Someone Please Help

[Spirio21]

Hello All

Iv just about had it with my 2004 BA XR6T....

I took it in to get serviced a week ago and its still at the shop. Basically whats happening is it missing a cylinder when it heats up. After heaps of investigation we came down to the injector. The signal drops off over time to the injector, therefor causing it not to fire.

Changed the injectors, coils and finally the computer, and the problem went away until today...... Previously it was missing cylinder 2 now its 5!!!

Has anyone had the same problem??? and is there anyone with pin outs to the CPU or engine loom??? and last but not least is there any difference from a Ute turbo computer to the sedan???

Thanx Guys

[mic]

could it by any chance be the tps ? I have no idea, sorry if im way off.

[Spirio21]

thanx for the feedback

Unfortunately its not, I changed the throttle body and tps a while ago when I had a similar issue, also changed the spark plugs, coils and injectors..

Everything seems to point to the computer or the loom as it starts off getting a pulse to fire the injector but after it warms up it goes coookoo.. that's why if anyone has a wiring diagram please email it to me so I can try working backwards

[Azzman460]

You have to make sure you get a PCM From the same model car, BAmk1 or BA mkII or BF but it doesnt matter if its from a ute or a sedan. If you've already replaced the computer it could be a loom issue.

[Spirio21]

see that's what I originally thought until the problem moved from cylinder 2 to cylinder 5. I think that if it is a loom problem it would have stayed on the same cylinder???

maybe an earthing problem???

[ETM]

Mine does the exact same thing in the morning when after about 3 minutes of driving, it drops a cylinder, I ake my foot off the pedal and then get back on the pedal and it goes away. Its something that annoys me but I have not looked into why it happens.

[Spirio21]

Then u know my pain

At the moment mine is doing it constantly after start up, but a while ago the it would only happen after I put my foot down, it went away for a couple of months and returned again just recently. Took it to get fixed and its only gotton worse..

[Azzman460]

ok, so how aure are you that its the injector? Have you had the little noid lights on the loom to check the injector is getting the voltage or not? You said you replaced the injector, then the coil then the computer? The problem may still be in the loom somewhere. Bad earth is possible a problem, or maybe the input to the PCM from another sensor is messing it up. I would make 100% Sure you know what the problem is, wether its the injector or something else. Hook up the coils and the injectors to an oscilloscope and scope the wave patterns of them, and go from there.

[Spirio21]

yeah we had the lights to test the injector and the signal starts off fine but after time the signal drops off and eventually dies so its something before the injector. your right, the next step is to use the oscilliscope to check the wave but I want to start from the computer pin outs, thus I need the actual wiring diagram. I would try tracing the wire back but by the time I finish work and get to the mechanic he is about to close so I sort off need a short cut.

[Azzman460]

ok, so the exact same thing happens with the new computer, but on a different cylinder? hmm let me have a think about it and see what I can come up with!