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Discussion Starter #1
whats the procedure for timing the 2.5l? i dont have a vac advance and i assume something has to be unplugged to get a correct timing reading.?
 

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Discussion Starter #2
so how come the 2.5l isnt adjustable on the distibutor position? how do you adjust timing?
 

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Your computer should reset the timing on that year on its own. I could be wrong, but if you want i could look it up on our computer system at work and see what I can find out. I worked on a 87 cherokee which was having timing problems. Put a new timing chain in it and the computer adjusted itself.
 

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Discussion Starter #5 (Edited)
Your computer should reset the timing on that year on its own. I could be wrong, but if you want i could look it up on our computer system at work and see what I can find out. I worked on a 87 cherokee which was having timing problems. Put a new timing chain in it and the computer adjusted itself.
i snagged a extra distributor at the boneyard a few days ago and it looks like the dist can only go in 2 ways since the end is slotted like a flat head screwdriver. im geussing 180degrees off if its backwards or right where its supposed to be..anyway my rotor looks like it sitts kinda loose on the dist. i geuss my tach might be off.what would cause the thing to idle at 2k sometimes? i got a injector from a commanche and swapped it in the idle seems better now, i also swapped out the map sensor off of a newer 4.0 rig that made no differance, the injector did though.this thing reads 171000 miles. i wouldnt think it would feel so gutless. and i swear it feels like it should have a 5th gear. 4th is way too high on the freeway (3k rpm). the shift nob is missing so at first i really wondered if it was a 5speed with a bad 5th. did 86 come with a 5speed?
i remember driving a 87ish cherokee cheif at a car lot i worked at and it felt pretty peppy. why is my laredo such a dog?
im going to do a comp check here soon to see how worn the motor is.i like that this is a 2 door so i might just run it till it breaks and swap in a 4.0
my 86 toyota 22r carbed 2wd with 250k has alot more power than this jeep so i really think somethings wrong. i know i have a big exaust leak at the manifold or close by other than that unless the cat is plugged up im cluelless as to why this is suck a turd. it doesnt leak oil or burn it either.hmmm.
 

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... i wouldnt think it would feel so gutless. and i swear it feels like it should have a 5th gear. 4th is way too high on the freeway (3k rpm). the shift nob is missing so at first i really wondered if it was a 5speed with a bad 5th. did 86 come with a 5speed?
i remember driving a 87ish cherokee cheif at a car lot i worked at and it felt pretty peppy. why is my laredo such a dog?
im going to do a comp check here soon to see how worn the motor is.i like that this is a 2 door so i might just run it till it breaks and swap in a 4.0
my 86 toyota 22r carbed 2wd with 250k has alot more power than this jeep so i really think somethings wrong...
...close by other than that unless the cat is plugged up im cluelless as to why this is suck a turd. it doesnt leak oil or burn it either.hmmm.
so I am gonna revive this old thread and hope someone out there could have a suggestion or two as to what is going on with my 98 JGC.

So I just finished putting on a high flow muffler and tailpipe today, because I have some issues with available power at cruising speeds. My get up and go is okay, but something is retarding the abilty/power of the jeep. I will be cruising just fine, but there is no power difference between 10% pedal and stomping the pedal to the floor.

I have a suspicion that the APN header I put in three years ago has cracks in the welds(most likely multiple), but I had to fix the muffler 1st before really opening up the engine for exploratory surgery. The Dynaflow muffler(SS and fully welded 2000 CFM) sounds and peforms great, but did not solve the limp biscuit problem that I have.

My brother and I are going to do some exploration with a compression gauge and we're going to properly reset the distributor timing. I had done some adjusting to the distributor after having some dirt make it down the shaft. So, I could have messed up the timing when I did so. He seems to think that we may be one or two teeth off of a proper timing/distributor alignment. yeah, yeah.. the PCM takes care of the timing, I know... trying everything we can think of.

I am also thinking that it could be a partially plugged cat, but the downstream O2 seems to be acting just fine. I should also mention that I have no known codes in the PCM. There are no check engine lights, and the jeep runs okay, with 16.7 MPG around town and 21 MPG highway.

So, in your opinion what COULD be the issue with the lack of power when stomping on the pedal?

Edit: BTW, she starts up instantly and I have upgraded 8.5mm wires, bosch plugs, accel HI coil, performance cap and rotor kit, plus the injector upgrade on the fuel side.
 

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I know putting the distributor in can be a pain. You have to start way off and anticipate the roll from the gears meshing.

Here are my suggestions,

TPS
Air filter
fuel pressure
Auto trans shift cable
 

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Not the distributor timing either . Just reset my distributor from TDC on #1, and reset it in there. Also cleaned out the IAC sensor on the throttle body. I am wondering if perhaps this bored over TB is giving the computer some issues?

I did manage to crack the porcelain on three Bosch Double Platnum Spark Plugs. I am still at a loss on how that happened, but the Yeti is still running good; but not the best it could be. It, my Jeep, is still limp [email protected]#$d when getting on it while in a cruising gear. The umph just isn't there before the kick-down engages on the transmission, and unless it is in a lower gear; it will not put you slightly in to the seat.

I had reset the PCM after everything was done, so maybe after a week or so of driving it; something will come back.

Next up will be checking the exhaust manifold for leaks/cracked welds, and probing the transmission for issues.

any other ideas?
 

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We also did a compression check:

#1: 172 psi
#2: 172 psi
#3: 145 psi
#4: 159 psi
#5: 169 psi
#6: 178 psi

That's pretty good for an engine with 188,000 miles on it, but it still doesn't help much with diagnosing the problem.
 

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Did you adjust the trans shift cable?
Have not gotten that far yet. We believe that the issue is engine related, but once the next few things are out of the way, diagnostically, we will be moving to the transmission.

It IS a 42re, and has 187,000 on it. It has been well taken care of, but there is definitely some 'adjusting' that needs to be done to it. I am not a transmission guy. I do not work on them. There are a few things externally I am willing to do but I will most likely find a rebuilt or brand new one. i am hoping that there is a new, unused one out there; however, I am thinking that they haven't made one in decades.

We shall see. I have to go and dig out the auto scanner so I can get a better read on the sensor values while the car is in motion. Unfortunately, that means digging through 30-40 unmarked boxes in a storage unit.:brickwall:

Thanks!
 

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I'll probably readjust it in the morning, but i am thinking it really would not affect the sluggishness that I am experiencing. I would think it would mostly affect shifting too hard/soft, the timing of the shift, and/or slippage...

i am really just getting sluggish response when using the lead foot so...
 

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It may be a lot of work, but you may want to pull the fuel rail, check each injector individually by unplugging all but one at a time. turn the key on and work the the throttle and see if the pattern is consistent throughout all the injectors.
 

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It is not the transmission throttle valve cable.

I just changed all of the injectors over about 5-7,000 miles ago. The injectors are all rebuilt and new. I'll probably run some injector cleaner in the next tank of gas to see if that'll do it.
 

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I replaced all my injectors, but after a couple months, one started leaking. Started smoking, knocking, and running bad. Had them replaced. No problems since.
 
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