Might need a video to explain this. But ever since my race 783 injector fit, the car has always had a missing sound, like it's running on 3 cylinders. This occurs between 1500 and to a bit above 2000rpm. It doesn't smoke when missing, but I did notice that when I just rev the car up in neutral, the missing is real bad and there is quite a lot of white/light grey smoke coming out the exhaust. It doesn't smoke on tickover, and doesn't smoke at all when just driving normally, even when it is missing.

I've been told before that one of the injector units could be faulty. Would a leak cause this white smoke effect? Oil isn't being consumed faster than usual, water is clean and clear. And when power is wanted, the missing disappears and the car fires on all 4 cylinders, giving the usual real strong power.

Up to now I've not been bothered due to it running well under WOT, but with my MOT due inside 4 weeks I am a little worried about the smoke test done on idle...

If one of the injector units is out of whack you'll get the ASR light come on, and a scan done while idling will show it up. (based on a nasty personal experience )

The scan shows the injection quantity for each injector, and if out of range the above happens...

HTH mate

Bas

I've had nothing like that (thank god! :eek: ) No fault codes in the engine section except the usual EGR one.

In that case, maybe something else is amiss elsewhere which is causing the misfire at this specific rev range? I have noticed also that the tickover is not rock steady, but I think that is just symptomatic of fitting race injectors in the first place, not helped by my ultralight flywheel?

What I do know mate is that tuning bigger injectors is a dark art. Shifty had all sorts of problems till Richard Washbrook did his.

Rich said that the scaling is tricky with bigger injectors (whatever that means).

I know that the ECU goes senile once in a while and needs to be disconnected for 10 minutes while warm and then thrashed to get the optimal adaptation....

Glad to hear it's not likely serious.

TC

Bas

I had a problem with my PD engined Golf where the wiring loom that runs through the head to the injectors went faulty. It would run on 3 cylinders until it warmed up and then clear. The loom is about £30 from the dealer and fairly straight forward to fit.

Mine's like it all the time so I have ruled out that wiring loom strip thing (for now )

I will get a video up at some point.

Get vag com on it and check injector quanities when its running and missfiring, it should tell you which one is having issues.

I had similar problems with the skip, and it was driving me crackers ( well, more crackers...).

I put a bottle of injector cleaner in the tank, ( Wynns I think ) and it cured it.

I know that these 'snake oils' are anathema to some people, but it was a cheap and quick attempt at a fix, and it worked.

HTH

mr grumpy has suggested the first thing i thought of and that is to get some injector cleaner through the system. just wondering if you have water in the system and its blocked the jet?

wouldnt water just be pumped through or am I missing summat??

water molecules are bigger than fuel molecules and can block up injectors. what im guessing here is a bit of condonsation is rattling around an injector but cant get blown through, thus an injector cleaner or water remover from somewhere like halfrauds should see to it.

I use millers diesel sport 4 religiously, which I would hope would clear any gunk and keep the injectors in good trim. However, if one of them wasn't put together right, no amount of cleaner is going to cure that. Annoying really as I paid £100 to have all 4 injectors bench tested at a diesel injector specialist up north, and the results were all good. :(

Sounds like a mechanical fault with the injector which may not be picked up by vag com. If the injector is not atomising the fuel properly then with no load you will notice the smoke but when you drive it with load it will burn it, but then injector people should have picked that up......

rats - looks like I might need to look into getting a set of pd130/150 injector units and get uprated nozzles fitted somewhere properly.... Or rip my current ones out and send them away which means time off the road for the mongrel. :(

Make me an offer, Ross has a full set of mine

If logging injector quantities proves something is wrong, then I shall get on to you Wiebo.

I noticed today that it smokes worst trying to keep it at a steady revs, eg 3000, such as for a trackday sound test. If I hoof it up to the redline, it's not as bad at all.

Make me an offer, Ross has a full set of mine

So surely he would ne making me an offer

I would have though that the pressure injectors run at would clear

any condensation :confused:

So surely he would ne making me an offer

True, however it would be good to get a few more bits flogged

How clean is the air filter Jason?

How clean is the air filter Jason?

probably needs doing soon, but is not related to the current running issues. The car is throwing in and out of charge pressure control deviation limp mode at the moment, but I know why that is.

White smoke is unburnt fuel.......maybe poor spray pattern from one nozzle?

I have just found this about MOT's, what is tested and why it would fail on.

MOT UK car and vehicle MOT information