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Discussion Starter · #1 ·
I went on a road trip into the interior last weekend andhad no problems. I parked the jeep on Sunday and let it be until Tuesday.
I started her up tuesday and noticed that when driving if I gave the engine a bit more gas it seemed to skip or not grab. It would sputter along until the shaking when away.
I notice this only when I need to accelarate or when I need a bit more power. This problem seems to occur in any gear....but it doesn't happen everytime.

Can anyone help me out? I'm running out of ideas of what it can be.

Thanks

Angelo
 

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Silverback
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Hard to say with that kind of vague symptom, but it sounds like a fuel delivery problem.

How full/empty was your gas tank at the time?

It could be an early sign of your fuel pump starting to go; it could be a little condensation in the tank.

Throw in a little methyl hydrate to rule out the "water in the gas" issue and see if things improve.

When my fuel pump went I had intermittent symptoms of loss of power under acceleration - kind of a jerking, stuttering, especially on the uphill when power demand was up. Beware when it finally gives up the ghost, 'cause you won't be going anywhere.
 

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Superfly
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aandre said:
I went on a road trip into the interior last weekend andhad no problems. I parked the jeep on Sunday and let it be until Tuesday.
I started her up tuesday and noticed that when driving if I gave the engine a bit more gas it seemed to skip or not grab. It would sputter along until the shaking when away.
I notice this only when I need to accelarate or when I need a bit more power. This problem seems to occur in any gear....but it doesn't happen everytime.

Can anyone help me out? I'm running out of ideas of what it can be.
Could be a clogged fuel filter or catalytic converter. But since it doesn't happen all the time, I'm more inclined to suspect the fuel filter.

...lars



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Discussion Starter · #4 ·
Well.....I replaced the fuel filter....the same problem.
Here's a bit more info on the problem.

If you place the jeep into second and let the RPM's go down to 1500 or so. Then press on the pedel and the engine seems like its summbling or not getting the gas or something.

Anymore idea's?

Thanks.
 

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Superfly
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aandre said:
Well.....I replaced the fuel filter....the same problem.
Here's a bit more info on the problem.

If you place the jeep into second and let the RPM's go down to 1500 or so. Then press on the pedel and the engine seems like its summbling or not getting the gas or something.

Anymore idea's?
Possibly a bad TPS or throttle stepper motor.

Have you done a diagnostic read out test?


...lars



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Discussion Starter · #6 ·
Hey Lars,

I got the results.....here we go.....

33
27
55

The first code has something to do with the A/C clutch relay.
The second is the problem. The first infector is not responding...I guess.

Any ideas on how to solve this????

Thanks.

Angelo
 

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The first thing I'd do is make sure the wires to your injectors are all plugged in. I had this problem before and it was a loose connection. Of course, this was after a motor swap when I disconnected the fuel rail.

Since the error doesn't specify which injector is bad, it could be any of the four (what makes you think it's #1?).

One cheap way to figuring this out is to borrow a injector from another 2.5L and replace it of your injectors (one at a time, of course), to see if the problem goes away. I suspect that a 4.0L injector is the same as your 2.5L injector. SOMEONE near you must have a 4.0L injector you can borrow.

The factory service manual should have some suggestions on troubleshooting that particular fault. Do you have an FSM??

Also, ignore the AC error...it just means it can't find your AC but if you don't have one, then it's no big surprise.

One other thing to consider: you've got 11 year-old injectors. It wouldn't hurt to have 'em cleaned-out. At the same time, the shop could check to make sure they're all within spec. Of course, this would cost money...

...lars



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Discussion Starter · #8 ·
Thanks for the info.

I have a FSM and will see if I can get an injector.
Now, do I have to replace all the injectors or just the one that is giving me all the problems?

Thanks

Angelo
 

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aandre said:
I have a FSM and will see if I can get an injector.
Now, do I have to replace all the injectors or just the one that is giving me all the problems?
Just the one(s) that is giving you problems. However, if you send your injectors to a shop to get 'em cleaned, they can send you back a replacement set that is balanced (ie: all the injectors in the set perform very close to the same). This is supposed to improve performance.

...lars



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Discussion Starter · #10 ·
Where can I go to get the injectors cleaned?
I know that I can remove the injectors and soak them in cleaner or is it just better to send them away to be cleaned?

Thanks

Angelo
 

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same problem too

I also get the same problem. Every morning when I leave for work, I have to backout and down a slight slope. Then I would put it in Drive ,up another slight slope for almost 5 seconds and the engine would sputter or hesitate, similar to the engine not grabbing any fuel. It would also produce a very loud tapping or kocking sound. I can feel it on the gas pedal. This happens at least 8-9 times out of 10 mornings.

I complained about this to my dealer and suggested that it might be the fuel filter but they say the filter might not be the problem. They tried to replicate the problem but couldn't. So it's not fixed yet.

It's a 1997 Jeep Cherokee XJ. 4.0L. The fuel filter is about a year old.

Anyone have any ideas?
 

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Discussion Starter · #12 ·
Hey Reddy,

Try and get the codes out of the computer.
See if the numbers match up with mine.

Good Luck,

Angelo
 

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Re: same problem too

Reddy said:
I also get the same problem. Every morning when I leave for work, I have to backout and down a slight slope. Then I would put it in Drive ,up another slight slope for almost 5 seconds and the engine would sputter or hesitate, similar to the engine not grabbing any fuel. It would also produce a very loud tapping or kocking sound. I can feel it on the gas pedal. This happens at least 8-9 times out of 10 mornings.
I hate to sound like a parrot by going off on the TPS all the time but if it is faulty, it will give false readings to the computer-controlled AW4 transmission can make weird shifts, which make the engine seem like it's hesitating. Did you get the engine soaked shortly before the problem began?

Definitely read the diagnostic codes to see if everything is ok.

...lars



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aandre said:
Where can I go to get the injectors cleaned?
I know that I can remove the injectors and soak them in cleaner or is it just better to send them away to be cleaned?
Let your fingers do the walking in the Yellow Pages (or Super Pages as I think they're now called). Soaking them in cleaner ain't gonna do the trick. Of course, we're assuming that it is the injectors that are faulty. Did you check the connections?

...lars



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Like Lars said don't just pop in a new injector. Make sure that is the problem. Go to Lordco and get a set of noid lights fairly cheap 20 or so bucks. This will allow you to test your connectors for all the injectors. Also make sure that your fuel system is running at 14-15 psi..


Good luck
 

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mechanics illiterate

errr...actually i'm not very familiar with auto mechanics so i don't understands terms like tps or AW4...

i think what you guys are referring to is a little computer thingy that plugs into the other thingy under the dash board...right? then it reads the jeeps computer for codes...so these codes are suppose to tell you what's at fault...

and also about the "engine getting soaked"...do you mean something like crossing a river? if yes...i did not cross a river or get the engine soaked
 

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Re: mechanics illiterate

Reddy said:
errr...actually i'm not very familiar with auto mechanics so i don't understands terms like tps or AW4...
TPS = throttle position sensor
AW4 = automatic transmission commonly used in Cherokees

i think what you guys are referring to is a little computer thingy that plugs into the other thingy under the dash board...right? then it reads the jeeps computer for codes...so these codes are suppose to tell you what's at fault...
Depends...earlier Cherokees can get the codes by manipulating the ignition switch (read the YJ FAQ: http://www.bc4x4.com/faqs/yj.cfm and search for "diagnostic"). They don't require a tool to read the codes. Not sure if the '97 can do this or not.


and also about the "engine getting soaked"...do you mean something like crossing a river? if yes...i did not cross a river or get the engine soaked
How 'bout washing it? Did you wash the engine?

You never answered about the injectors; did you check that they were firmly plugged in to their electrical connectors?

...lars



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Discussion Starter · #18 ·
Lars,

I checked the connections and they seem to be fine.

Like Lars said don't just pop in a new injector. Make sure that is the problem. Go to Lordco and get a set of noid lights fairly cheap 20 or so bucks. This will allow you to test your connectors for all the injectors. Also make sure that your fuel system is running at 14-15 psi..
By the way...what are noid lights? Sorry...still new to this game!

Thanks

Angelo
 

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Discussion Starter · #19 ·
Well,

I took the Jeep into a shop today to find out what was going on.
They got back to me in about one hour and said that I need the following:

-cap, rotor and wires.
-decarbonization service

I can do the first part.....but what about the second?

Has anyone done this service before? Is this something that I can do myself?

Thanks.

Angelo
 

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aandre said:
Well,

I took the Jeep into a shop today to find out what was going on.
They got back to me in about one hour and said that I need the following:

-cap, rotor and wires.
-decarbonization service

I can do the first part.....but what about the second?

Has anyone done this service before? Is this something that I can do myself?

Thanks.

Angelo

Angelo

um, the old fashioned way is to take it out and drive the piss out of it at higher revs then normal. change the cap and rotor and rotor and go have some fun. the other way is to take a vaccum hose off something(cant remember if ya need manifold or ported vacuum maybe somebody here knows) and stick it in a bottle of water(yes I did say water) and hold the throttle to keep it running. you will need a small vacuum line so it dosn't suck to much water and I dont recomend this unless you are completly sure of what you are doing, its not a pleasent feeling to do this when you know what the results of a motor inhaling large amounts of water can be.

at a shop or dealership they use a "special" fluid that they pour down the intake to do pretty well the same thing except they hold throttle to keep it running for about 1/2 the bottle then they pour it in untill it stalls and leave it sit for about half an hour(something about it disolves the carbon). used to do this at a honda dealership I used to work for using the fluid from a GM labeled bottle.

ooops, I had the wrong quote in there, corrected now


DMMcG said:
Throw in a little methyl hydrate to rule out the "water in the gas" issue and see if things improve.
I wouldn't recomend doing this, not supposed to be good for injectors. just fine for carbs though and much cheaper than using the stuff from wall mart or something but if injected dont use methyl hydrate
 
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