Please help!!!

[schndtryme]

Hey all, I am new here and having difficulties with diagnosing problem, hope someone can help. I have a 1992 Jeep Cherokee Laredo with a 1994 4.0. I recently had a cracked manifold (bad) and kept driving it for awhile. I recently noticed an oil leak and traced it to blow by from PVC on valve cover. I replaced Both with new hoses, including the hose to the MAP sensor from manifold. I took it to the car wash to use engine cleaner on it and spot free low pressure rinse. The next day in which was a day before my new Manifold was delivered, the vehicle had hesitation problems only on acceleration and threw the check engine light. I thought no problem the manifold is cracked pretty bad so I thought after replacing the manifold and gasket and exhaust O ring, I would be fine. Well here I am 5 days later scratching my head. It idles great revs up great but after reving up and hitting 4 to 5 a couple of times mind you, it will finally throw check engine light on. When taking off it has torque sounds great but going down the road normal and then as soon as you punch accelerater down it hesitates and throws the light. So I replaced O2 sensor. Still does it. I have tested MAP sensor, throttle position sensor, they check out fine. Found from another site how to get codes and they are 12, 13, 14, 24, 51. (MAP sensor putting out high/low voltage, MAP no change during engine off on, check TPS sensor and wiring, O2 sensor detecting lean mixture), Sorry guys but I am at a complete loss. I don't know what to do. All vacuum lines look good and connected used water to try and locate any leaks. Took catalytic converter off to see if any difference. Did the same thing. Can an IAT sensor affect any of this? Its cheap so maybe I will replace just for a try. Please if anyone knows what to do. i am going nuts with this. the jeep ran great never a problem before changing the PVC's on valve cover. Also checked distributer for moistness, checked plugs. The plugs, wires, rotor, distributer cap, all replaced a year ago. Just put new K and N air filter in same time as PVC valves. UGGHHH

 

[schndtryme]

BTW if it helps the check engine light goes off upon restart on its own until the accelerater is punched. Won't go off until vehicle shut off. But it did go off why running when I sprayed break cleaner (all I had) LOL into throttle body to clean why running when I returned inside the vehicle check engine light had gone off until again I punched the accelerator and bam it came back on. Hope this helps.

 

[Bounty__Hunter]

You shouldn't spray any solvent into the throttle body when the sensors are attached. I'd recommend removing the throttle body and the sensors, giving the throttle body a good bench cleaning once the sensors are removed.

I'd bet a new TPS might solve your problems.

As for the oil in your intake coming from the manifold, pull the line from the valve cover to the air intake at the air intake end, make sure it has strong vacuum into the engine. If it's pushing air out, the CCV system is working in reverse.

 

[schndtryme]

Thanks Bounty Hunter, I have an update, wish I would have read bounty hunter's post first but seems ok what I did. I just finish spraying throttle body cleaner in throttle body and manifold through the inlets, changed out IAT sensor. It seems to have more punch when first taking off but still acceleration problems and throwing light. I cleared the codes and ran it out. Returned home and checked codes again. The only codes being read now are 12 battery disconnect, (no problem) and code 24 (throttle position sensor) Bounty hunter is right. Now then I checked this sensor and it checked out fine but I had it out, so now maybe it just needs adjusting? or maybe it really is bad. Not sure yet would like to try adjustment first. Does anyone know how to properly adjust this sensor? Thanks. Getting closer!!! Yeah. What a sensitive nightmare.

 

[schndtryme]

Update. Thanks allot bounty hunter!!! Replaced throttle position sensor. RUNS GREAT AGAIN!!! Problem solved.

 

[superj]

Good job man!

 

[Bounty__Hunter]

Good to hear. And there's no TPS adjustment on '91+ Jeeps.