cautionmts

yeah i dont know how to erase the others..sorry

johnwdillon

I seem to be having a similar issue.. but with some variations.

its a 91 with the 4.o and and it idles/runs fine when in park, but when you shift out of park into drive, and put your foot on the break, it feels like it is missing.. it will run for 2 or 3 seconds then sputter the 2 or 3 more then sputter..

or when you are riding along, then put your foot on the break, and come to a stop, then it seems like it is skipping too.

I had in mind a possible vacuum leak somewhere, but I have not been able to locate it. maybe the IAC is dirty? Haven't checked that. My air filter is old, and needs replacing anyways, so i will pick one of those up, is it possible that a dirty air filter can blow a mass airflow sensor or something? That went out in the f150 my brother has, and it ran like total crap all the time though until it was replaced.. not just at idle.

any help would be awesome

hope you guys find a solution.

cruiser54

We have no mass air flow sensors on our Jeeps. Sounds like you need to do some maintenance including a throttle body and IAC cleaning. When was the last tune-up done? Ever pulled a spark plug and looked at it?

4wheeldrivenewbie

The cps will sometimes cause this i replaced my sensor with a new one and i seem to get less stalling.

However im using a cheapo one not the slotted on you could prolly get even better results with the dealer part who knows.

cruiser54

CPS is not likely a culprit in stalling. More common to cause a crank-no-start.

johnwdillon

tune up less than 6 months ago, new plugs, wires, cap rotor, air filter, replaced the valve cover gasket because it was leaking, and replaced the rear main due to leaking. this jeep had a no start problem at one point, but pulling the idle control wire and wiping it off and plugging it back in it never happened again.

took it to a shop to have this diagnosed, and all they did was replace my distributor cap. they said it was dirty with oil in it.


I can pull a plug and take a look at it, but I dont think that will be the cause of this.

cruiser54

Just making sure the basics are covered.

chicago

i had the same problem with my jeep. once it got warm it sputtered and eventually died out but driving was fine. i cleaned my idle air control and it didnt do anything. i cleaned my battery connections and it ran fine ever since. no more sputtering.

johnwdillon

brand new battery with new wires too.

I'm getting frustrated with it.
I hate the feeling that the jeep wont get me home. I love driving it.. but seriously.
I had a problem with my TPS also.. I never replaced it, I just took it out and cleaned it.. could that cause it? maybe it isnt holding the idle high enough? it seems to idle right around 500-800 but when it skips it drops to about 350-500

cruiser54

OF COURSE that could cause it!!!

johnwdillon

I know that sounded like a stupid question, but when I have had a problem with the TPS before, it caused it to just not run at all.. it would start up.. go to a high idle, then drop to like 250 then die out.. After taking it out, cleaning it and putting it back it, it ran fine..I didn't think it would be that cut and dry.

but I will check it out.
I have an appointment with a shop tomorrow to get the cooling system replaced, I will have them look at that as well.

cruiser54

Actually, it's extremely rare if not unheard of that a TPS causes a no-start.

I'd replace it and set it properly myself unless you just wanna spend money at a shop.

johnwdillon

Like I said.. it would start.. but it just wouldn't idle.. it would just die out.

I have no idea how to set it. And its going to be at the shop for the radiator anyways.. They are only 75 bucks or something so I can imagine it being to bad. maybe 125-150.

do you know how to reset them? maybe I can do it my self after all..

cruiser54

RENIX TPS ADJUSTMENT
Before attempting to adjust your TPS be sure the throttle body has been recently cleaned. It's especially important that the edges of the throttle butterfly are free of any carbon build-up.
IMPORTANT NOTE: With the Key OFF, and using the positive (red) lead of your ohmmeter, probe the B terminal of the flat 3 wire connector of the TPS. The letters are embossed on the connector itself. Touch the black lead of your meter to the negative battery post. Wiggle the wiring harness where it parallels the valve cover and also over near the MAP sensor on the firewall. If you see more than 1 ohm of resistance, or fluctuation in your ohms reading, some modifications to the sensor ground harness will be necessary. The harness repair must be performed before proceeding. I can provide an instruction sheet for that if needed.
MANUAL TRANSMISSION:
RENIX manual transmission equipped XJs have only a flat three-wire TPS mounted on the throttle bodyand it provides data input to the ECU. It has three wires in the connector and they're clearly embossed with the letters A, B, and C. Wire "A" is positive. Wire "B" is ground. Key ON, measure voltage from "A" positive to "B" ground by back-probing the connectors. Note the voltage reading--this is your REFERENCE voltage. Key ON, back-probe the connector at wires "B" and "C". Measure the voltage. This is your OUTPUT voltage. Your OUTPUT voltage needs to be seventeen percent of your REFERENCE voltage. For example: 4.82 volts X .17=.82 volts. Loosen both T-20 Torx screws attaching the TPS to the throttle body and rotate the TPS until you
have achieved your desired output voltage. Tighten the screws carefully while watching to see that your output voltage remains where it is supposed to be. If you can't achieve the correct output voltage, replace the TPS and start over.
Sometimes, after adjusting your TPS the way outlined above, you may experience a high idle upon starting. If that happens, shut the engine off and reconnect your probes to B and C. Start the engine and while watching your meter, turn the TPS clockwise until the idle drops to normal and then rotate it back counterclockwise to your desired output voltage.
AUTOMATIC TRANSMISSION: RENIX automatic transmission equipped XJs have a TPS with two connectors. There is a flat three-wire connector, same as the manual transmission vehicles have, and it is tested the same as the manual transmission equipped vehicles, as outlined above—FOR ALL ENGINE MANAGEMENT RELATED ISSUES.
However, the automatic TPS also has a square four-wire connector, clearly embossed with the letters A,B,C, and D. It only uses three wires and provides information to the Transmission Control Module. THIS SQUARE FOUR WIRE CONNECTOR IS USED FOR TRANSMISSION/SHIFTING RELATED ISSUES ONLY. Key ON, measure voltage between "A" positive and "D" ground. Note the voltage. This is your REFERENCE voltage. Back-probe the connector at wires "B" and "D". Measure the voltage. This is your OUTPUT voltage. Your OUTPUT voltage needs to be eighty-three percent of your REFERENCE voltage. For example 4.8 volts X .83=3.98 volts. Adjust the TPS until you have achieved this percentage. If you can't, replace the TPS and start over. So, if you have an automatic equipped XJ your TPS has two sides--one side feeds the ECU, and the other side feeds the TCU.
FOR AUTOMATIC TRANSMISSION RELATED ISSUES: Check the square four-wire connector side of the TPS.
If you have ENGINE ISSUES check the flat three-wire connector side of the TPS.
For those with a MANUAL TRANSMISSION--the TPS for the manual transmission XJs is stupid expensive. You can substitute the automatic transmission TPS which is reasonably priced.
Revised 09-22-2012

johnwdillon

I suppose it is possible that it was something else causing it to not start, but after I pulled the TPS plug and cleaned it and put it back, it started right up.. May have just been a coincidence.


I am pretty fresh to jeeps,(and mechanics in any way) so I am not trying to sound like a dumb_____ here.. I just need to learn more about it I guess .
but that's why I am here