Have you indexed your distributor? My 89 comanche had a intermittent miss and bogged when I let off the throttle.... Only happened when it was cooler outside... Maybe your distributor is running out of timing adjustment?

 

That's a TPS issue or a sensor ground issue.

 

Ain't no MAYBE about it. Ground refreshing also. C101 cleaning if it applies to you. Connector and relay refreshing for sure.

 

My cherokee is having the problems. It's gotten worse as the weather warms up. Does it matter that it has a 180 t stat this summer?

 

Ha. I just took a good look at some of my grounds, the negative battery cable insulation is almost gone and the cable has seen better days. I'll let you guys know what happens when I replace it. Thanks for the tip.
Oh and that 180 T stat should be fine for summer, going down the highway should run nice and cool but will still probably get to 210 Ish in stop and go stuff.

 

That's the same reason I replaced my ground cable. It fell apart when I took it out. It sure does stay cool at highway speeds. Only hits 210 while wheeling and traffic.

 

I got around to replacing that ground cable today, started the Jeep, got it warm then restarted it probably a dozen times and didn't have a hanging idle even once. Fingers crossed that was it. Thanks for the help.

 

You're ****ting us. Ground cables make that much difference? LOL. Whooda thunk it?

 

Lol. In renix era jeeps if the ground looks old just replace it! Also replace the undersized ground between block and body when you do so.

 

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

 

Hey! give me a break, i've only had this thing about a month and never had a car that has problems with grounds. lol

 

When I bought my comanche I replaced and upgraded the grounds before I even got it running. I had it running in 2 weeks of buying it.

 

No slack for you. Get your butt in gear and do the complete refreshing. No shortcuts. When you're done with that, click on the "pink link" in my signature and contimue on with #s 2, 3,
4, and 5.

This is your initiation into the CF Renix world. LOL....

 

formula ooh ha ha!

 

Replace the fuel pump im telling you I have replaced and refreshed my grounds

was told it was the tps and or idle air control or vaccum or bad grounds had a hesitation aswell but I was still told to check the same things for the bouncing up and down idle none of that fixed the up and down idle.

I had bad egr and took it out and blocked the hole the car ran way better but the up and down idle never went away. as for the throttle body screw that dident effect the up and down idle.

As I installed one on mine from the bone yard that had never been touched you could tell no one had turned it. and idle was the same as with the old one.

My bet is on fuel pump check valve. Also if you notice any wet spots on any injector id replace those aswell not worth wasting money on just O-rings.

There is a write up on injectors somewhere 96 dodge neon ford mustang injectors from certain years will work and spray better ive read