Yet Another ZJ Stall Problems Post - 5.2 V8
I have a 94 Grand Cherokee Limited with 5.2 V8 - 185K miles
My saga started about 3 months ago or so when I failed the CA emissions. EVAP system leak and some emission out of spec at idle.
It had been running like sh*% for a few months and I pretty much knew it was probably a clogged cat. Converter.
It had not been a high priority to get it back on the road cause I have other vehicles. Anyway decided to drive to Colo. And have it there.
Got the cat. Replaced as it was indeed clogged. Ran much much better. But it had overheated a couple times and threw a 32 EGR CEL. The EGR was indeed cooked as a result of the cat I had overheated a couple of times. Replaced the EGR (Delphi ) which got rid of the CEL but then I had no fuel pump / stall / no start / no CEL at startup etc. Just like so many threads here.
So here is what I have done:
The 12 Things – ZeeJay’s great post.
#1- The Brain Replaced the Caps and cleaned the contacts. All seems well. Jiggling the harness does not affect anything as far I can tell
#2 – Grounds - Cleaned up the ground conx on the block by the Coil and on the fender near the battery. Is there a third one on the 5.2?
#3 – PDC - Replace the Relay for the Fuel pump. Everything else seems fine. No blown fuses. But I have not taken it apart.
#4 Battery and Cables - 12.46 volts on the battery not running. And 13.85V at idle 500-600 RPM) The battery is less than a year old. Contacts at posts are clean. Cables… are old but I don’t see a voltage problem so….?
#5 Fuel Quality - No Idea. Ran some Lucas last tank full. Don’t thin this is it. I usually buy ARCO here in CA.. I ran this guy in Mexico for 3 years and never had a problem with PEMEX. Fuel Filter is new this summer.
#6 Fuel Pressure - Borrowed the gauge from Autozone. Right on 32 PSI at idle. I am on my third fuel pump so I suspect it from the beginning but it seems to run fine until the stall. And when it stalled at idle, a could here it run for few seconds AFTER the stall.
#7 Ignition - Have not done this yet. I know I have at least 30K on this tune up. Pulled a couple of plugs and they looked okay. The car runs pretty good before the stall so I really don’t think this is causing the stall.
#8 Connections – Have not looked at every connection. But I have been diligent with everything that I have taken apart and reconnected.
Coil wire? Probably should take a look at this.
#9 Wiring – God knows I have moved harness wiring around a lot in the last couple of weeks. I am not sure about this one.
#10 Throttle Body - I have cleaned the TB and IAC. Throttle body only from the top. I guess I should take it off and do the whole deal.
#11 Vacuum Leaks - Have not spent too much time on this one. I do have a mityvac so I need to learn how to use it to check for leaks. I am sure there is write here on that one. I have only used mine to bleed hydraulic systems.
#12 Restricted Exhaust - Resolved. New cat and muffler only a year old.
What else have I done?
New Crankshaft sensor - Had to use a BWD because Mopar is on back order nationwide according to my local Jeep dealer.
New Throttle Position Sensor
New NTK O2 Sensor - What a pain to change this.
So my current status is that it starts and idles okay. After replacing the 02 sensor on Sat. I ran it at idle for 15 minutes and had no big problems. I rev it up and seems to run fine. When I let up on the gas the RPM goes way down to almost stall and then comes back to about 400 plus/minus rpm. Turn it off and starts back up fine. Usually it does. Stalled a few blocks away and I could not get it started. Fuel Pump was not priming and CEL not coming on with key. But, I came back the next morning and started at a few ons and offs with the key,
Now when I test drive, I immediately get CEL after going forward for just a little way. Reverse seems no problem. The code is 32 – EGR.
I am going to do the following:
Fully clean and check the PDC
Take off the throttle body and Clean.
Check for leaks in Vacuum System
New plugs, wires, dist. Cap, rotor
So, what should I do first?