'96 4.0 aw4, 185,000 miles.

-with possibly altering initial reaction by telling you what, if anything I've done to it, I'll wait until later. For now, just watch the video and tell me what you think is the problem.

...at around 1:20 on the video you see me hold the throttle open a little- I'm holding it still. Then the engine dies, I restart it...look at the tach near the end...


enjoy!!

http://vid22.photobucket.com/albums/...YPIT%20006.mp4


or try: http://s22.photobucket.com/user/koko...20006.mp4.html

 

...been gone a while recovering from spine surgery.
So 2 weeks ago after I was able to drive since surgery, I drove the Cherokee 1 mile from the house to a local Jeep shop. I know one of their mechanics, so I went by and had him look at it- 'what do you think it is?' I asked. He said "you're distributor is off one tooth- it's easy to do..." (I had replaced the distributor as on of the last things i had done to it). I said cool! I can't bend over for another 3 months to reset it, so he was going to do it for 1/2 hour labor ~ $40 bucks. Awesome.
I dropped it off to get done. He calls me at the end of the day- he said he had installed/removed/installed the distributor 4 times and it had no change.

LOOOOOOONg story short- they had it for a full week.

they tested/installed new: Distributor, CPS, wires, coil, fuel pump, even tried a new pcm...no change. Diagnosed with Snap-On computer every system.
-pulled my plugs that had 200 miles tops on them- they were black and sooty, changed them....but why were they so gummed up? -too much fuel dumped in the cylinders some how, right?
The last thing they checked were the fuel injectors. The resistance checked out ok on all 6, but they disconnected 3 fuel injectors and it made no difference in how the engine was running!! Three injectors!

so, at a total bill of $633.82, I have 6 new plugs and a new fuel pump to show for it, and still have the same problem!

-Their theory is that the injectors are just pouring fuel into the cylinders, leaking out.

I had put in 6 new Bosch 4-hole injectors that I got from a reputable seller back when I did the exhaust manifold and tune up; he said they were cleaned, rebuilt and bench flow tested; they did look brand new
So tomorrow I'm pulling those and putting the old stock ones back in. -Fingers crossed-

Has anyone had a problem with the 4-hole injectors before?

 

Please post the outcome of the stock injectors.

 

Kinda sounds like its searcing for a idle point to me? Maybe it just the video...

 

Man it gets expensive when they diagnose by replacement.
But anyway...you have three bad injectors and that is exactly what is happening, they are dumping fuel in an uncontrolled manner. I'm surprised you didn't get a CEL running that rich.

 

 

they had a Snap-On scan computer hooked up watching all the info on it- when it was idling- on Monday.

I replaced all 6 injectors with stockers.......no change. Won't start- backfires through the intake.

 

Consider the Camshaft Position Sensor being defective.

The CMP controls fuel injector timing as well as ignition timing. The Crankshaft Position Sensor picks up pulses from three sets of notches on the flexplate, which represent three cylinders. 1-6, 5-2, and 3-4. The CMP distringuishes which of these cylinders is at its firing position and relates the info to the PCM. The PCM will then pulse the associated fuel injector and drive the ignition coil to fire that plug.

FYI: The transition from the distributor 4.0's to the coil rail sytem in '00/'01 was easy because the coil rail system fires the spark plugs in two cylinders at the same time (waste Spark system), so all the PCM needs to know is which set of cylinder to fire. The flexplate notches positioned for 1-6, 5-2, and 3-4 already exists.

You said you replaced the distributor. What brand distributor did you install?

You also said the shop tried to install/reinstall the distributor with no change. If you installed a chinese communist distributor (RPT)) there's a chance the drive gear on the distributor shaft is not indexed properly and the distributor will never be installed and timed properly.