Hey Guys,

I am purchasing a cherokee and I found a '99 (the year I have been searching for). It is in decent condition for $1000.

The owner says it has an open ground on Injector #4. It misses on idle but is fine when it gets moving. For $1000, would you advise me to keep looking?

Based on google results, it seems somewhat common that the pigtail will take a crap and short out. Thoughts? I would very much like to not have to dig through electronics, I'd rather drive toothpicks under my nails.

Thanks in advance for any help.

 

if you have any experience working on a turbo surpra..

that code shouldnt be anything big..

have fun haggling

 

Is not a ground is the PCM,Must be bad.
The PCM will adjust injector pulse width by
switching the ground path to each individual injector
on and off. Injector pulse width is the period of time
that the injector is energized.

 

That's what I have been reading. I am handy and somewhat savvy when it comes to car-work but I hate electronics.

Looks like this could be an issue with the wiring harness (shorted out, or as simple as a plug needing a good cleaning) or a failing PCM, meaning I would need to replace it.

It looks like replacement PCMs are rather easy and plug-n-play but require some data to be flashed to it before they fire up. Can anyone verify this is correct on a '99?

 

The car was zero fun to work on. A blast to drive, but when **** hit the fan.. it was about as fun as aids.

 

Yeah I'd give it a go if the body is in good shape. Wiring problems are common, rip open the harness and you might find that wear over time has either cracked wires or created a short. A simple test with a multimeter should tell you what's up. Beyond that, yes, the injectors ground via the PCM. Shouldn't be impossible to find one from the zillions of XJs lost to rust, though. If it is the PCM then what, a pristine '99 for $1200? $1500?

lmao! Well if your XJ has an auto, it's almost the same transmission

 

Any idea if I need to get the mileage and VIN flashed to the new PCM on a '99?

 

That shouldn't be necessary. It should just be plug and play. The mileage is stored in the cluster, not the PCM.

 

Da, mileage in cluster. Never heard of the VIN being an issue for our PCMs.

Remember, it could just be a wiring harness problem

 

If the injector is shorted you would get a Check engine light,maybe is the injector that is bad.

 

Have you scanned it for codes and had a peek through the oil fill cap?

 

I will be doing both this evening. I was only able to briefly look at the car as the owner wasn't around and I was short on time. I really just looked at the interior and the underside.

Why the oil cap? Check for symptoms of a blown head gasket/cracked head?

 

Here's a list of Fuel Injector DTC codes:

P0201-INJECTOR #1 CONTROL CIRCUIT
P0202-INJECTOR #2 CONTROL CIRCUIT
P0203-INJECTOR #3 CONTROL CIRCUIT
P0204-INJECTOR #4 CONTROL CIRCUIT
P0205-INJECTOR #5 CONTROL CIRCUIT
P0206-INJECTOR #6 CONTROL CIRCUIT

 

When you find out what code is active, or pending, I can post some trouble shooting steps for P0204.