PA Jeeps
The Garage => Technical Advice and Questions => Topic started by: Red02TJ on November 05, 2012, 08:23:36 am
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my jeep is a 2002 wrangler with a 4.0 and 5-speed, has 100k miles.
so my jeep started off with a misfire-type knock. i finally decided to get into the engine's internals and found that a valve lifter was damaged, causing the pushrod to not work. this did not allow #6 cylinder intake valve to open, causing the noise.
i replaced all lifters, lapped the valves, and cleaned the head. checked the slack in the timing chain and verified tdc and timing marks were aligned. after putting things back, i went to start the jeep and it would just crank and not start. the jeep wasn't throwing any codes.
so i checked the fuel pressure and got about 45 psi. i ended up replacing the iac, camshaft position sensor, and crankshaft position sensor.
i tried starting the jeep again and it gave a low rumbled idle and died after 2-3 sec. after many attempts at starting, i got the same results. i even rotated the camshaft position sensor 180 degrees just to make sure the timing was okay. doing this didn't allow the jeep to idle at all, just crank. so i returned the sensor back to original.
i got a spark tester and tested each spark plug boot on the ignition coil rail. i got the same size and color spark for all 6. i checked the resistance of the fuel injectors and got about 10 ohms each. i pulled the spark plugs and smelled gas on them.
so i returned everything back and tried to start it once again. it cranked and cranked and had a low rumbled idle again, then died after 2-3 seconds.
i'm hoping it's not the pcm/ecu. i'm not sure if i provided all of my troubleshooting efforts, but i guess i'm too frustrated with the jeep. any help would be great. also, i was wondering if anyone has an ecu/pcm that i could borrow to see if my jeep would start, preferably for a 2000-2002 4.0 with a manual tranny.
thanks in advance for the assistance.
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i am not in a position to help with the PCM but i was just thinking since you did all the head work that it might be worth checking the compression to make sure there are no issue there. good luck
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an update: compression was good on all 6 cylinders, spark test was good also. apparently i didn't soak the new lifters long enough, so not enough oil in them. i took the valve cover off and a few valves were not opening.
i took a syringe and squirted oil in the pushrod holes and slowly dripped the pushrods with oil. i then took a long flathead screwdriver and cut off the handle. i attached it to a drill and turned the oil pump. this allowed oil to fill the lifters and rods. i restored the cam sensor and synchronizer and the engine started right up!!!
now i have a stipped crankshaft pulley bolt. the never ending battle continues...
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USE EZ OUT TO GET BOLT FREE
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thanks for the info. i did get the bolt out and tapped the threads to clean them up. the jeep is up and running. all that needs to be replaced is an o2 sensor.