Misfire and other faults

[andyg plym]

Evening chaps, well I can't begin to tell you all how surprised I am at reporting I have a few faults to attend to - in the last 2-3 years the colgate wagon has been fantastic with hardly any issues at all! Some of you may have seen I have recently moved house and typically when I have now garaged the old girl she has decided to throw a tantrum!

So, for a little while now on cold start up it slightly misfires and after about 5 seconds it clears - I had put this down to the fact that one of the veins just inside the RS2 exhaust manifold was cracked - internally as you look through the turbo side flange but now the misfire is permanent.

Tonight I had a fiddle around and it appears number 4 injector is not working. I have checked for power and all 5 injector plugs are giving 12.5 V with the ignition on, thought I had read it should only be about 5V ? Norbitron TFSI Coil conversion set up and swapped coils etc first but the problem stays at number 4 when unplugged with engine running. Spark plug also checked - all ok. Unsure how to check an injector without swapping so thought I would carry out a continuity test whilst there and all 5 were the same.

Connected to vagcom and got fault code 00553 - Mass airflow meter signal too low. I even repeated the test with number 4 injector plug disconnected and still it only came back with this fault code. Tried another known working airflow meter and still the same. Appreciate this could be a red herring as it could be the result of a boost leak (not yet performed), faulty Lambda (been in about 2 years-fuse also ok) etc

Anyone else had this before?

Cheers

[UrS4boy]

One missing and hestitation diagnostic procedure

I don't like the way you did your diagnostics. Try reading this:

One missing and hestitation diagnostic procedure:

http://forums.quattroworld.com/s4s6/msgs/22611.phtml

[andyg plym]

[QUOTE=UrS4boy;926060]I don't like the way you did your diagnostics.

Sorry to hear that

[Error404]

Injectors have 12v supply, the ECU pulls to earth to trigger the injection event.
Sounds like No.4 injector may be faulty or more likely the wiring or connector are crumbling
I'd try disconnecting the injector and seeing if you have any change, also try an output test on the injector

[andyg plym]

Injectors have 12v supply, the ECU pulls to earth to trigger the injection event.
Sounds like No.4 injector may be faulty or more likely the wiring or connector are crumbling
I'd try disconnecting the injector and seeing if you have any change, also try an output test on the injector

Cheers Alex I did pull the injector connectors whilst idling and the only one that made no difference to the rough idle was number 4. How can I do an output test bud ?

Dave just read your attachment and yes a compression test due to a burnt exhaust valve could be in order- it runs 1.9 bar boost so maybe I have been pushing my luck

[andyg plym]

Ah Alex you are talking about a test on vagcom? ****** I only have an old cheap Chinese version !

[UrS4boy]

[QUOTE=andyg plym;926063]

I don't like the way you did your diagnostics. Sorry to hear that

In future, I won't bother to comment/try to help you then. No problem.

[macspring]

Dave,

Different sense of humours.

Everyone appreciates your help.

[andyg plym]

[QUOTE=UrS4boy;926068]

In future, I won't bother to comment/try to help you then. No problem.

If you were intending to insult with your comment you certainly achieved it. My intention was to ask for help not an argument. I don't personally think I did too bad in narrowing my fault down thanks.

[macspring]

aah Andy ffs.

Stop !

This is gonna go no where good.

One's ego need to be left outside, they have no place on here.

[andyg plym]

Correct it won't go nowhere good but at the same time I'm not going to sit here and take that, almost as if it was right on cue. Just for a change im going to stand up for myself on here. Don't have nothing good/ constructive to say then perhaps just leave it.

Actually found that remark quite offending.

[macspring]

I see your point and can empathise, but I also see the bigger picture, you wanted assistance in determining the fault with the car.

Certainly not wishing to take sides or diss anyone, but I know you've been on here long enough to know what Dave is like and how best to communicate with him.

See previous rows for reference.

Sure we all have our foibles, ask my wife if you have a full hour to spare !

or pm macanmar.

Peace to all.

[Rusty]

Best tool for troubleshooting is a hamme, isn't it? A good whack will fix your ailment(s)!

send the injectors off to get cleaned and tested. I think Will at VRS did mine and it was about £15 per injector. You get all new seals and so you'll know there all sorted. Co tinuitt on the injectors from the ECU plug. Check the limits on s2central

[andyg plym]

Thanks for the comments guys, tonight I swapped over injectors and can confirm the fault didn't move so injectors appear to be good so the fault would appear to be something else on number 4, I have fuel, spark so I'm thinking next could well be a compression test and see where I go from there whether it be a defective valve or head gasket.

[Error404]

Same rude individual upsetting people again i see

Check the injector connector and wiring harness in that area Andy, very common problem and I'm yet to see an original harness that doesn't need some attention!