chereveco

Hi here,

My XJ 2001 used to have a very intermittent synth-om, every once in a while when the engine is at normal operation temp, it shuts off a couple of cylinders/injectors...

When that happened I just turned the engine off let it cool and then it restarts fine.

Last week when I was at the line doing the yearly inspection, it started to malfunction, now the problem is permanent. Nice place to fail....

At cool start it works fine, when it gets warm starts the problem again.

C.E.L. shows :
P0202 Injector Circuit Malfunction - Cylinder 2, and
P0205 Injector Circuit Malfunction - Cylinder 5.

If I drive the car in that condition C.E.L. starts to blink.

If I exchange injectors malfunction remains in same cylinders.

If I touch them, they all six feel like ticking, normal state?

So today I removed them for inspection and service, to see what is what at the laboratory.

What else could it be?

Regards,

Cheddarnut

If the code is for the circuit, it can be anywhere in the circuit not just the injector. Start inspecting wires from the rail back.

chereveco

Thanks for the input,

I tested the connectors for each injector, basically with a small light bulb, and they all pulsate at the estimated time...

Cheddarnut

Good call just checking off possibilities.

chereveco

then... what could it be?

autosurgeon

If you have a circuit malfunction code then either you have a bad connection or a bad PCM. You seem to have eliminated the injectors already.

XJwonders

indeed. Happened to my 01. Was malfunctioning like u described and had same trouble codes. Turns out that some of the wiring on the harness above the intake manifold was touching the manifold. It seem to be a common problem for 00-01 Cherokees and all years of WJ

chereveco

Thanks, I will move all my efforts to the wire harness.

Let's see if i get lucky.!!!

chereveco

Input....

Today cleaned all six injectors with ultrasound, and runned all tests...

1 was stucked close at 100%,
2 sprayed at less volume than the others
Remaining 4 did perfect,

After two rounds of ultrasound 1 started to pour liquid, not like the other 4.

2 remained same thing like the beginning.

Changed the 12 o-rings and filters.

Gonna mount them again, all with switched positions and test again what happens at operative temp.

Wish me luck! !!

P.D. Tonight I will order a couple of new injectors from Rockauto.com, just in case.

Regards

chereveco

Injectors arrived, got them installed, engine started just perfect, no C.E.L., it revs fine, no hesitations between 900 rpms and 1200.

Went to inspection and everything is just perfect....

Regards

chereveco

Damm it!!!! Today injector No.6 Blew off... It passed away in a dark cloud of smoke.....

Finally ordered all remaining 4 from Rockauto.com, hope these ones last for a good time...

Regards from Costa Rica

Doogluus88

Ya, sounds like a wiring problem. I once had a persistent TPS code. It would only come on when the engine got nice and hot or if I hit a bad bump. Turns out there was a place in the wiring harness where one of the TPS wires is spliced with a wire from the MAP and then runs to the PCM. The splice had a bad connection and the heat and vibration would cause a poor connection that would throw a code. So i reworked the splice and have had no problems since.

All that to say, I would check the wiring. A haynes manual is helpful...