halmotors

I know, I know, you probably see a hundred thousand of these threads. I did some searching, both here and on the rest of the intarwebz, and I couldn't quite find the answer I was looking for.

I've noticed my transmission will seem to hold on to 1st gear until it reaches 3500rpm, at which point it will shift into 2nd. Researching the issue a little pointed me towards the TPS as either needing adjustment, or replacement. Well, the few articles I found have some...discrepancies, at least in regards to the appearance and location of my TPS.

For a little information, I have a 1995 Cherokee Country, with the 4.0HO engine, and the AW4 transmission.

The diagrams and photos of the TPS I've been able to find have portrayed it as being on the front of the throttle body; mine is on the rear. As well, they show the TPS as having two adjustment screws on the body; mine does not have these screws, instead having two screws to secure the entire module to the throttle body. Also, they show the plug for the TPS as having a square setup where the wires enter the plug, whereas mine has them set up in a line, with no markings as to which wire is which (A B C D).

I snapped a few photos for reference; I want to make absolutely sure I'm looking at the right thing in the engine bay. The front of the engine bay is to the left side of the photos.

This is the TPS, if I'm not mistaken:


This is the order of wires, to my knowledge:


And these are the only thing I can see that could be considered 'adjusting screws'.


Sorry for the lack of clarity in the photos; it was getting dark here, and that's the best my cell camera could do without a flash. Am I looking at the wrong thing here? Please, don't hesitate to tell me if I'm completely off-base with this.

Also, I only have a multimeter with which to test the TPS; all the walkthroughs I've seen have recommended using a voltmeter. Can a multimeter be used in place of a voltmeter? When it comes to mechanical things, I'm pretty good, but electrical work confuzzles me sometimes.

Jamie57

Can't answer your TPS question but a MULTI meter is just that. It will test a multitude of things
Voltage (AC/DC)
Amperage (Very low)
Reisitance (Ohms)
You've got the right tool for the job.

93jeepthing

the sensor you are pointing to is the idle air control valve. The TPS is the one right below it in the picture. You can tell because it is directly in line with the throttle valve. the throttle cable and lever on one side of the throttle body and the on the other. I just replaced mine about 5 minutes ago due to a transmission shifting issue, it didn't seem to help any, although they do seem to commonly go bad. As for the adjusting screws, i didnt see any way to adjust it when i put it on either.

-Brian

halmotors

Are you sure? That plug only has three wires heading into it, whereas all the descriptions I've seen show the TPS as having four wires.

And thank you for the info, Jamie. What should I set my multimeter to? ACV 10v?

Abovetimberline

Mine is an 89 and did the same thing,tps change cured the issuse. The voltage on mine was .5 t0 4.5 approximatley.

dirtbiker117

Manual or automatic? Manual would only have three wires going to the TPS I believe. I'm pretty sure that all HO engines (91 and later) have a plug and play TPS - no adjustment.

You've probably already seen this if you've done some research on your problem, but have you adjusted the tranny kick-down cable?

halmotors

I haven't touched it yet, no. And it's an automatic transmission.

SeriousOffroad

Yep, that's the IAC. TPS is on the front of the throttlebody.

SeriousOffroad

Oh, go look in your inbox.

SeriousOffroad

What hell, Here ya go...
http://www.greatlakesxj.com/tech/TPS.html

SeriousOffroad

Sent another pm

halmotors

Thanks, that helps a lot. I'll definitely check it out when I've got light to work with tomorrow.

93jeepthing

i am positive. when i changed it yesterday i also took the IAC valve out (the one you pointed to) to clean it. TPS is the one next to it.

a good way to check it is right at the computer, under the passenger dash. turn the key on, engine off and put the neg lead on pin d7 and the positive lead on pin d2 and set the multimeter to volts dc. push the pedal down and the voltage will change. 4.5 volts at throttle closed, .5 at wide open throttle. look for "flat spots" as you push the pedal down- spots where you are pushing the pedal down slowly but the voltage isnt changing. also look for sharp jumps in voltage. You can also check the TPS ground by putting the the positive lead on pin d3. It should be less than .1 volts. by testing it at the computer you not only verify proper tps operation, but you also verify the wiring to the computer. Good luck.

-Brian