cruiser54

.830 is the setting for the engine side...........

Clarify this. Did you refresh the grounds at the engine dipstick tube stud and both trans plug connectors?

Black89

I just ran out on my break here at work and measured it again. Input voltage is at 4.68 output is 3.91 so that has me at 3.24 instead of 3.98. Looks like I need to clean the grounds first to see if I can get up or @ to 5 volts on the input side and then readjust the TPS accordingly. Also thinking my meter at home may be off. Gonna bring my work one home tonight with me.

Black89

Black89

I was able to get it up to 3.8 volts here at work but the crappy driver I have here won't allow me to get at the bottom torx screw. I'll have to get the fine tuning done when I get home later tonight. At least with it closer now maybe it will help a bit.

Black89

cruiser54

TPS may be FUBAR. Be prepared to replace it.

Do the grounds and connector refreshing FIRST.

Black89

The TPS is only a week old. I think the adjustment write up I found on-line was wrong or I read it wrong. I was reading through the square plug the whole time but it said to divide the numbers not to multiply like your info states. This one should adjust out but I still want to clean my grounds. It's the only thing under the hood that I haven't had time to do yet.

Black89

cruiser54

Super important to refresh the grounds and set the TPS properly. Keep us informed.

Black89

My drive home last night and the one to work were both much better but not quite there yet. Saturday morning the grounds are getting fixed and then a little re tune is in line for the TPS. I'm on the right though.

Black89

cruiser54

See what grounds at the dipstick tube stud?



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

Black89

OK so the rain stopped tonight long enough for me to mess with the grounds. I added an 8 AWG ground from the block to the fire wall, another 8 AWG ground from the negative side of the battery to the core support, Cleaned the ribbon one on the back of the head and the mount spot on the fire wall, (same spot I hook my 8 AWG one to), Pulled the dipstick grounds (four total plus the negative from the battery) cleaned them with the dremel and put back on.

So back to the TPS I went. I can still only muster 4.5 to 4.6 volts on the input side and if I fine tune the TPS I can only muster out the same which leaves me at 3.81 volts. Still shy off the 3.98 needed.

So what's the next step in getting the input voltage up? Where is the power for this coming from? I have pulled all the under hood relays out and cleaned them.

Black89

cruiser54

There is no "needed" figure. It's a percentage of the input voltage. Set it to that and go for it.

Black89

Ok I think I got it. Just need to test drive to make sure but I got 4.67 volts this morning on the input side multiplied that by .83 and set the TPS at 3.87 volts. I had the meter hooked up while I tightened the screws back down to ensure the setting didn't change. Fingers are crossed and I'm hoping this works. Cruiser thanks for the wealth of knowledge and your help. Your one of the reasons I'm here on this forum.

Black89

cruiser54

Well, you did a bang-up job of adjusting it. Keep us informed.

67 GMC

It wouldn't hurt to move the wires around on the AW4 transmission itself to check for frayed wires that could be grounding when the transmission heats up. I had an issue with the speed sensor that once warmed up, it would report a 0 speed and the trans would shift to 1st. I couldn't replace the speed sensor but moving the wiring around while trying to remove the sensor cleared up the issue (for now anyway).

I assume you've done the TV cable adjustment as well. There's a few write-ups on that on this site as well. That wouldn't be the source of your issue but I couldn't get my Jeep to kick down when the pedal was floored and the cable adjustment fixed that.

These vehicles are getting long in the tooth. Some components that were meant to last the life of the vehicle start to fail since we're way past that point with a 20+ year old Jeep! Some components don't seem to last long at all (like TPS / CPS sensors). Not sure if this is poor quality on non-Jeep parts or just design flaws.

cruiser54

Do the sensor ground test.

Black89

I did a short run around the neighborhood yesterday and it seems to be working fine at this point. It's a 15 mile drive to get to an area out of the mountains here where I can up to 55 MPH so that test will have to wait until my drive to work on Monday morning. I did adjust the TV cable on Friday. It was about 3 clicks out and after the reset it's now one click out which has made the uphill shifting tons better. I have lots of time today so for the hell of it I will check the wires at the trannny and will also do the sensor ground test as well just to be sure. It's kinda funny because after all this work this little thing will actually do a burn out now on my cement driveway. It wouldn't do it before. It's got a neighbor of mine wondering whats going on with his 98' Grand. His 4.0 is a dog compared to my little 89'. LOL

I'll report back after I work on it today......


Black89