Hey guys,

I've had an ongoing issue with my 2004 TD4 that I have attributed to worn injectors.

First start of the day would have you think that a tank has let off a smoke screen there's so much white smoke. It doesn't smell oily so I figured it's injectors leaking overnight. Engine idles fine but is lumpy and slow to rev until the smoke clears, then it's down on power and rattles until boost comes in at around 2k revs.

Today I carried out a leak off test to find absolutely no leaks from any injectors. I disconnected the MAF and the engine now revs properly and gives off black smoke at full throttle.

Whilst doing the leak off test I noticed that when the fuel pump is priming there is a hissing / radio static noise from the fuel pipes attached to the block behind the radiator. I also noticed some slightly perished fuel pipes so could air entering the fuel system here cause a clackey engine? As I say it idles fine but is just noisey!

Also, am I OK to simply drive around with the MAF disconnected?

Cheers, Paul.

It's unlikely to be an air leak in the fuel pipes as they are under pressure from the low pressure fuel pump.
Have you looked at the live fuel pressure data?
Driving with the MAF disconnected will loose you MPG but otherwise it will be fine, on a temporary basis until you get a new MAF sensor.

Thanks Nodge. Is there somewhere that air can get in either before or after the pump and cause cavitation in that general area? It sounds like white noise and is coming from the 90 degree hard line where it turns up towards the injectors at the front of the block down by the oil filter. If I pinch the rubber fuel line that connects it then I can change the sound.

I haven't checked fuel pressure. Was going to order a Hawkeye. Is this the best unit for the job?

Cheers, Paul.

It's possible for air to be sucked into the fuel before the pump under the driver's side rear arch liner.
I have an Icarsoft I930 which shows pretty much all that is needed on the TD4. However I'm pretty sure that most live data is available using a generic OBD2 Bluetooth dongle and an app call Torque on an Android device. Both of these are much cheaper than the Hawkeye.

I have one of those bluetooth dongle thingies but it cannot show fuel pressures etc.

Have just ordered an iCarsoft LR2 so will see what surprises that throws my way!

Ok so with the MAF disconnected today I moved the car and left it running whilst I grabbed some bits, came back and it was billowing white smoke and idling lumpy. I looked at the exhaust and it was very wet looking. This does not happen with the MAF connected, it just doesn't like to rev and has no power below about 2,200rpm.

Is the MAF not borked but in actual fact compensating for some other issue? Hopefully the LR-II will shed a little light when it arrives, but is it possible that at least one injector is knackered but just doesn't leak out of the top?

Injector over spill or the lack of spill is not necessarily related to a misbehaving injector.