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View Full Version : Going to light my jeep on fire!!!!


bcmaxx
06-22-2010, 10:45 AM
1989 jeep cherokee limited 4.0, auto.

I am going to set my jeep aflame if I can't track down this problem!! Calling all xj guys for help....!

Heres the problem:
After the engine becomes warm and the jeep is shut off and restarted is runs like all hell and puffs black smoke, almost make your eyes water. like its lost a few cylinders. If I bring up the rpm and hold it for a short time it clears up.
After prolonged crawling at will also start to miss a bit and clears up when revved. I have had the same problem for a few years now and it was there with my old tired 4.0 as well.

Here is a few things I have done to try and help with the problem:
- new injectors, cooltaped injectors and rail, cool taped the intake and runners
- new fuel pump and filter
- 850cfm electric fan wired to run always
-raised rear of hood 1-3/4" to help alleviate under hood temps
-mopar thermostat, jeep never gets hotter than halway up gauge
-new 2 row rad- converted to a normal rad cap (no green turtle)
-ZJ hd clutch fan
-plugs cap, rotor
-new cps
-checked all grounds, added more batt to chassis, batt to engine and engine to firewall grounds
-new 02 sensor, new coolant temp sensor, new air intake temp sensor, new map sensor.
Tonight I'm going to install a new distributor just for shits and giggles.

Thats is all for now, I will courier a bottle or equivalent of your choice to the door of whoever can help me solve my issue[cheers] . I am at wits end with this one.


I also have a winch up front- would this inhibit the airflow to the rad dramatically enough to cause heat problems? Like I said it never gets hot http://i232.photobucket.com/albums/ee110/bcmaxx/wubba.jpg

OldEnuff
06-22-2010, 11:36 AM
Try disconnecting the vacume line going to your EGR valve and cap the line so it doesnt leak.
Had a similar problem once and it was the EGR system activating at the wrong times.
Never did find out if it was sensors or computer, easier to just deactivate the egr valve.

Good Luck

Jim

tryn2wheel
06-22-2010, 12:42 PM
id try slappin on a new egr valve....

bcmaxx
06-22-2010, 01:02 PM
things on my list to try:
-isolate egr
-install new dizzy
-unplug coolabnt temp sensor, check for any change

Apathy
06-22-2010, 01:05 PM
EGR or AIV.

both can do it.. however, EGR would be my first guess.

dirka dave
06-22-2010, 02:10 PM
Change the air in your tires !!


:hitler:

bcmaxx
06-22-2010, 02:13 PM
Change the air in your tires !!


:hitler:

Did that, no improvement. The air did smell like circus critter though?:dontknow:

kootenaycat
06-22-2010, 04:43 PM
Can you get data stream on that old OTC Genisys you got there? Watch MAP reading when it's puking out fuel. And put a fuel guage on it and see what it's going to, maybe the fuel regulator is acting up. :dontknow:

Come buy my Heep for a parts vehicle, runs awesome. :D

Chopstick
06-22-2010, 06:32 PM
check to make sure you didn't burn through one of your vacuum lines that go to your map/maf sensor (cant remember the name of it now, shit) thats bolted in your firewall, vacuum line goes from your intake manifold body to the sensor.. a friends jeep did that and made it run like ass!!! you losing a shite load of power too??

bcmaxx
06-23-2010, 09:41 AM
check to make sure you didn't burn through one of your vacuum lines that go to your map/maf sensor (cant remember the name of it now, shit) thats bolted in your firewall, vacuum line goes from your intake manifold body to the sensor.. a friends jeep did that and made it run like ass!!! you losing a shite load of power too??

The line is good that goes from throttle body to map, I checked it first, yes it does lose power gradually. Distributor did nothing, tried unplugging the coolant temp sensor as well. going to pull the egr tube off and cap the intake and manifold.

dh_4_ever
06-23-2010, 06:04 PM
unplug the EGR. the wire to the black silinoid on the fender. when mine acted up I just unplugged its controls, doesnt turn on.

bcmaxx
06-24-2010, 10:19 AM
I disconnected and blocked the line going to the egr,vacuum tested the valve, tested the resistance and inputs of the cts and air intake temp sensors. Going to try another o2 and another map tonight.
still have yet to remove and block egr tube.

kootenaycat
06-24-2010, 04:17 PM
What's the fuel pressure doing when it acts up?

bcmaxx
06-24-2010, 05:05 PM
What's the fuel pressure doing when it acts up?

Not sure, I have had a gauge on it before when it acted up, fuel pressure maintains.

xj too old for any of our scanners, our new genisis only goes down to 91.
replacing tonight: map sensor, fuel pressure regulator, and 02 sensor. I'll mount our gauge to the a pillar if I have time

England
06-24-2010, 05:40 PM
so whens the fire ??? Ill bring some burgers !

4skin
06-24-2010, 11:18 PM
does it have a cold start injector if it does un plug it se if that changes things

atoyot
06-25-2010, 12:08 AM
mmmmmm .....jeep fire............i smell hotdogs.....

Redneck Lincoln
06-25-2010, 12:11 AM
my sisters jeep did what your describing, egr

vajayjay
06-25-2010, 12:49 AM
Burn it way up in the bush, and we'll come recover it for ya:D

bcmaxx
06-25-2010, 08:15 PM
bcmaxx
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Re: going to burn my jeep.....
Reply #31 on: Today at 11:59:54 AM
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Installed new o2 and air fuel meter.problem still there if not worse.meter switches between neutral and rich.when the problem exists it's full rich until it clears out then it switches rapidly until things smooth out.so definitely rich. Eliminate egr is next

kootenaycat
06-25-2010, 09:45 PM
does it have a cold start injector if it does un plug it se if that changes things


It's not a Toyota! :D

kootenaycat
06-25-2010, 09:51 PM
=bcmaxx
Installed new o2 and air fuel meter.problem still there if not worse.meter switches between neutral and rich.when the problem exists it's full rich until it clears out then it switches rapidly until things smooth out.so definitely rich. Eliminate egr is next

Problem with not having a data stream is you can't tell what the PCM is receiving for inputs. Even with replacing all these sensors is you don't know if there's a bad signal return wire. Subaru still got the same scan tool? It has a lab scope option, find a schematic on your heep and see what the signals are doing at the PCM connector then compare to a known good signal for said sensor. Should be able to find them online somewhere - shopkey, mitchell on demand, IATN, etc.