drgnhrt1979

ok, so here is my problem that I need some help with. I have given all the info I have or know to try and get the best answers to this problem. Thanks in advance to all who contribute...

on July 8th, I was involved in a MVA and when I started my Jeep after all the information was exchanged and the cop said I could go, my engine light started flashing at me. I turned off the engine and restarted and it stopped flashing at me for a while.

a few days later it started flashing again. I got the codes read, most where misfire codes that I could hear through the exhaust. the rest were TPS and MAP related, erased the codes, and most of them came back.

Now, I just had a mandatory trip to PA. While driving, every so often, the engine light would flash at me. when it did, I could not get the RPM's over about 2800 b4 the Jeep would jump and buck like it was at is limit and there was a revlimiter preventing it from going faster. in addition, I have low oil presure and my volt gauge spiked a few times (3) on the way home. to get the engine light to stop flashing or to get the volt gauge to go back to were it's suposed to be, while at highway speed, i would put the tranny in N, turn the key of for a few seconds, then restart the engine and then i could drive normal again for a while. usually the engine light would start to flash again, when i would slow down to under 40-45 MPH or the tach would get under about 1500 RPM.

the current codes are for misfires again and the TPS volt not agreeing with the MAP (P0121).

What I have done so far after getting the codes...

I have checked my coil rail when i changed spark plugs and 2 of the 3 packs tested higher than the upper limit, have to get that replaced ASAP.

Tested the TPS and it was within specs, think its fine but will probably replace it just for good measure

looked for the MAP, couldnt find it, it is not firewall mounted, so I think it is on the throttle body, but dont know where, may have to go to the stealership to get it checked, unless someone here can help me with where it is located and how to check it. will probably replace that as well

If anyone here can help me figure this out with the least amount of cost, I would appreciate it a lot. Thank you again for your help.

EDIT/UPDATE: Just got my codes read again today on my way in from work...got the usual misfire codes, the P0121 for the MAP and TPS not agreeing, and a new one P0740, has some thing to do with the torce converter not engaging like it should...

mh_jenkins

I have a 1999 Cherokee 4.0 and getting the same P0740 code.

Andrew0257

Never run the jeep if the ce light is flashing...Means bad things are happening.

Mattpar

you need to get those misfire codes figured out before you can go after the torque convertor code. Ya never know, the misfiring and bucking could be throwing the trans code as well

Reason why the check engine is flashing is cause its misfire and dumping raw fuel down the exhaust which will ruin the catlictc(i can never get that word right) converter.

kbad

hey man....x2 cat....with jeeps, a rapid flashing cel means cat is going bad....plugged up exhaust will cause misfires and throw cel.....check the cat, it could've got banged up and loosened up enough inside to cause it to plug up....it may rattle some (like dice in a can) if you bang it with your palm (when cold).....you can try removing the rear o2 sensor (closest to cat) and see if it relieves the back pressure....at ~1800rpm is the resonant frequency of the cat, where it would cause the most issue, also if you drive in reverse up hill.... good luck!

Dugualla

What type of MVA did you have, where was the damage? Check all of the wiring harnesses, look for damaged harnesses, connections on the power distribution box in the engine compartment, loose wires or connections on the alternator, engine, everywhere.

With all of the different sensors, codes, other electronic seeming gremlins that just so happened to start after the accident I think you should try to eliminate electrical issues first. BTW, the PCM is behind the air box, check those connectors also.

I always disconnect the battery when I am plugging and unplugging connectors.

rich

The map sensor is on the front of the tb looking from the grill in replace your coil pack and boots check the vendors on here for the coil pack its the cheapest I ve seen. Two check your grounds and as far as your oil ressure what is low.

phxmark

The flashing MIL means to SERVICE NOW! Don't run the engine anymore than you have to or you WILL seriously damage something. Had a 1996 Intrepid that did that and a couple of days later the timing belt broke. At least it didn't damage the engine. The code that was set indicated the timing was off.