be4meliz

replaced coil pack, plugs, crankshaft sensor(that one was fun) on checking fire, I am only getting spark to #1 and #6 plugs, have scan tool and getting no codes and check engine light is not coming on. Also have new y pipe with all new cats and when running (barely) for a few minutes,main cat heats up cherry red. I assume this is from unburned fuel(off other 4 cylinders) igniting in cat.(won't do that again) Have re-built pcm on the way as either this or crankcase sensor seem to be only choices left and no check engine light or codes would seem to be indicating Bad pcm. Any way to check pcm(have digital multimeter)? also checked resistance on coil pack and got 1ohm,1ohm, and.5 ohm. according to book should read between.77 and .88 ohms. Could coil pack be bad? ANY HELP WOULD BE GREATLY APPRECIATED AS I AM READY TO NAPALM THIS BEAST! LOLl

tiwvr1

could be running super lean, that will cause glowing manifold also. Check to see i injectors are firing. U can hear them clicking with long screwdriver. DId this start all at once? Or did u buy the jeep like this.

Gee oh Dee

Does it blink a CEL for a little bit once you first try to turn the truck on? If not, the ECU/PCM is probably toast.

You can also pull the PCM and open it up, look for burnt electronic equipement. Or smell it, if its toast it'll smell fishy.

be4meliz

the other thing I forgot to mention was a vacumn leak. I had tested @12-13 lbs instead of 17-22lbs it should be-believe it was from injector o-rings which looked like they'd been chewed up.Replaced those, but can't check vacumn until I can get all 6 plugs firing. Does the crankcase sensor effect spark, or just fuel? Haven't changed it yet, but will wait for results when I get new pcm Tuesday.Compression checked out on engine. so I guess I'm commited on fixing the b**ch, but running out of ideas.This is the4.0 engine; wish I could go back to carb/distributer days- WAY TO MANY ELECTRONICS GOING ON HERE!!! HARD TO ELIMINATE ALL THE POSSIBLE CAUSES WITHOUT GOING BROKE.Thanks for any and all help- started out as a $500 car that needed a little TLC(brakes ,exhaust,etc.) Now approaching the break even mark.

be4meliz

Ya can't polish a Turd

Gee oh Dee

I'm fairly sure the crank position sensor has effect on spark, but I could be wrong. It may not be working because the PCM does not know what the hell is going on and can't give spart at the right time.