Hi Jeep Gurus !
My XJ is driving me nuts! It would start and run for ten minutes or so?
Now it is dead ,cranks but refuses to fire?
Ok here is what I have done --- New crank sensor,new cam sensor, new fuel and asd relays
last week new coil and set of plugs,new IAC,
All my checks with multi meter showed correct specs ?
Now seeing as it started and ran before cam sensor and coil I am going to refit old ones
and at least it should fire up again? New coil shows less secondary out put than new one?
new fuel pump about five years ago still gets a good spray at valve?
I have checked all connections in PDC none loose or hanging ,also cleaned all grounds that I can reach?
new battery ,alternator is a bit sus but i charge batt after playing lol
ok we are talking about a 1995 XJ Sport AW4 and stock l6
any ideas how ever outlandish will be gladly received
Many Thanks for reading this far!!
Yesterday ,not even any readings from OBD11 key on key off ,but worked two days ago? duff ignition switch,
or no grounds from PCM?

 

PCM/ECU failure? I believe the only way to test that is to swap one out for another. Mine gave up the ghost with no warning. Went out one morning and had a no start condition and the obd port was dead....when through a series of other tests...you can read the thread about it ... https://www.cherokeeforum.com/f2/sen...roblem-251669/
hope this helps

 

It sounds like you've gotten spark taken care of. Did you replace plug wires when you replaced spark plugs?

It sounds like fuel is mostly taken care of, but I would check a few things. You said you replaced the fuel pump in the last 5 years. What about the fuel pressure regulator? What about the fuel filter? What about the fuel injectors? Are they leaky? When you started up your Jeep the last time, did it stumble while running?

What brand are your new sensors like the crankshaft position sensor? These Jeeps can be finicky with what electronics you put in them.

 

Im down the same rabbit hole as you brother. 1500 in parts and two local repair shops that gave up. Now looking for a pro shop. Or, an engine swap.

 

Though it's stated what all has been replaced, I don't see directly - Does it have spark? What fuel pressure is it getting at the rail?

Now for rabbit hole my experience, I had a section of wire harness bwhind the alternator that was splitting, jeep would occasional run fine- but suddenly lying cut out and retunr to just fine. Before throwing all the nonsense at it while it was running I start shaking grounds and various parts of the wire harness until I found the affected area. I could consistently manipulate the poor running so I pulled another engine harness form the junkyard and cleaned all the grounds upon install. Everything was fine after that!

 

thanks for reply Mtn Goat,
I have reached the point where I have to make a tough decision! I have owned mine for 27 years and here in Australia they are now very scarce ,even in junk yards!
It has been a very reliable car over the years ,on its third crank sensor ,but the cam sensor and coil are original since I bought her in 1997 ,only replaced a week ago!
I have an auto electrician coming to see what he can find, but living in a country town the choice of repairers is limited???
I can only wait now until this guy comes,then I make the decision, ! Market value here is anywhere five hundred AUD to about 2000 for an exceptional one ?
This country is flooded with Landcruisers which DO have a reputation for reliability!! XJ's were on the back foot right from the beginning back in the eighties,
I will keep the forum updated

 

Thank you Bruce for all the info from your post ,I have an auto electrician coming to test it all for me as it is a bit above my pay grade!
I would like to get a PCM as you did, but it would cost me some 800AUD by the time all charges are added, and as XJs are only worth
five to 1500 AUD Spending that much on it seems a bit stupid? I think I will part it out depending on what my auto lectrician comes up with?
14th is D day so I will keep you all posted
thanks again!

 

might be worth $50 bucks or so to try and source one from a salvage yard. Best if you can find a 1995 with matching engine and transmission.
or...member Dave51 has experience in opening and repairing the PCM's... you may want to contact him and he may be able to give your electrician guy or yourself enough info and instruction on repairing it.
Hope this Helps.

 

Thanks Bruce
I will wait until my electrician has an investigation when he comes on the 14th!
Only PCM I have found is used and unknown? Bit chancy at 400aud dont you think?
also he is claiming no numbers as painted?? Very suspicious?
Anyway fingers crossed mine is ok, and the cam sensor is faulty out of the box?
It was not Chinese at 104 dollars !!!!
Coil only has 50% of the OHMs of the old genuine one so I will put the old one back
I will keep you posted
Mike

 

Thanks Bruce!
Had a look around locally and the best I can find is a " pays your money,take your chances" PCM

I will play on Saturday with ignition switch see what I have got there? A switch online is 180aud,
Problem I have ,is there are only two Cherokees in junk yards in this town both very gutted and obviously no PCM
in them anymore!
I had a crazy idea,what if i made up two jumper leads ,bypass ASD -then run a ground wire to a bolt nearby? is that likely
to work? Or will it do more harm than good?
Whatever they say about sensors being beneficial ,I would still prefer a HEI distributor wirh coil to suit and an adaptor for
a two barrel carb! LOL

 

Hey lets take a big step back here.

Does it have spark at the spark plugs when cranked ?

Do the injectors have 12V on one side?

Do they pulse if tested with a light when cranked ?

Thats what an auto electrician will test for first, but charge you hundreds of $

 

Hello All !
Big thanks to Bruce B , and all of you who offered suggestions!
Auto electrician (owns workshop but goes out doing diagnosis) Well he went through all the items I had replaced,and
gave grounds to pump and ASD relays Halleluja it fired up!- ran like a Swiss watch *(new throttle body ,TPS,IAC<,MAP also?),
He gave the advice to not do this as fuel pump will be constant,but for test purpose no harm done! (PCM not giving grounds)
He is sending my PCM down south for repairs (one of the hassles of living in a nice seaside country town)
He only charged $90 aud call out fee, but obviously will cop a markup on the PCM?
Anyway guys ,I have decided to give the old girl a new lease of life, it deserves it! After 25 years good service whats a few hundred bucks????
Thanks again guys,and I will keep you posted when my PCM returns!

 

AWG
Ok you were correct it did none of those things when cranked,
THE SPARKY SAID PCM WAS NOT GIVING GROUND TO RELAYS
AND ALSO INTERMITENTLY DROPS OUT INTERNALLY
See my update post

 

I see you have 2 threads

I am presuming you may lack sufficient electrical knowledge to test whether you had a bad wire that supplies earth from PCM to relays

The "easy way is to run backprobed "piggyback" wires to rule that out

If you have not done so, join one of the OZ Facebook Jeep sites and check Gumtree, I expect a 94-95 PCM could be had for $200

You are correct that a lot are getting junked, mainly due to electrical or auto trans failures that are worth more than the car to fix

Ring some wreckers as well

The PCM number should be on a sticker

In Oz, we only had 94-95, and they were OBD1 PCM

96 and later have OBD2. I have a spare '96 PCM, bought privately

You need all the parts that will fail and are hard to get on hand if you want to keep them on the road

I have a complete running spare '96

 

Hi AWG
FROM YOUR COMMENTS YOU ARE ACTUALLY IN OZ???
I SENT A PICTURE OF MY STICKER TO A MOB IN MELBOURNE AND THEY SAID THEY DO NOT HAVE A CHANGE OVER
UNIT BUT WOULD NOT GIVE ME ANY SUPERCEEDED NEW NUMBERS? EITHER THEY CANT OR WON'T?
I KNOW IT IS 27 YEARS OLD AND I HAVE HAD VERY LITTLE TROUBLE FOR 25 OF THOSE YEARS,JUST USUAL RUNNING REPAIRS
MINE IS 95 BUILD BUT REGISTERED AS 96? IT GAVE ALL THE FLASHES ON THE KEY CYCLING,,SO FROM WHAT YOU SAY IT IS OBD1?
IT ALSO HAS FIBREGLASS NOSE AND TAILGATE?
HOW DO i TELL IF IT IS OBD 1 OR 11 ?
PCM IS P56041 200JBSAA T3265 AND AT TOP BARCODE IS JGE06VZS IF YOU KNOW OF ANY OTHER NUMBERS THAT THIS SUPERCEDES
TO OR CAN BE USED i WOULD APPRECIATE IT VERY MUCH
THANKS