91 jeep wrangler drivability

[artfuldodger00]

hello everyone maybe you can help with a problem i inhereted.
108m on a jeep wrangler and this truck runs like crap. bucking spiting sputtering . no power pinging . i have preformed every test on every component myself so i know there accurate. the only part that has not been replaced is the computer. trying to find the correct information has been a whole different story . its a 2.5 fuel injected PORT INJECTED. and it seems to me that this is the culpret. a new computer is $600 but its the only thing that has not been checked or replaced. any input would be greatly appreicated. one guy i spoke with {a svc mgr at a large dealer said that it quite possiably is a crack in the intake port and is leaking vaccum under a load . it just doesent make sense for this to respond this way thanks don

[Ray H]

You didnt say how long it has been doing this. Could it be a tank of bad fuel. For some reason it just sounds fuel related. Change/check the fuel filter? Maybe sediment in the tank? Just some things to think about.

[fredjacksonsan]

You said you replaced "everything"....how about tune up? Needing a new set of plugs, a new cap and rotor and a set of wires can cause the problem.

[artfuldodger00]

[quote=artfuldodger00] hello everyone maybe you can help with a problem i inhereted.
108m on a jeep wrangler and this truck runs like crap. bucking spiting sputtering . no power pinging . i have preformed every test on every component myself so i know there accurate. the only part that has not been replaced is the computer. trying to find the correct information has been a whole different story . its a 2.5 fuel injected PORT INJECTED. and it seems to me that this is the culpret. a new computer is $600 but its the only thing that has not been checked or replaced. any input would be greatly appreicated. one guy i spoke with {a svc mgr at a large dealer said that it quite possiably is a crack in the intake port and is leaking vaccum under a load . it just doesent make sense for this to respond this way now im updating and will be a little more graphic its not fuel . i drained the tank and replaced the fuel pump .
these are the replaced items .
fuel pump
filter
plugs
wires
cap & rotor
cam pos. sensor {distributor} oem complete
crank position sensor
pressure regulator . timing is fixed so thats out .
new coil
new map sen
new coolant temp sen. all new vacuum lines.
and as of yesterday i broke down and bought a $600 computer from mopar and guess what .........yep you guessed it not a mother fu$#%@#. change of any thing . the compression is in spec . i will give any body who can solve this mystery $250 out of my own pocketb if you can tell me the problem.. thats a promise from mr fixit

[Ray H]

Im goin for the 250 now
Grasping now!
What kind of condition is your exhaust in? Is your cat clogged or the exhaust pinched?
You do know that after you disconnect the battery, it takes a little while for the computer to reset and it may run pourly for a few minutes? If you didnt give it some time after disconnecting the battery, you may have fixed the problem and not realize it.
Your timing chain could've skipped. Check the marks.
Double check the plug wires/rotor for firing order.
Dirty or bad injectors.

[artfuldodger00]

well i can tell by the response ive recived. no jeep super gods here. it s cool ive been dealing with this friggin customers problem for over a month now . thanks to all who gave there 2 cents but i assure you this is one bizzare problem . ive been a mech for over 20 yrs and i can tell you this is just plain wrong. im stumped .....especially now that ive even tryied the computer. thing , now im having thoughts of jeep suicide. strictly on the level of course . maybe accidently routing the sparkplugwires through the fuel tank or something quick and painless . any ideas???/

[Ray H]

Originally Posted by artfuldodger00

maybe accidently routing the sparkplugwires through the fuel tank or something quick and painless . any ideas???/

Idea: Dont forget to video it.

[artfuldodger00]

[quote=Ray H]Idea: Dont forget to video it.[/quote]
well ive got news and ive got news. first is that i am pleased to tell you all that the issue has been solved. it would now appear that a combination of worn injectors and faulty ignition signal to the return path of the computer. sounds lame to me to but thats the only way to put it. now i can collect my meger wage and not look back until next time . thanks to mopar , chrysler and the folks at jeep for there useless insight into a very simple problem. hell, if it wernt for my devoting all the time i had available for almost two weeks i might have sent a f@#$ you letter to these fine establishments but i fear ive wasted enough time here talking about it already. thanks to all who made an effort . donny