AdmiralSavage

Hello guys, I recently acquired a 2002 Jeep Grand Cherokee Laredo with the 4.0 inline 6 engine 4x4 for $300. It has 250k miles. The owner was leaving the country and couldn't take it since it was too old and had another vehicle he was going to take anyway that he has been driving so the Jeep has been sitting for a couple of months. When I first went to see it, we were able to put my battery in and get the engine to turn on since the other battery died from sitting so long. The engine wouldn't Idle so i held the throttle and my mechanic said the engine sounded good at least. After a while it did idle at 400rpms but would easily stalled so he said we would have to clean the throttle body. Later once we got all the paperwork done, I filled the tank to get that old fuel out. When we removed the air intake and left the throttle body exposed we turned the car on and it wasnt sucking air through the idle air control so we changed it out, cleaned the throttle body and the car idled right up again. Only issue with it now is that the transmission shifts from 1st to second at about 30- 40 MPH. I dont hear any unusual noise from the transmission and when it shifts it shifts fine and drives fine. I put in my scanner and got the code for P1762 which is related to the transmission. Also sometimes while in 2wd the part time light will come on and off randomly. Another thing is the oil pressure Gage will go down and the check gages light will be on until it randomly decides to turn back on and the light disappears. Other than these minor issues this Jeep WJ is pretty much all solid.

RockinRonnie

Welcome to the site AdmirralSavage !

AdmiralSavage

Thank you!

dave1123

Replace the governor pressure sensor in the transmission (P1762). Your oil pressure sensor is probably not functioning correctly. The "Check Gauges" light comes on because the oil pressure indication on the gauge is below normal. My advise it to replace the pressure sensor with a Mopar part. If the engine bearings aren't rattling, you've got pressure. The gauge just isn't showing it.

AdmiralSavage

ill do all that and change the fluid and filter. Also spark plugs due to slight misfires in 4 5 and 6 and the fuel tank cap since i have the evap code and mine doesnt click in. The misfirr you cant feel it, it just occssionally flashes the cel and the scanner tells me those 3 cylinders.

AdmiralSavage

Hmm ive been driving the 02 WJ Jeep for about a month now, all is good except that transmission issue. I already have the sensor and parts for it but I need to get the mechanic to do it still. Another issue which rarely happens is out of nowhere you will feel the Jeep misfire and it doesnt go past 3k rpms and idling you can feel the misfire badly. If I turn the car off and turn it back on the issue goes away for a long time. Any idea what it could be?

AdmiralSavage

Got an update, i changed the governor pressure sensor in the transmission along with the fluid and filter. Car shifts fine now. Spark plugs also changed car feel better. I will keep checking it for a while see if it needs anything else.

Dwight Hunt

I chased this damn thing for 1.5 yrs on my own so I am goin to just tell u, spend the $118 and just go get a mopar crank sensor , it will have an AB ,AA, AC , after the part # in yellow and if u can get it re-synced with the cam sensor (the electronical distributor ) do so, but instead of making it learn it self this will speed the process and drive great from the start..... and will help smooooooth out the rough idle and a better throttle response. Yw hope it all works out gor u as it did for me, finally......

dave1123

There is no "syncing" involved with the crank sensor. All it does is tell the computer where the engine is in it's rotational cycle. The cam sensor (electronic distributor as you call it) controls the fuel injector timing data sent to the computer. THAT has to be timed if it's been removed. It has a plus-or-minus richness range that can be adjusted with an active scan tool while the engine is running. The spark timing is totally controlled by the computer by reading the pulses from the crank sensor and data from vehicle speed, MAP readings, and engine rpm, temperature and other data to determine proper spark timing for the engine load. This engine also uses a "waste spark" system where 2 plugs fire every revolution, one on compression and one on exhaust in order to reduce emissions. Jeep now recommends NGK ZFR5N spark plugs in this engine with the coil rail because Champions tend to run hot and cause detonation.