Jeep Chrekee problems

O

old

Well-known Member

Location

Camdenton Missouri

• Jul 1, 2010

• #1

Well I replaced the crank shaft sensor and the coil on it and still no spark. It is that 4.o 6 cylinder and you guys said the crank sensor but that did not work. Also checked fuses and found the ignition fuse bad and replaced it but still no spark. Did find that the wire going to the crank shaft sensor had a burned spot in it so maybe it shorted out and blew the ECM so what do you guys think?? Cost the guy around $100 in parts and still a no go thing. Hate to see it because he is tight on $$ and has been out of work for a few months

 

K

Kevin (FL)

Member

• Jul 2, 2010

• #1

Old,

What year model is the Cherokee? I'm driving out to a fellow a few miles from our place on Friday. He's got several Cherokee's on the property selling parts. I'm going to try getting a PCM for the 98 I'm having AC clutch trouble with. I figure they're at least a couple $100 new?? Hopefully he'll have one similar to the one I need and he may have some other year models too.

 

A

Anonymous-0

Well-known Member

• Jul 2, 2010

• #1

Have someone check for service bulletins on your particular year...some of those Cherokees had an update for the craks sensor that included replacing some of the wiring to the ECM [the '88 Comanche pickup I had needed that upgrade].

 

A

Anonymous-0

Well-known Member

• Jul 2, 2010

• #1

"crank" sensor...

 

O

Old Roy

Well-known Member

• Jul 2, 2010

• #1

was the CPR ( Crank Positioning Sensor) on my 98 Grand Cherokee.a bear to get but, make sure you leave the sticker on the face new one as it automatically sets space between pickup on flywheel

 

T

ted regentin

Member

• Jul 2, 2010

• #1

Old, take off a connector for one of the injectors and put a test light across the terminals and see if the test light flashes on and off when cranking the engine over. Let me know what happens and I can give you more steps. Hope this helps.

 

A

Anonymous-0

Well-known Member

• Jul 2, 2010

• #1

Check the coil wire had same problem same vehicle same problem wire burnt internally.

 

H

huntingreen59

Member

• Jul 2, 2010

• #1

Do the dash instruments work? All my gages quit working when my crank sensor quit. The darn thing was running fine one evening and would not start the next day. Found some videos on the net that told how to check and change it. As soon as I replaced the sensor the gages started working and the jeep started. I just did a search on Google (jeep grand Cherokee won't start)

 

D

Dieselbreath

Member

• Jul 2, 2010

• #1

My son's girlfriends cherokee had no spark. After many people looking at it someone found a hit on the internet and it turned out to be a broken wire at the computer.

 

C

Chuck (CA)

Well-known Member

• Jul 2, 2010

• #1

Ignition module in the distributor?

 

OP

OP

O

old

Well-known Member

Location

Camdenton Missouri

• Jul 2, 2010

• #1

The crank sensor is the first part I put on yesterday and that did not help

 

OP

OP

O

old

Well-known Member

Location

Camdenton Missouri

• Jul 2, 2010

• #1

That was the first part I put on yesteday and that did not work

 

OP

OP

O

old

Well-known Member

Location

Camdenton Missouri

• Jul 2, 2010

• #1

It is a 1992 Cherokee Laredo with the 4.0 6 cylinder engine. Fuel injected. I figure it is most likely a bd ECM but not sure

 

R

RusselAZ

Member

• Jul 2, 2010

• #1

Does the coil power up when cranking? It won"t have power until the ASD relay is grounded by the ECM when the ECM sees a "cam" signal from the pickup inside the distributor.

See if the distributor is turning and the metal plate is still riveted to the shaft.

The cranksensor is not used for turning on the ASD and fuel relay. It is used for injector sequence and timing curve(per rpm

Knowing the logic of a system saves money.

 

A

Anonymous-0

Well-known Member

• Jul 2, 2010

• #1

Those have in-line fuses and if your ignition fuse was bad; it could have blown that. I wanted to whip the idjut that thought that up!

 

OP

OP

O

old

Well-known Member

Location

Camdenton Missouri

• Jul 2, 2010

• #1

What is funny on it is that is has power to the coil but no spark which leads me to think ECM is bad

 

A

Anonymous-0

Well-known Member

• Jul 2, 2010

• #1

If your down to guessing, I'd go with the distrubutor assembly. About 60 bucks at rockauto.com (after core).

Could be your fix.


Dave

 

K

Kevin (FL)

Member

• Jul 2, 2010

• #1

Spoke to a fellow today who sells PCM's for $50. I had asked him about one for a '98. The only problem is getting one that has the exact same options as the vehicle being fixed.

I worked a little on the '98 today but still didn't get the AC clutch problem fixed. Also wasn't able to go see the local man who had some Cherokees on his property. Getting ready to run over to New Orleans on Sat for a wedding.

 

B

Brian Jasper co. Ia

Well-known Member

• Jul 3, 2010

• #1

You need a scan tool to properly diagnose your no spark issue. You need to be able to see if the PCM is getting a CKP (crankshaft position AKA RPM) and CMP (Camshaft position) signal. I don't know on a Jeep for sure, but most vehicles when they loose CMP signal, they stop dead in their tracks, or will not restart after being shut off. GM 3.8 is one exception to that rule. 9 out of 10 PCM's replaced have no problems. Without a scan tool, you could spend a bunch of money hanging parts, and never get it fixed.