2.5tdi leaking injector cuase misfire?

[leock]

Hi guys :)

My 2003 2.5 tdi avant started having a few misfires/ rough running a while ago, one night j noticed it, stopped at roadside, turned engine off and on and fine. It did it like that a few more times and going into limp mode a few times until the glowplug light started flashing.
Noticed today that there is leaking around one of the injectors. Can this leak cause the rough running/misfire?

Used a cheap blutooth obd2 which connected fine but didn't read any fault codes.

Hoping this isnt the pump as cant afford to have that repaired at the moment.

Many thanks guys

Leo

[old guy]

A small amount of leakage around an injector (as in you can see some wetness but no actual flow) is not going to cause a misfire.

[diagnosticator]

Are you able to estimate how much the injector is leaking? More than just damp around the injector, actually wet and leaking down the head, or not? If it is more than just a light dampness, the loss of internal injector pressure will possibly prevent the injector from opening properly at the correct time, and that would cause at least a partial misfire. In any case, injectors are not allowed to leak even a little, leaking injectors must be replaced.

[leock]

Thanks guys, yeah it's only something i recently saw and going to source it asap, looking at doing it myself if it's not too tricky. It's more than dampness, it's a small dribble/flow,here are some photos, you can see if runs down to the edge and pools there.

[diagnosticator]

Make sure the rubber return line connection at the injector is tight. Loose return lines are typical places for leaks. New return lines cut to fit is recommended. If the return line is leaking, that cannot cause a misfire due to injector pressure loss.

[leock]

Thanks, the rubber line doesnt appear to be the leak, it seems to be coming from point of entry into the head, not dribbling down from the nut, but will get a closer look this afternoon with my spotlight

[diagnosticator]

Thanks, the rubber line doesnt appear to be the leak, it seems to be coming from point of entry into the head, not dribbling down from the nut, but will get a closer look this afternoon with my spotlight

Wash the area with solvent and hot water, then dry thoroughly. Then observe the injector with the engine running to identify where exactly fuel is leaking from.

If fuel is leaking from the injector hole, around the injector, then the injector must be pulled and replaced. If the line nut is leaking, loosen then re tighten the line nut but do not over tighten! Use a wrench on the flats of the injector body to back up and oppose the tightening torque applied to the line nut, to prevent twisting the injector in the hole, or twisting the high pressure fuel line to the injector.


In either case above, can cause misfires. If leaking from the return rubber hose, cannot cause misfires.

[leock]

Many thanks, will do that this afternoon and let you know how I get on.

Cheers

[diagnosticator]

You will get it sorted out. BTW, it is definitely not the pump, so no worries there.

[leock]

Back again,had a loonngg day but that didn't stop me getting out in the dark to give it a go..

so it after giving it a good clean it has turned out to be the rubber hose, started to drip after about 5 mins.

Also there was no misfire, smooth as a kitten, the flashing coil light is still there and also the triangle symbol.

I guess if it was the pump it would be a more constant problem?

What could cuase a random misfire and the coil light, which is also an engine management light isn't it? I guess i'llhave to take it to a garage to see if their vag-com will find any codes, i assume the cheap obd2 readers arent too reliable?

[leock]

I've been wondering if i'm correct in saying it's a misfire? I've not experienced one before! It sounds like the engine is running rough, you ca feel it rock in what seems Un ueneven running? Would that be a misfire?