Jeep Issues

[toom1h]

Jeep sputters real bad when it warms up. Accelerates like **** (like a miss fire)... But is fine in nuetral when revvin up and in park. Put the transfer case into nuetral and put it in drive and reverse and it was fine. 4lo still ****. 4hi ****.

Dad said he read somewhere that the computers get bad and it does that.. But doesn't really make sense to me why it does it only when it warms up..

My reverse has done it for quite some time. Actually killing itself at times, but finally transfered over to my regular gears....... I think it could need some transmission fluid, (i exchanged the fluid awhile ago and the jeep didn't die in reverse for a little while)...

Any thoughts guys?

[swaggy853]

i dunno how tranny fluid would do that, usually when there is a tranny fluid issue it will free rev and not move at all(my experience).

in my tuning experience loss of power is caused by lack of fuel or timing, which could have a lot to do with the ECU. Could also be a sensor or any other input into the ECU, but could also be something physical like compression, etc. You dont really know without actually doin some troubleshooting on it unless someone has specific experience with these.

[turbodaytona87]

Does your overdrive work correctly (I think it kicks in at 43ish mph)?

[toom1h]

Overdrive isn't a specfic mph from what I know. It is just a higher ratiod gear.


But no, it is all **** rofl.

And I thought it was the ecu as well... but do you really think it would only specifically do it when in gear, and when it warms up? I have had my o2 sensor out for AWHILE and it really hasn't gave me **** till now.


And it could be that the tranny is taking a ****... but why only when warmed up?

[millertime]

vapor lock? just throwing it out there due to the "warmed up" part

[Kelvin]

probly a sensor bad or vaccuum leak or an ecu problem.

[toom1h]

probly a sensor bad or vaccuum leak or an ecu problem.

vapor lock? just throwing it out there due to the "warmed up" part

Once again,,,, only when it warms up and is in drive though?

[Kelvin]

if its in drive the engine is getting load. neutral revving there is no load. does your jeep have a tcu? or tranny ecu? change your tranny fluid

[toom1h]

neither of those from what I have read.


And the tranny fluid isn't that old at all so that would really suprise me if thats the issue. And agreed with shaggy, trannies usually slip badly if tranny fluid is bad/not enough

[Kelvin]

it might be the wrong fluid. check and see if it needs gf4 or gf5, ones safe for specific metals one is not, mixing or putting in the wrong fluid will destroy your tranny.

[toom1h]

oh i don't remember which one it was now, but i did do read ups first then bought the fluid...


The more and more i read, the symptoms I am getting sound more and more like the same ones of an ecu problem.... Weak

[turbodaytona87]

will it restart hot? Sounds more like coolant temp sensor, mine is bad too so I threw in a resister so it wouldn't sputter when it warmed up. You can also try opening the ecu and seeing if the capacitors are leaking/bulging

[turbodaytona87]

How the gas mileage?

[toom1h]

will it restart hot? Sounds more like coolant temp sensor, mine is bad too so I threw in a resister so it wouldn't sputter when it warmed up. You can also try opening the ecu and seeing if the capacitors are leaking/bulging

Okay. Now is there more then 1 temp sensors on jeeps?
I already replaced one, but it still throws the code once in awhile.
And yes i need to check the ecu ;/


And mileage is only a mpg or 2 off because i floor it to get up to speed cause sputtering pisses me off

[Kelvin]

well once the jeep heats up the 02 sensor switches from closed loop to open loop. might be your 02 sensor

[toom1h]

But I haven't had one for a year. Do you think it would take that long to register the issues?

[Kelvin]

uhhhh, yea.

[toom1h]

w0rd, i plan to get a bung put in the exhaust and put an o2 sensor in there to hopefully fix the issue for atleast that...


And i believe i may have to replace another coolant temp sensor cause i thought there was another one on the intake or something?
On jeeps intake/exhaust are on the same side so that may be my issue, just sucking in hot air.

[Kelvin]

sooo you have an 02 sensor just chillin somewhere in the engine bay? or no 02 sensor plugged into the harness?

[toom1h]

No o2 sensor in the harness

[Kelvin]

/thread

[turbodaytona87]

w0rd, i plan to get a bung put in the exhaust and put an o2 sensor in there to hopefully fix the issue for atleast that...


And i believe i may have to replace another coolant temp sensor cause i thought there was another one on the intake or something?
On jeeps intake/exhaust are on the same side so that may be my issue, just sucking in hot air.

I had two different ones, one for the gauge(single wire) and one for the ecu(two wires)

[86Shelby]

DJ, WTF is going on? What I gathered and correct me if I'm wrong;

1. The jeep misfires when under a load all of the time.
2. It does it all time whenever it's in reverse.
3. It doesn't misfire if you go through a certain method of reverse-drive-reverse-nuetral-drive-turn the radio on then off then on again and tap 2 times with your left heel?

Please just check out the simple things.
What do the plugs look like?
Are the wires ok?-did you test them or just look at them and call them pretty?
Why are your O2 sensors missing?
Do you still have catalytic coverters on there?
if the jeep is a mass air system have you checked for vacuum leaks?

there are a lot of things that begin to fail once they warm up.

[toom1h]

DJ, WTF is going on? What I gathered and correct me if I'm wrong;

1. The jeep misfires when under a load all of the time.
2. It does it all time whenever it's in reverse.
3. It doesn't misfire if you go through a certain method of reverse-drive-reverse-nuetral-drive-turn the radio on then off then on again and tap 2 times with your left heel?

Please just check out the simple things.
What do the plugs look like?
Are the wires ok?-did you test them or just look at them and call them pretty?
Why are your O2 sensors missing?
Do you still have catalytic coverters on there?
if the jeep is a mass air system have you checked for vacuum leaks?

there are a lot of things that begin to fail once they warm up.


k here i go
The jeep misfires after it warms up and is under a load.
I've noticed before I thought it did it in reverse when under any load, but is actually after it warms up and is under a load.
It only doesn't misfire in nuetral or when the transfercase is in nuetral (also does it in 4lo)
I haven't checked the plug or wires, I'll be looking at that hopefully tonight.
Missing an o2 sensor because I removed the back cat, but the front o2 sensor along with cat is still there.
No MAS, and I finally cleaned out the TB. And I haven't checked overly far into vaccum leaks but it seems pretty secure...
-From the VMAs- Nothing is what it seems though

[Kelvin]

oooh. front o2 is important not rear. probly somethin. else. did you detail the engine or anything

[supeRtunermatt]

jeeps are for girls so if we got together that would make you ***** in the relationship

[Lepa]

great info matt, glad u could give ur imput.

[toom1h]

oooh. front o2 is important not rear. probly somethin. else. did you detail the engine or anything

No, I'm not sure of any previous info from this ecu. I know its not the ORIGNAL (numbers different etc), but dad bought it from some jeep crazed guy who knows his stuff supposibly. But I dunno it could just be bad.

The jeep no longer would start. Fuel related, could be ecu not telling the fuel pump to well pump or could be fuel pump / fuel filter related. I wouldn't mind taking the gas tank down and replacing the fuel filter anyways. May end up doing that this weekend.

[toom1h]

jeeps are for girls so if we got together that would make you ***** in the relationship

THIS IS THE TECH SECTION NO YELLOW TEXT OR SARCASTIC COMMENTS ALLOWED

[turbodaytona87]

oooh. front o2 is important not rear. probly somethin. else. did you detail the engine or anything

No, I'm not sure of any previous info from this ecu. I know its not the ORIGNAL (numbers different etc), but dad bought it from some jeep crazed guy who knows his stuff supposibly. But I dunno it could just be bad.

The jeep no longer would start. Fuel related, could be ecu not telling the fuel pump to well pump or could be fuel pump / fuel filter related. I wouldn't mind taking the gas tank down and replacing the fuel filter anyways. May end up doing that this weekend.

When you turn the key to the on position, does the check engine light come on for a second or does it take a few seconds?

[toom1h]

Dont overly pay attention to that. But usually on as soon as I turn the key on.

[turbodaytona87]

now that it won't start, see if the check engine light comes on right away.

[toom1h]

Meh I don't feel like driving across town

Dad felt like buying a new ecu so I'll just wait till then. Plus its nice just using teh gfs ride. Her parents let me stay at her place this way.

[turbodaytona87]

ok sounds good

[toom1h]

But if I get time to look at her today (doubtful) I'll let you know. And if the ecu doesn't work I'll be back.

[millertime]

jeeps ftl, not really, I like them,

[toom1h]

jeeps ftl, not really, I like them,

Wrong section.

[4sfed]

Sounds to me like you just have a misfire issue. I am willing to bet it needs a major tune. (plugs, wires, cap, rotor, pcv)DO NOT get aftermarket parts. Go to a mopar dealer and get the tune up kit it is actually pretty cheap.
They also had problems with sucking the lower intake pan gasket. This will cause running problems as well as oil consumption.

[turbodaytona87]

he has the 4.0 if I'm not mistaken which doesn't have the lower plenum gasket issue like the v8s

[4sfed]

^^^You are correct. Disregard the the whole intake thing. My money is still on the major tune up though.

[turbodaytona87]

Mine had the plenum leak and would ping just cruising along once it warmed up. Then pulling a car trailer really didn't help anything.

[toom1h]

Sounds to me like you just have a misfire issue. I am willing to bet it needs a major tune. (plugs, wires, cap, rotor, pcv)DO NOT get aftermarket parts. Go to a mopar dealer and get the tune up kit it is actually pretty cheap.
They also had problems with sucking the lower intake pan gasket. This will cause running problems as well as oil consumption.

To bring this thread back to life, I found the issue while I was out of town.
Basically even if I would have been the ones to install the plugs I probably wouldn't have known, but jeep eat the bosch platinum (any of the plats, plugs and wires) for breakfast. Found two spark plugs destroyedddddd. Hurray for 4cyl. And that doesn't say I was getting much out of the wires.

Did a minor tuneup as far as plugs and wires, and she was back on the road.


So you win the prize. Wish I would have noticed this sooner.

[BOORAH]

Its a jeep thing.