Idles great - wont take throttle

[Tally_XJ]

I am at my wits end on this and am trying once more to get some clue as to what is causing my problem. All of what I have done has made absolutely no difference.

I had posted about this a couple weeks ago, got some suggestions. All have been checked and implemented to no avail.

I thought I would start another new thread so that anyone who might have some advice doesn't have to wade through the other posts.

Vehicle:
1989 Cherokee 4x4
4.0 litre
RENIX computer control system
232,568 miles

Symptoms:
- Engine stalled at a traffic light. Wouldn't restart (cranked but no fire)
- Towed across the street and there I installed a new Crank Position Sensor
- Engine then started as it should, idles great but would not take any throttle without breaking up and backfiring badly.
- Seems to be a timing/spark/timing advance type issue. Also seems to be very rich mixture problem as the exhaust smells very rich.

Whats been done/checked/replaced:
- New Crank Position sensor (as mentioned above, not another one since)
- New spark plugs
- Checked fuel pressure (32psi with regulator vacuum, 39psi without vacuum)
- Fuel pressure readings are at idle as the RPM's will not go above 1200rpm
- Replaced MAP sensor
- Replaced TPS
- Replaced ignition control module and coil
- Replaced O2 sensor (used one out of known running engine)
- Checked and found no vacuum leaks anywhere
- EGR has been removed from this engine two years ago. Not the problem.
- Catalytic converter was removed one year ago. Not the problem.
- Timing chain replaced two years ago.

[PolishX]

cap, rotor and have you checked the bolt that holds the tab on the dost .

[Tally_XJ]

I do want to add that I did the three following things and these are the results:

- Unplugged MAP sensor connector. Engine immediately died.

- Unplugged MAP vacuum line. Engine RPM's went down to lower than normal idle speed.

- Moved the TPS wiper arm while at idle. Engine sputtered a bit but did not do much else.

[Tally_XJ]

cap, rotor and have you checked the bolt that holds the tab on the dost .

Cap and rotor are not that old and are high quality NAPA gold series. The inside of the cap and rotor button dont look new but are not that bad.

Distributor tab is present and is tight.

[PolishX]

still might check for a crack it is plastic . may be worth the time to pull dist and see if that gear at the bottom is tight or gnawed up ,is an 89 OBD 1?

[Tally_XJ]

Yes, it is OBD1

I am just stupified that it can run perfectly one moment, stall, and then run like absolute hell 30 minutes later.

The only things I have not done is replace the cap rotor, distributor itself and the ECU.

[PolishX]

is it throwing codes ? do you have a code reader ?

[8Mud]

Yes, it is OBD1

I am just stupified that it can run perfectly one moment, stall, and then run like absolute hell 30 minutes later.

The only things I have not done is replace the cap rotor, distributor itself and the ECU.
A few things pop into mind, do an ohm test on your CPS, when the motor is hot. Do a resistance test on the CPS wires, you will have to unplug the CPU and will need a good diagram.
Check the reference (input) voltage to your MAP. What is the voltage in and out for your TPS?
Remove the vacuum line for the MAP, plug one end with your finger and blow, check for leaks. Blow into the hole in the side of the TB, where the MAP ülugs in, see if it is plugged or restricted. Make sure you don't reinstall the vacuum line into the blind hole in the side of the TB, there are two possiblilties.
I'd do an ohm test on most every sensor wire. And check the harness where it runs down the front fo the motor and underneath to the engine temp. sensor, the O2 sensor and the knock sensor. The front harness has been known to cook onthe manifold and cause shorts. Some of the sensors share a common power supply, if there is a short to ground someplace, the values are gonna be screwed.
Alldata has most of the sensor tests listed and also has a breakdown of the wiring in sub sections. Alldata is a bit easier to understand than the FSM on occasion.
I most always check the connectors and harness first, before replacing any sensors. Everything from your injectors to your CPU and TCU ground at the dipstick holder. Excessive resisitance in the ground circuits, will cause you grief.

[87manche]

check that the distributor is not loose. Problems with the distributor gear would make the motor act like it wasn't indexed properly, and would lead to off idle problems, much as a timing chain one tooth off would.

[Tally_XJ]

is it throwing codes ? do you have a code reader ?


I am not sure how to get the codes. I dont have a reader for OBD1. There is no check engine light on anywhere on the dash but I am not sure it even has one.

[Tally_XJ]

A few things pop into mind, do an ohm test on your CPS, when the motor is hot. Do a resistance test on the CPS wires, you will have to unplug the CPU and will need a good diagram.
Check the reference (input) voltage to your MAP. What is the voltage in and out for your TPS?
Remove the vacuum line for the MAP, plug one end with your finger and blow, check for leaks. Blow into the hole in the side of the TB, where the MAP ülugs in, see if it is plugged or restricted. Make sure you don't reinstall the vacuum line into the blind hole in the side of the TB, there are two possiblilties.
I'd do an ohm test on most every sensor wire. And check the harness where it runs down the front fo the motor and underneath to the engine temp. sensor, the O2 sensor and the knock sensor. The front harness has been known to cook onthe manifold and cause shorts. Some of the sensors share a common power supply, if there is a short to ground someplace, the values are gonna be screwed.
Alldata has most of the sensor tests listed and also has a breakdown of the wiring in sub sections. Alldata is a bit easier to understand than the FSM on occasion.
I most always check the connectors and harness first, before replacing any sensors. Everything from your injectors to your CPU and TCU ground at the dipstick holder. Excessive resisitance in the ground circuits, will cause you grief.


I didnt list it in this post, but I did in the one I mentioned before.
I have already checked the voltage at the MAP and TPS. All were good. CPS ohm's are good.

[8Mud]

Yes, it is OBD1

I am just stupified that it can run perfectly one moment, stall, and then run like absolute hell 30 minutes later.

The only things I have not done is replace the cap rotor, distributor itself and the ECU.

The only thing you haven't done is systematically test the sensors and then the harness. Then basic power supply voltage to the componenets and check other basic automotive stuff.
You said the EGR has been plugged? How so?
CPS is heat senstive, sometimes the motor won't start at all when the CPS is going bad. Sometimes they will not start, start hard and if they do start will run like absolute crap, when the CPS is hot and near the outside of it's resistance envelope. The CPS values change with resistance, you really have to figure the resistance at the CPU plug, you may be picking up excess resisitance in the harness or a connector someplace, which is causing the CPS signal to get flacky.
No spark is often the CPS *circuit* (circuit means the CPS and associated wiring). Fuel problems at idle (way to rich) are often the MAP, MAP circuit or MAP vacuum. If the vacuum is plugged (or leaks) to the MAP or is really restricted, it can cause grief.
I've rarley heard, buying and installing componenets as being an efficient way to troubleshoot a system. It's called getting lucky and actually doesn't happen often.
For every sensor I've ever replaced, I've found 3 or 4 connector, ground or harness problems.
I'm getting frustrated just reading your post :) I'll have to read back through a little more carefully. Have you checked the cam position sensor for input voltage, pulse and shorts?

[Tally_XJ]

The only thing you haven't done is systematically test the sensors and then the harness. Then basic power supply voltage to the componenets and check other basic automotive stuff.
You said the EGR has been plugged? How so?
CPS is heat senstive, sometimes the motor won't start at all when the CPS is going bad. Sometimes they will not start, start hard and if they do start will run like absolute crap, when the CPS is hot and near the outside of it's resistance envelope. The CPS values change with resistance, you really have to figure the resistance at the CPU plug, you may be picking up excess resisitance in the harness or a connector someplace, which is causing the CPS signal to get flacky.
No spark is often the CPS *circuit* (circuit means the CPS and associated wiring). Fuel problems at idle (way to rich) are often the MAP, MAP circuit or MAP vacuum. If the vacuum is plugged (or leaks) to the MAP or is really restricted, it can cause grief.
I've rarley heard, buying and installing componenets as being an efficient way to troubleshoot a system. It's called getting lucky and actually doesn't happen often.
For every sensor I've ever replaced, I've found 3 or 4 connector, ground or harness problems.
I'm getting frustrated just reading your post :) I'll have to read back through a little more carefully. Have you checked the cam position sensor for input voltage, pulse and shorts?


Sorry my post frustrates you 8Mud. All of those parts that I "threw" at it didnt cost me a dime. I have availability to many parts donor Cherokees that are known/currently running Jeeps. The CPS is the only new part I purchased.

My model year didnt have a Cam Position Sensor. That started when Renix ended. Mine does have a hall effects type pickup in the distributor, but I just dont think that is the problem. It idles just too well.

I am thinking it is actually a bad (out of the box) Crank Position Sensor. Of all the sensor diagnostics I did, the CPS readings were the only ones that were "on the fringe".

[bigblackjeep95]

Wow I was just getting ready to post this same exact issue with my 90 XJ 4.0L, A.T., 231 and came across this thread. Mine is doing the same exact thing. It idles fine, rev UP TO 1200RPM and anything after that it just pops and can smell fuel. I was out on a trail ride after 3 hours of continous running we got about 1mile from my house at the end of the trail, took it out of 4wd, moved about 5ft when it backfired and shot out a big puff of black smoke. I haven't had much of a chance to work it, but I did try a few things while off from work last Friday.

Less than 200 miles on new NAPA cap, rotor, wires, coil, and new plugs

Extra KNOWN good parts used to troubleshoot:

spare TPS
spare cap & rotor
spare coil
no vaccum leaks that I could find

Hopefully one of us will figure it out and be able to get our Heeps up and going

[bigblackjeep95]

Almost forgot about this. I also tried another MAP sensor that was good from a running Heep and no difference

[Tally_XJ]

Yeah, your problem does sound just like mine. I am going to try another new Crank Position Sensor since it has a one year warranty and I am in pretty good with the part store I purchased from.

[xjtrailrider]

How is this thing a OBDI if its a 89', have you swapped out the RENIX controls, ecm etc?

I would check and make sure that the distributer is set at #1 terminal when #1 cylinder is at TDC COMPRESSION stroke. I had similar problems recently with my 90' missing/stumbling at off idle cold. It turned out to be my new harmonic balancer's timming mark was not at TDC when the piston was. It had me off by a full tooth on the timming. I will never trust another timming mark on a HB again!.

I'm not saying this is your problem, you may have some distrubuter isues, or a timming chain issue, but if you check the indexing it can either eliminate or show a problem.

Jon

[RNMedic]

have you checked/replace the IAC???

[Tally_XJ]

How is this thing a OBDI if its a 89', have you swapped out the RENIX controls, ecm etc?

I would check and make sure that the distributer is set at #1 terminal when #1 cylinder is at TDC COMPRESSION stroke. I had similar problems recently with my 90' missing/stumbling at off idle cold. It turned out to be my new harmonic balancer's timming mark was not at TDC when the piston was. It had me off by a full tooth on the timming. I will never trust another timming mark on a HB again!.

I'm not saying this is your problem, you may have some distrubuter isues, or a timming chain issue, but if you check the indexing it can either eliminate or show a problem.

Jon

I guess its not OBD1 then cuz its full Renix unfortunately.

However, I do know, from searching NAXJA many times, that on Renix engines, the crank pulley TDC mark should NOT be at "0" when the distributor rotor is pointing at #1. My timing is set correctly, its not a distributor out of time issue.

[Tally_XJ]

have you checked/replace the IAC???


Yes, I did. However, IAC motor has nothing to do with the engine after the throttle is opened. It only controls the amount of air that is allowed to bypass the throttle plate flap when the throttle is closed.

[bigblackjeep95]

Too add more info to my setup, when the heep was tore down I replaced many parts including a new timing chain setup, so I shouldn't have any problems with the chain being loose or the teeth being bend for it to jump time.

Tally_XJ I will be working on my junk Wed and Fri possibly Sat. and i'll give you an update if I find anything interesting or a CURE for this PITA problem we are having. When I read your original post I was shocked at how very close our problem seem to be and how it started.

[Harlee&Tahoe]

I am not sure how to get the codes. I dont have a reader for OBD1. There is no check engine light on anywhere on the dash but I am not sure it even has one.

There is no check engine light, (almost failed smog because of it) Pre- OBD there are no codes to read

[Speed_racer]

I have the same fawkin problem.. but only 1nce a month or so...

I can nurse it home w/5% throttle and a max spd of 28 mph! lol

[FatXJ]

fuel filter or pump

[Speed_racer]

Hey Tally, I was with a buddy last night who's jeep did the SAME EXACT THING as ours!! He rehooked up his IAC, tapped it a few times, and redisco'd it.. and it ran perfect ?!?!

[letank]

You have Renix, it does not throw codes.... the only way around is the multimeter and check values as per the TSM

do a google w renix diagnostic

http://www.lunghd.com/Tech_Articles/Engine/Basic_Sensors_Diagnostics.htm

obviously the fuel pump seems to give you gas... but... the throttle is not responding... test the TPS

renix is very ground sensitive... when you disconnected the various plugs... you cleaned the contacts....

same here..... the engine died.... i could see the tach needle.... jumping.... then no start.... a few hours same... next day same... had it towed home... started to unplug/plug CPS.... coil... then it started.... it has been idling fine in the driveway and around the block.... ordered a new CPS.... it arrived.... will go for a longer drive w the multimeter and the spare cps... and the tools....

Michel
74 wag
90 wrawran

[Anthropy]

I am with FatXJ. I would suspect fuel filter. Fine for pressure when it is at idle, but when you rev it up, it restricts the fuel flow.

Have you checked the fuel pressure then you rev up the engine and maintain a higher rpm?

[Tally_XJ]

I have checked fuel pressure at the highest idle/RPM I can achieve with it acting this way. I get 38psi steady at 1200 RPM. My limit of rev is now 1200 rpm, even then its busting up and spitting, cooughing and sputtering.

[old_man]

I just skimmed this thread. I have a cnupl¤ of que"tions.
Whdn dXd the pbebldm s4`rt>

`d ht sT`rt all of the sudden or get gradually worse?

Have you had the dirtriBttor out for an re`sonN
Havexou che"`ed tha$ the vacuum line from the TB to the MAP is intact and in the correct hole on th!TB?

€Thdre re very@`ew things thatfan cau#` the sdptoms you are seeing. I would be really surprised if it is a CPS. This type of@`ailure`s not grmal for the CV. It c
h't be $de camshaft sensor in the distributor or the IAC.

I have seen a b`d cndl cause silila symptoms, but it ir ra2d.

Myrtandard answer would be distributor indexing or TPS, but with having changdd th` TPS, $bat sho$`dn't be it. BaB` press4pe due $f a plu&`ed exhaust can cause somewhat similar symptoms, but you can normally nticd a affdren` in the sound.

Gnod uck.

[bigblackjeep95]

Tally I don't know about you but this thing is ticking me off. It's about 9:30am here and I'm gonna go fire up the propane heater in the garage for a little while then make a pot of coffee and go see if I can figure my JUNK out.

"OLDMAN" Mine ran for a full 3-4 hours with no problems at all. Came to a stop just long enough to go from 4LO to 2wd and moved about 5-10 feet forward and it shot out a big thing of black smoke and backfired very loud. Now there is a rich smell of fuel when trying to rev it, it misses above 1200rpm just like Tally has said.

I'm gonna go pickup a new fuel filter since its so easy to get to it could use one anyway and I need to locate my spare CPS just to try for the heck of it.

[Anthropy]

Could it be a bad batch of gas? Have you tried some of the dump it in your tank fuel stuff for injectors?

My beastie was running rough even after new plugs, cap, and rotor which normally fixes it. I dumped in a can of fuel injector cleaner and it seemed to really help.

[bigblackjeep95]

Well I just got done working on my junk and nothing has helped at all.

I've now tried using elect. cleaner on all the connection under the hood, looked for vaccum leaks (NONE FOUND), looked for bad wires/bare wires (NONE FOUND), Brand New CPS, Brand New fuel filter, tried unplugging the O2 sensor and (nothing changed for better or worse), added 2 gallons of fuel just to be sure it was 3/4 full, added complete fuel system treatment (let it run for 10-15mins after adding fuel system cleaner). Nothing has helped or made it anyworse.

The only thing I haven't tried is a new O2 sensor.

Anyone got any other ideas?

Thanks,

Barry

[Tally_XJ]

I was aksed today if it was spitting back through the intake. I answered that it was. . . because it does. Kind of a cough, not a full-on back blast, just a cough.

I was told it sounded like a "lean" condition.

If it was a fuel pump or filter, would I have gotten the almost perfect fuel readings I got?

[old_man]

Do you have a coil you can swap in for a test?

The back fire thing has me scratching my head. It sounds like timing. You said it ran for several hours, what all was done previous to the several hours. For it to just start doing this and keeping doing it almost sounds like a timing chain skipped a tooth or something. Could the distributor have rotated?

Having done everything your say, could you have accidentally swapped a couple of spark plug wires? In other words you started with one problem and in the process of troubleshooting, made another problem, then fixed the first, and are now left with swapped plug wires?

Could you have cracked a valve? That would cause the backfiring through the TB. Try a compression test to rule out a lot of not so nice things.

[Tally_XJ]

I think this post has gotten so many replies that things are getting confusing. I know for a fact I did not cross any spark plug wires. They were not even touched after this problem happened.
I dont think it would crank easily and idle so perfectly with any type of valve problem? I agree that I should do a compression test, but damn, it ran so good until it just shut off. I just doubt anything that major happened without some warning.

Here is my symptoms and what I have done so far:

- Jeep shut off at a traffic light

- Towed across street, installed new Crank sensor

- Jeep fired right up, idles perfectly but would not take any throttle without busting up, coughing, spitting.

- Would not rev above 1200 rpm

- Fuel pressure tests at 32psi at idle/36psi at 1000rpm

- Fuel pressure goes to 38psi at idle when I unplug the vacuum from regulator

- I used a donor known running XJ to swap the following parts to mine:
MAP sensor, entire throttle body assembly with TPS and IAC, coil, ignition module, O2 sensor

- Distributor cap and rotor appear to be fine. No play in distributor shaft. Distributor has not been moved and is properly indexed.

- Timing chain isnt even two years old.

- Jeep ran perfectly until the day this started. Twice that day, it shut off with me and took a few minutes of sitting to get it started again (typical of CPS issues)

- I dont have a catalytic converter

This is where I am still at now. Still runs the same, no change.

[bigblackjeep95]

sorry if i am making this confusing on the questions being asked and who they are pointed towards.

My jeep ran for several hours on the trail run constantly. There was no deep water crossings, or nothing that I haven't done before. We actually came out of the trail then came onto a gravel road (I was the lead) before the end of the gravel road the group stopped and shifted out of 4wd, I moved maybe 10feet and it cut out then backfired along with a large puff of black smoke, but never stalled out, it continued to run I just couldn't give it any fuel above 1200 RPM without it cutting out.

[90xj06]

how many miles. have the injectors been changed? my summer car did this when an injector went. sounds weird tho. but throw some seafoam in the tank and see what happens.

[rickoregon]

Understand your frustration. I had nearly the identical symptoms last year when this group of good people at NAXJA helped me down the path to success. Here's the posting at that time (also long) that you may want to read for some clues:

http://www.naxja.org/forum/showthread.php?t=64318

In my case it turns out it was the fuel/rail and/or the injectors. When I swapped out with another set I had as spares, everything was fine..

Don't give up - you'll fix it. This is a great group here, and they will help you find the problem. Rick

[xjtrailrider]

Like "rickoregon" says just stick with it you will get it. Its going to be some little something that will make a big difference. When I had my problems with my 90', Old Man suggested the dist. indexing, I thought I had that covered a few times and I consider myself an accomplished mechanic. But out of respect to his knowledge I checked again and that is exactly what it was. Like me, when you find the problem you will wonder why you didn't check out what you found, first.

Keep diggin' you'll get it!

[bigblackjeep95]

Not sure if this even makes sense, but it was just an idea, feel free to flame...lol Could this be something as dumb as a fuse? If so what fuse would it be? I'm not going to be free until this Friday to start on it again. I'll listen to xjtrailrider & rickoregon and follow the words of the wiser folks on here. I'll be sure to check my dist. indexing again along with a bunch of other crap.

Thanks again greatly for the info. and again I'M SORRY IF I KINDA SNUCK IN ON UR THREAD Tally_XJ and made things a little confusing to follow.

Barry

[gian]

Did you say that you have a vacuum gauge? What does the needle on the gauge do when you hook it up?

[tweakado]

You said you have a hall effect in the distributor right. Check the whole system out when i had a Plymouth with the hall effect in it i found it was shorting out in the distributor. Sounds like the same thing because you at an idle you are not useing the hall effect but when you give it the gas it comes into play and will short or die. If you dont have a shop manual get one makes it a lot easier i got mine from books4cars.com this will show you how to trouble shoot it just like a pro

[RWKHausSupply]

ok well being as I dont have these items any more on my XJ, I cant say for sure if this is it.. But...

With this yr and if its a 241 TC, you have a vac disco front end. You also have those same vac lines that run to the front axle up to the trans case (TC). SO I would start to think that maybe the vac lines are getting a fluid in them when you shift to 4x4 and maybe even just with very high vac.

I would go through the entire engine and remove Every vac line except the MAP sensor and label every hose and plug each orphice that you pull them from. Even the power booster. Then drive it (or atempt to) and just be careful of the hard braking, and see if you still have the issues.

Also check the fluids for the TC and tranny.

Just a thought after reading all this.

PS this is Lookin from over on Pirate.

[BIGDAVE]

I HAD THE EXACT SAME PROBLEMS YOU ARE EXPERIENCING ABOUT 6 MONTHS AGO. WOULDN'T TAKE THROTTLE, BACKFIRING, LEAN SMELL, ETC.
CHANGED EVERYTHING MENTIONED IN THIS THREAD. IAC, CPS, TPS AND THE LIST WENT ON.
FINALLY, I GAVE IN AND CHANGED THE FUEL PUMP EVEN THOUGH THE READINGS WERE GOOD ON THE GAUGE. WOULDN'T YOU KNOW IT-- PROBLEM SOLVED. RUNS LIKE A WHOLE NEW BEAST. PRETTY EASY TO DO, TOOK ME ABOUT 25 MINS.

HOPE THIS HELPS.

[Tom R.]

I HAD THE EXACT SAME PROBLEMS YOU ARE EXPERIENCING ABOUT 6 MONTHS AGO. WOULDN'T TAKE THROTTLE, BACKFIRING, LEAN SMELL, ETC.
CHANGED EVERYTHING MENTIONED IN THIS THREAD. IAC, CPS, TPS AND THE LIST WENT ON.
FINALLY, I GAVE IN AND CHANGED THE FUEL PUMP EVEN THOUGH THE READINGS WERE GOOD ON THE GAUGE. WOULDN'T YOU KNOW IT-- PROBLEM SOLVED. RUNS LIKE A WHOLE NEW BEAST. PRETTY EASY TO DO, TOOK ME ABOUT 25 MINS.

HOPE THIS HELPS.
Dave, what year XJ do you have? I've had some problems with my XJ and the fuel pump is one of the last items on the list of parts that have yet to be replaced. Mine's a '92 and was wondering how easy/difficult the job is. I understand some model years are different, meaning some are easier to do than others. Thanks.

[BIGDAVE]

Dave, what year XJ do you have? I've had some problems with my XJ and the fuel pump is one of the last items on the list of parts that have yet to be replaced. Mine's a '92 and was wondering how easy/difficult the job is. I understand some model years are different, meaning some are easier to do than others. Thanks.

92 XJ LAREDO 4X4 -4.0
IT'S FAIRLY EASY. IT WAS MY FIRST TIME EVER CHANGING A FUEL PUMP.
BOUGHT A HAYNES MANUAL AT AUTOZONE AND JUST FOLLOWED THE DIRECTIONS. YOU DON'T HAVE TO REMOVE THE TANK OR ANYTHING LIKE THAT. I HAVE A 6 1/2" LIFT, SO I DIDN'T HAVE TO JACK IT UP EITHER.

[BIGDAVE]

Dave, what year XJ do you have? I've had some problems with my XJ and the fuel pump is one of the last items on the list of parts that have yet to be replaced. Mine's a '92 and was wondering how easy/difficult the job is. I understand some model years are different, meaning some are easier to do than others. Thanks.

92 XJ LAREDO 4X4 -4.0
IT'S FAIRLY EASY. IT WAS MY FIRST TIME EVER CHANGING A FUEL PUMP.
BOUGHT A HAYNES MANUAL AT AUTOZONE AND JUST FOLLOWED THE DIRECTIONS. YOU DON'T HAVE TO REMOVE THE TANK OR ANYTHING LIKE THAT. I HAVE A 6 1/2" LIFT, SO I DIDN'T HAVE TO JACK IT UP EITHER.

[BIGDAVE]

Dave, what year XJ do you have? I've had some problems with my XJ and the fuel pump is one of the last items on the list of parts that have yet to be replaced. Mine's a '92 and was wondering how easy/difficult the job is. I understand some model years are different, meaning some are easier to do than others. Thanks.

92 XJ LAREDO 4X4 -4.0
IT'S FAIRLY EASY. IT WAS MY FIRST TIME EVER CHANGING A FUEL PUMP.
BOUGHT A HAYNES MANUAL AT AUTOZONE AND JUST FOLLOWED THE DIRECTIONS. YOU DON'T HAVE TO REMOVE THE TANK OR ANYTHING LIKE THAT. I HAVE A 6 1/2" LIFT, SO I DIDN'T HAVE TO JACK IT UP EITHER.

[bigblackjeep95]

I think you may have hit the reply button a cpl times too many...LOL


I have made some progress, I unplugged the sensor on the intake manifold at he rear (temp sensor I think) and wouldn't you know, it starts to run probally 85% than it has, it'll rev a lot more, wasn;t inside so can;t give what the RPM's went upto no compared to the 1200RPM it was at before. However I back out of the garage and was gonna pull around the gravel u-turn drive I live on and only made it about 50ft and it started missing a good bit, like before. But in park it will rev almost perfect when moving the linkage on the throttle body. Can anyone maybe have a sudden brain fart and have some great idea to get me and hopfully TALLY back up and on the TRAILS SOON.

Thanks for all the great info Guys!!! :)

Barry

[Speed_racer]

Did you replace the IAC?

[xjbubba]

Tally-xj--keep us posted on your progress.

[Tally_XJ]

Fixed!!

Actually, I fixed it back in December. I been offline for a while.

It was the brand new Crank Position Sensor that I had just purchased and installed. It was either bad out of the box or I damaged it while installing it. Took one out of a 1988 Commanche and it ran perfect afterwards.

Thanks for all the help and replies!

[rickoregon]

Congratulations! Thanks for providing a followup. It's always good to know the final outcome. Good job. Rick