your CPS is to drill out the upper mounting hole to 3/8” from the stock 5/16”, or slot it so the CPS bracket rests on the bell housing when pushed down. Then, when mounting it, hold the CPS down as close to the flywheel as you can while tightening the bolts. Revised 01-26-2013

Renix Jeep ICU/Coil contact refreshing The contacts between the coil and the ICU on your Renix Jeep can become corroded and loose causing a complete or intermittent no-start condition. I recommend the following procedure as a maintenance precaution to insure this is eliminated as a possible cause now and in the future. The coil is attached to the ICU by two T20 Torx bolts. Remove these two bolts and lift the coil up off the ICU. You will see 2 pins and 2 sets of contacts. Clean both the pins and springy contact pieces with a good electronics cleaner and some fine sandpaper. Squeeze the springy contacts closer together with some needlenose pliers. Bolt the coil back on to the ICU. While you’re right there, unplug the connectors from the ICU and inspect the pins in the harness connector. Make sure the pins are not retracted into the connector. Spray out the connector and the receptacle of the ICU with the same good electronics cleaner you used earlier. I feel this procedure should be performed at least once in the lifetime of a Renix Jeep. Revised 04-04-2013

Renix Jeep C101 Connector Refreshing The C101 connector on 1987 and 1988 Renix Jeeps was a source of electrical resistance when the vehicles were new. So much so that the factory eliminated this connector in the 1989 and 1990 models. The factory recommended cleaning this connector to insure the proper voltage and ground signals between the ECU and the fuel injection sensors. We can only imagine how this connector has become a larger source of voltage loss and increased resistance over a period of almost 25 years. The C101 connector needs to be cleaned at least once in the lifetime of your vehicle. Chances are it’s never been done before. Almost every critical signal between the engine sensors, injectors, ECU, and some to the TCU, travel this path through the C101 connector. The C101 connector is located on the driver’s side firewall above and behind the brake booster. It is held together with a single bolt in it’s center. To get the connectors apart, simply remove the ¼” bolt and pull the halves apart. You will find the connector is packed with a black tar like substance which has hardened over time.Take a pocket screwdriver or the like and scrape out all the tar crap you can. Follow up by spraying out both connector halves with brake cleaner and then swabbing out the remainder of the tar. Repeat this procedure until the tar is totally removed. This may require 3 or more repetitions. Wipe out the connectors after spraying with a soft cloth. If you have a small pick or dental tool, tweak the female connectors on the one side so they grab the pins on the opposite side a bit tighter before bolting both halves back together. Revised 03-02-2013

Can't just LOOK at the grounds. The only electricity you're likely to ever see is lightning. C101 has a bolt in the center. You looking at the right thing? 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, failed emission tests, and wasted money replacing components unnecessarily. 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. For those of us with Comanches, it’s very important to remove the driver’s side taillamp assembly to access the ground for the fuel pump. Remove the screw holding the black ground wire. Scrape the paint from the body and corrosion from the wire terminal. Reattach securely. 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 03-04-2013

Renix will run fine with the stator disconnected. You hit a bump? CPS wires on the manifold and burned? Did you test the CPS? Ever refreshed the grounds or c101 connector?

Correct. No good.

so it runs on high but no other speed?

The AW4 uses the same type of signal regardless. The difference in HO vs Renix as far as TPS is that the Renix engine side TPS works backwards from all the others. Using my instructions, test the trans side of the TPS. Then, use an analog meter and sweep the throttle through it's range and see if the upper half of your TPS is dropping out so to speak.

See if they are binding and/or loose. What happens if you try to move them maually?

Thanks for the update. Good old vacuum gauges. My son rented a U-Haul van a week ago. Had a vacuum gauge right on the A-pillar. Was not factory, but from U-Haul.

there was only one blade that went bad, so i cleaned it up and it looks as good as new. Good and tight on the new switch? If so, you're good to go.

Not rude. Factual.

Dealer only. Don't have the number. Napa doesn't have it or I woulda included it in the first post. I did something totally different on my 4.0s anyway. Never liked that funky fitting at the TB. Moved my IATs to the air box. Tapped and plugged the hole in the TB. Threaded a vacuum nipple into the open IAT hole in the intake manifold. Took some plastic pipe left over from changing vacuum harnesses and bent it after heating it with a hair drier so it was routed properly. That said, and being a complicated solution, you can get the plastic line out of the funky fitting. It's only glued in and the glue isn't wirth a hoot now anyway. Remember this though. No matter what you do, make sure that vacuum line, and hard plastic is preferred, cascades down to the vacuum source with no low spots.

Poke your head under the dash and move the controls with the engine running. You'll see little silver cannisters with vacuum lines on them and levers moving. Another possibility is that a rodent has built a nest in your blower motor. Easy to check. Poke your noggin up under the passenger side dash. There's an outlet that looks like a checkerboard. Through one of the holes, push the flap up and you can see the blower motor.

Renix Vacuum Harnesses The vacuum harness that attaches to the front of the valve cover and includes the grommet/fitting, and is called the front harness, is Napa part number BK 715-1367 http://www.napaonline.com/Catalog/Result.aspx?Ntt%3d715-1367%26Ntk%3dKeyword%26Nty%3d1%26Dn%3d0%26D%3d715-1367%26Dk%3d1%26Dp%3d3%26N%3d0 The vacuum harness that is closest to the air cleaner, EGR etc, and is called the rear harness, is Napa part number BK-715-1366. http://www.napaonline.com/Catalog/Result.aspx?Ntt%3d715-1366%26Ntk%3dKeyword%26Nty%3d1%26Dn%3d0%26D%3d715-1366%26Dk%3d1%26Dp%3d3%26N%3d0 The tube from the rear of the valve cover to the intake manifold is part number 715-1365. http://www.napaonline.com/Catalog/Result.aspx?Ntt%3d715-1365%26Ntk%3dKeyword%26Nty%3d1%26Dn%3d0%26D%3d715-1365%26Dk%3d1%26Dp%3d3%26N%3d0 Revised 09-11-2012

Dod you do anything with the terminal in the plug? It needs to be cleaned/tweaked/replaced as necessary or it could fail again soon.

Don't shy away from it. My understanding of “death wobble” is this. Somewhere in the vehicle, one or more components is worn beyond tolerances, and when oscillation initiates from a suspension “traumatic” event (hitting a bump or a pothole) or also when a vibration reaches a certain point and harmonic at a certain speed, it causes theother components to react. This is called the “multiplier effect”, where one component affects one or more other components as the event travels through the front end of the vehicle. Death wobble is not uncommon with the XJ. It is even more common with a lifted XJ. Finding the worn component or components is not always easy. It can sometimes be downright difficult. Sometimes it’s obvious. other times everything appears to be okay when you perform an inspection on a hoist, but getting the vehicle up in the air and going over everything with a fine tough comb is always a good first step. It is very helpful if you know exactly how to perform a comprehensive inspection of every single front end part, looking for abnormal wear and or play in that hardware. If you do not know how to do this type of inspection, pay an experienced professional to do it. Be sure to ask them if they are familiar with “death wobble”, as not all technicians are versed in this….. Check out the below link if you would like some extensive reading on “death wobble” causes and cures. From my research, Kevin (the author of this tutorial) is possibly the best in the business with tracking down root cause of death wobble. He does offer hardware for sale that can help resolve death wobble, but even if you don’t buy any parts from him, you can still get some excellent ideas on what to look at in resolving your death wobble. http://www.kevinsoffroad.com/how-to-fix-your-own-death-wobble/ Possible causes of death wobble are listed below. Isolating death wobble is a process of elimination and the root cause is not always obvious and it can often be caused by a combination of things! From my personal experience, I would first concentrate on the track bar and the control arms and associated bushings. -------------------------------------------------------- -Front tires out of balance (try swapping fronts to rear and see if symptoms change) -Tire pressure. Don’t laugh. It’s not a root cause but can exaggerate the problem. Experiment with lower tire pressure to see if it helps -Improper lug nut torque on wheels -Front alignment out of spec -Loose track bar -Worn track bar bushings -Worn track bar (check for play!!) -Bad control arms and associated bushings -Worn/damaged steering stabilizer (not generally a cause in and by itself) -Worn/damaged shocks -Worn/damaged tie rod end -Bad U Joint -Bad ball joint -Loose frame mount -Steering box loose -Bad front hub assembly Tom Walker