Jeep stalling under hard acceleration ??

[mattvw65]

i have a 91 4.0 5 speed.
when on the gas fairly hard 3000 + rpm. the while jeep lurches like it just dropped the tranny. then back fires and dies. pull over to the side of the road wait less than a min. it will start back up and im on my marry way. just as long as i do not open her up. i just got back from a 5000 + mile trip. drove the jeep to florida from utah. and no problems the whole time. was out side of evenston wyoming. when this started. seems to be getting worse. :wow:

matt

 

[rockdog]

stall

fuel filter or fuel pump would be my guess. had about the same problem on an 88 chev truck. changed the pump, never did it again.

 

[pokeyYJ]

check fuel pump relay, check injector ecu, check plugs and wires, distributor if ya got on.

I would try and duplicate the problem in your garage before I went out and replaced the fuel pump.

 

[I Lean]

Check your catalytic converter, sounds like it might be toast...loose chunks of stuff plugging your exhaust.

 

[mattvw65]

Check your catalytic converter, sounds like it might be toast...loose chunks of stuff plugging your exhaust.

there is a story to that one i can tell you that is not the problem


let me tell you a story sorry abought the spelling

tuesday night i was driving from riverdale to
layton the freeway entrance from riverdale is kind of one when you get out of
the loop you get on the throttle it startted to bog as i entered the freeway it
drove normal i continued south bound twords
layton i wasalmost to the 1rst clear fild exit when it started to bog and
sputter i applyed moer gas that was when it back fired then stalled abought
that time i noticed the floor on the passenger side smoking i pulled
over !! ripped the fire extengusher out and started pulling the carpet back as
much as i could ......... i took a look under the jeep and the cat was cherry
red the under coating on the jeep was on fire!!! just abought
that time a car had pulled over to give me a hand it was a older guy he said he was fowoling me and my jeep was dropping fire balls out the exzaust!!! hitting the cement and spreading like spatter from a cutting torch abought a 1/4 mile down the road it had cought the grass on fire i had the fire department ther soon after and utah highway patrool theay got the grass fire put out asked me if i was fine i have allready called my dad to come and give me a tow home .........

when i got home i pulled the cat out the hunny comb was totaly
melted so i went to a frinds to have him help me fab up a quick fix pice of 2
1/2 exzaust pipe were the cat was then took it for a test drive i got abought 2 miles away when it stalled out same sutdder pop and died
so that was not the problem it was destoried becouse of my problem i have
orderd a new cat off e bay and will install it asap for all you enviromentle guyes

 

[mbryson]

there is a story to that one i can tell you that is not the problem


let me tell you a story sorry abought the spelling

tuesday night i was driving from riverdale to
layton the freeway entrance from riverdale is kind of one when you get out of
the loop you get on the throttle it startted to bog as i entered the freeway it
drove normal i continued south bound twords
layton i wasalmost to the 1rst clear fild exit when it started to bog and
sputter i applyed moer gas that was when it back fired then stalled abought
that time i noticed the floor on the passenger side smoking i pulled
over !! ripped the fire extengusher out and started pulling the carpet back as
much as i could ......... i took a look under the jeep and the cat was cherry
red the under coating on the jeep was on fire!!! just abought
that time a car had pulled over to give me a hand it was a older guy he said he was fowoling me and my jeep was dropping fire balls out the exzaust!!! hitting the cement and spreading like spatter from a cutting torch abought a 1/4 mile down the road it had cought the grass on fire i had the fire department ther soon after and utah highway patrool theay got the grass fire put out asked me if i was fine i have allready called my dad to come and give me a tow home .........

when i got home i pulled the cat out the hunny comb was totaly
melted so i went to a frinds to have him help me fab up a quick fix pice of 2
1/2 exzaust pipe were the cat was then took it for a test drive i got abought 2 miles away when it stalled out same sutdder pop and died
so that was not the problem it was destoried becouse of my problem i have
orderd a new cat off e bay and will install it asap for all you enviromentle guyes

My CPS acted like that. The misfire caused my converter to melt down. BUY THE CPS FROM THE DEALER. It's twice as much, but it's worked awesome while one I bought from Autozone caused me to 'fix' a lot of other things.

 

[JF1]

If you got the cat hot enough to melt the honeycomb, then I would wager your O2 sensor is now kaput and is throwing off air/fuel ratio.

 

[MR.CJ-7]

I agree with the O2 sensor.

 

[redrockcrawler]

try starting off really hard if it does it off the line it could be a fly wheel position sensor you could not be getting contact or the trans could be seperation from the motor

 

[mattvw65]

ok........ still have the problem ........
here is the list of the things i have changed

o2 sensor mopar
cps mopar
ballast resisitor mopar
cat magna flow
fuel filter car quest
had the fuel press checked all good there. i was on my way to slc when it died last i was not on the throttle i was just cursing 70 ish did not want to melt my new cat down so i just coasted to the emergencey lane ....... it took for ever to fire up not like before where when i stopped it would just fiire up it took probaly around 20 minutes or so i have taken it to the local dealership and had the computer codes checked the only codes were o2 and the ballast resistor?
plese help

matt

 

[JF1]

Since you already changed the cps, see if any of the cps wiring is touching the exhaust manifold as it goes down the firewall and on to the tranny housing. I've seen one melted to the exhaust manifold. Taking a while to start is a surefire sympton of a bad cps like Marc said.
If that turns out ok, I'd post on NAXJA to see what they have to say. Perhaps it is the cam sensor on the distributor?

 

[mbryson]

Since you already changed the cps, see if any of the cps wiring is touching the exhaust manifold as it goes down the firewall and on to the tranny housing. I've seen one melted to the exhaust manifold. Taking a while to start is a surefire sympton of a bad cps like Marc said.
If that turns out ok, I'd post on NAXJA to see what they have to say. Perhaps it is the cam sensor on the distributor?

My connector on the CPS had issues also. Hope that helps? (that sucks!)

 

[H-K]

My connector on the CPS had issues also. Hope that helps? (that sucks!)

can you replicate this problem while at a standstill?

Sounds like you've already tried to fix the obvious things, how about fuel rail/injectors? Ignition tune-up items?

 

[CJJ92yj]

i have a 91 4.0 5 speed.
when on the gas fairly hard 3000 + rpm. the while jeep lurches like it just dropped the tranny. then back fires and dies. pull over to the side of the road wait less than a min. it will start back up and im on my marry way. just as long as i do not open her up. i just got back from a 5000 + mile trip. drove the jeep to florida from utah. and no problems the whole time. was out side of evenston wyoming. when this started. seems to be getting worse. :wow:

matt

Did you say "Jeep" and "Hard Acceleration" in the same sentence???

Just kidding though. I have a '92 Wrangler with the 2.5L and a 5 speed. It was acting all weird too, like it had lost a huge amount of power. I did a tune-up earlier this week on it anc shen I changed the fuel filter, I could not beleive that anything had been getting through it. It was completely full of crap. If you've never changed it before, or even if it's been a few years, it's worth the money to do it again.

 

[mbryson]

.............. the 2.5L ..............

You said accelleration and 2.5L in the same paragraph.......

 

[mattvw65]

Did you say "Jeep" and "Hard Acceleration" in the same sentence???

Just kidding though. I have a '92 Wrangler with the 2.5L and a 5 speed. It was acting all weird too, like it had lost a huge amount of power. I did a tune-up earlier this week on it anc shen I changed the fuel filter, I could not beleive that anything had been getting through it. It was completely full of crap. If you've never changed it before, or even if it's been a few years, it's worth the money to do it again.


CHANGED THAT



can you replicate this problem while at a standstill?

NOPE I CAN DRIVE IT ALL DAY LONG AROUND TOWN WITH OUT ANY PROBLEM

Sounds like you've already tried to fix the obvious things, how about fuel rail/injectors? Ignition tune-up items?


NOPE AND DID A COMPLETE TUNE UP BEFORE THE TRIP TO FLORIDA


Since you already changed the cps, see if any of the cps wiring is touching the exhaust manifold as it goes down the firewall and on to the tranny housing. I've seen one melted to the exhaust manifold. Taking a while to start is a surefire sympton of a bad cps like Marc said.
If that turns out ok, I'd post on NAXJA to see what they have to say. Perhaps it is the cam sensor on the distributor?

ZIP TIES ON ALL THE WIREING
THE CAM SENSOR IN THE DIST I WAS TOLD ONLY HELPS THE START UP THEN IS NO LONGER NEEDED ? MY ISSUE IS ON THE FREEWAY

 

[CJJ92yj]

You said accelleration and 2.5L in the same paragraph.......

Good Point, he's at least one step up one me there!

 

[riskeacj5]

It could be a combination of an aging fuel pump ( static pressure may check good but pressure falls as load/volume increases) and a bad ballast bypass relay.

 

[re-jive]

problem after multiple fixing attempts

ok........ still have the problem ........
here is the list of the things i have changed

o2 sensor mopar
cps mopar
ballast resisitor mopar
cat magna flow
fuel filter car quest
had the fuel press checked all good there. i was on my way to slc when it died last i was not on the throttle i was just cursing 70 ish did not want to melt my new cat down so i just coasted to the emergencey lane ....... it took for ever to fire up not like before where when i stopped it would just fiire up it took probaly around 20 minutes or so i have taken it to the local dealership and had the computer codes checked the only codes were o2 and the ballast resistor?
plese help

matt

I've never had this problem before, but it sounds like it may not be so much of a mechanical problem. I would check more into the electrical side and see whats up. The best mechanics i've talked to are at Auto Haus on state and about 5400 S. they do mostly foriegn cars but the guy who owns the place is awesome and straight foreward. Check it out he may be able to help.

 

[re-jive]

problems problems problems

I've never had this problem before, but it sounds like it may not be so much of a mechanical problem. I would check more into the electrical side and see whats up. The best mechanics i've talked to are at Auto Haus on state and about 5400 S. they do mostly foriegn cars but the guy who owns the place is awesome and straight foreward. Check it out he may be able to help.

AHHHHH.... .after reading all these i'm starting to get pretty freaking mad myself. All these angry signs.........aHHHHHHHHHHHHHHHH. Makes you just want to crush the thing into a cube after all this, but keep calm, talk to some pro's, maybe even sell the SOB. -