badlands1

I switched out the clutch on the a/c compressor last night and I took out the battery,e-fan and the idler pulley to make the job easy.I put everything back together and my compressor is much queiter.But I go to start it up this morning and the darn thing runs like crap.What did I do?I want to state that nothing was wrong with it prior to this.Its sputtering under throttle either in gear or park.I push the throttle and it sputters and backfires.Could maybe the belt be to tight?I havent a clue...Its making me nervous this is my only vehicle.Could I have got something wet ie coil,pulleys ect. 1989 jeep xj 4.0/aw4
Thanks and much apreciated
Nate

hypersthenos

Welcome! A recurring theme with Renix era jeeps is the faulty ground portion of the electrical system. Much of the work under the hood can adversely affect this problem but the correction is basic. Just do a search of this forum for "Renix negative ground" & you'll find all that you need. Here's a summary of the potential problem/s: The negative battery cable bolts to the engine block at the stud that holds the oil dipstick bracket in place. While doing work on the engine this is an arae that, if disturbed, can cause a problem. Another area is the ground strap from the cylinder head to the firewall. Both are simple fixes. Though this may not solve the problem you currently have it will prevent problems later that are all but guaranteed to occur and withour correcting them you are not eliminating the most likely cause of your currentl issue.

badlands1

Thanks for the welcome Ive been in the shadows here for awhile now just havnt become a member.Ive been on the jeepforum and pirate for years.This forum seems abit more constructive.Thanks for the info Ill try that and go from there.The other thing Im going to look around for is vacuum lines being disconnected.This is my first renix 4.0.And I have herd there interesting electrical issues.It just happened over night and was so happy with my new clutch then this happens.

cruiser54

Here ya go. Also be sure you dind't mess up the plastic line and hose from the throttle body to the MAP sensor located on the firewall.
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

The Rooster

i was also thinking round also..

cruiser54

Round, around, or ground?

The Rooster

ground...

DFlintstone

Darn, Cruiser beat me to it. If you even breathe on that tube from the MAP, (there up on the firewall), forward to the rubber plug in the throttle body, it will pop to pieces. Then your Jeep will run like doogy, if at all.

Also...those wires going down in front by the PS pump. Mine grounded for a year or so on the edge of the heat shield and it would dog/sputter/fire back out the airbox. (made life rough for the mice living in there) You might check yours are OK after tensioning the belt. (02, temp, knock sensors down there)

https://www.cherokeeforum.com/f51/he...ix-links-1397/

cruiser54

Never hurts to inspect the harness that runs along the valve cover. They are prone to chafing up front as Flintstone's did, but the 87 and 88 models had problems with chafing back near the firewall/rear of head area.

jvanhare

I fixed my Renix problem, gave it to my son and got my wife a '97.

cruiser54

Don't delude yourself, It, and your son, will be back to haunt you.

badlands1

Thank you so much guys I never get responds on the jeepforum.Ive been on there for the last 5 years and learned alot from pirate and there but just not much of people responding to questions.Thanks again Im going to go work on her.

The Rooster

np... the Renix 4.0 is awesome and runs 4ever.. just takes a little time and ground cleaning..... if you have anymore questions just ask..

jvanhare

Ha, true enough. I went and visited him and it last night. Installed an under cabinet microwave.
Mine used to stall when I let off the gas coming off the freeway, and idle like crap...it was the EGR valve. I cut the hose in the middle and plugged both ends with "test screws", runs better than new. The Renix system is very simple and vacuum lines are definitely worth checking thoroughly in addition to the well known grounding problem.

badlands1

It was the ground guys thank you very much.Good as new.And I did the upgraded gauge wires for all the grounds why I was at it including the dinky braided strap.