Ok so ive had everything Cruiser said checked. The grounds no resistance not dirty all are getting good voltage on the Dipstick.

If we really wanted to we could just run all those grounds to the negative battery no oil no nothing but why would we. They all checked out.

We even replaced the coolant sensor the one on the block checked fuel pressure its all where it needs to be.

I would imagine the computer needs sometime to reprogram itself so maybe my tach is bouncing every so often at idle because the computer is still searching for idle idk.

I ran it for about 5 mins and i pressed the gas pedal once thing sounded like the hesitation then when i let off the pedal thing shot right down on the tac needle and almost died then came back.

Ive replaced the vaccum harnest. The pcv hose air filter plugs wires.

map sensor tps iac the whole throttlebody all 3 coolant sensors the one for gauge the one for the fan and the one on the block.

replaced my fuel filter gave it an oil change last year keep in mind i dont drive more then to a store with it.

Noticed some blow by in my air box half the filter was blacked up.


So everything that cruiser told me a few weeks ago has been checked on and i just dont think its doing anything different.

but everyother sensor in the car is just about brand new so we figured the coolant temp on was important and one of the last ones that was old so we changed it.

Any other ideas would be great as im still stumped. Once i reregister it ill be able to drive it around and really see how its gonna run but i mean i dident do anything really sept change one sensor.

 

Did you do this?
Cruiser’s Renix Sensor Ground Test
　
This sensor ground circuit affects the CTS, TPS, IAT, MAP, ECU and diagnostic connector grounds. It’s very important and not something to overlook in diagnosing your Renix Jeep as it is common for the harnesses to have poor crimps causing poor grounds. If any or all of the sensors do not have a good ground, the signal the ECU receives from these sensors is inaccurate.
Set your meter to measure Ohms. Be sure the key is in the OFF position. 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 runs parallel to the valve cover and also near the MAP sensor mounted on the firewall. If you have an 87 or 88 with the C101 connector mounted on the firewall above the brake booster, wiggle it, too.
You want to see as close to 0 ohms of resistance as possible. And when wiggling the harnesses/connectors the resistance value should stay low. If there is a variance in the values when wiggling the wires, you have a poor crimp/connection in the wiring harness or a poor ground at the engine dipstick tube stud. On 87 and 88 models, you could have a poor connection at the C101 connector as well.
Revised 06/12/2012

 

Ill give that some thought and check them if we havent already

 

Still having a problem While my idle rpms aint bouncing up then down every so often it seems steady.

I still get whats called a hesitation sounds like its breaking up when i hit the pedal then when i let off the idle drops almost all the way down motor gets rough can feel it and almost stalls but somehow shoots back up to normal idle.

The pedal is right there sometimes the motor revs right up but the rpms still drop low then level off.

This is just while in park charging the battery running it.

 

Takes 22 seconds to do and could very well be part of your problem. What are you waiting for?

 

I told u as before my grounds are not bad there all clean and working you have asked me in atleast 4 different posts to check grounds refresh grounds change grounds ive stated ive done that.

you stated they could be dirty ive checked em ive even replaced the dipstick ground.

Youve stated resistance im getting none there reading the right voltage.

 

Now wait a minute. How can a sensor ground circuit get the right voltage?

You've done this?
Cruiser’s Renix Sensor Ground Test
　
This sensor ground circuit affects the CTS, TPS, IAT, MAP, ECU and diagnostic connector grounds. It’s very important and not something to overlook in diagnosing your Renix Jeep as it is common for the harnesses to have poor crimps causing poor grounds. If any or all of the sensors do not have a good ground, the signal the ECU receives from these sensors is inaccurate.
Set your meter to measure Ohms. Be sure the key is in the OFF position. 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 runs parallel to the valve cover and also near the MAP sensor mounted on the firewall. If you have an 87 or 88 with the C101 connector mounted on the firewall above the brake booster, wiggle it, too.
You want to see as close to 0 ohms of resistance as possible. And when wiggling the harnesses/connectors the resistance value should stay low. If there is a variance in the values when wiggling the wires, you have a poor crimp/connection in the wiring harness or a poor ground at the engine dipstick tube stud. On 87 and 88 models, you could have a poor connection at the C101 connector as well.
Revised 06/12/2012

 

my dad checked the grounds and he tested them with a meter got a normal amount of resistance set the tps it was reading at 4.95v.

Just had some work done on it today swapped out the bosch platinum plugs and went with a champion truck plug copper as people mentioned.

I swapped out the map sensor with another i got out of a 90 jeep.

If you remeber before the jeep would go from 900-850 down to say 400 every 30 seconds during cold idle.

I also noticed when i pressed down the pedal the jeep made a couple of putts

If you remeber before sometimes id be in idle park and id hit the gas and the throttle was right there other times you would hit the gas and when u let off the tach would shoot down to almost 0 sound like it want to stall then bounce back up to normal.

Havent drrove it yet anywhere but the hesitation might still be there.

When i try to backup if i just touch the gas it will stall usaully.

I picked up a new cps maybe that will help i havent installed that yet but my idle is at about 600 rpm and will drop to about 400 every so often then bounce back up

 

4.95 is just the input voltage to the TPS. The TPS needs to be adjusted.


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

 

oh yea we loosened it up and moved it around while checking it the voltage was adjusted accordingly checked it from the battery ground and checked the ohms everything appeared normal.

I just dumped 12 gallons in it and 3 qaurters of a bottle of seafoam in it. If we have to we can just bypass all the dipstick grounds and wire everything to the neg battery run directly to the computer bypass all the old plugs if need be only other thing that hasnt been replaced other thenthe cps is the o2 sensor

 

So you got .84 volts between B and C on the flat connector?

 

We got .80v. and as of today we tryed to set the timing i know the distributer is not adjustable but you can still turn the flywheel and stick a screw driver in number one and and line it up checked the compression and it was there still dident change nothing.

Car still spudders and is doggy from 35 to 45mph. Gonna put in the cps next however ive herd that if the cps isnt from napa or the dealer its junk dont buy it???.

also there is a resistor on the fuel pump and maybe a knock sensor???

Its wierd cuz sometimes you hit the pedal and it goes no spuddering hesistation other times hesistation and spudding.

If i just touch the gas and it starts spuddering and i hold it there it will spudder all the way down the road till i push it down more or either let off.

However if it is spuddering and hesistating and you let off it will usaully die.

Also ive noticed 900rpm then a drop down to 650 every so many seconds. say 30 seconds of 900 rpm at cold then bounces down to 650 then about 15 seconds later back up to 900.

The tac bounces most of the time before it stops. If you give it gas quick and take off say you get the tach up to 1500 rpm it will bounce slightly before it stops if you let off the gas when the tach drops it will bounce slightly before it stops at the number

 

From the color of the spark plugs it appear its running to lean

 

Fuel pressure is 31 ish at idle, and toward 40 with the vac line off the regulator I hear. Two important temp sensors, the IAT on the manifold, and the CTS down below, both will send "make it leaner" signals to the ECU with less resistance there. If they were unplugged, and there wires arent shorting/touching that could be ruled out. There's a chart here>>> https://www.cherokeeforum.com/f51/he...ix-links-1397/

I had a fluctuating idle, it was my 02 sensor...If you don't know the history of yours....it's crucial for mileage, you might want to just stick an NTK in there...https://www.cherokeeforum.com/f2/ren...ce-rms-133153/

 

Well now we've got the dizzy twisted around, the TPS set incorrectly, yada yada..............