Poorly 1.9 PD

[philipharmes]

A friend asked me to have a look at his non starting 1.9 PD today.
He said it had been driving ok, then all of a sudden started running rough.
He drove home & parked, but the following morning it wouldn't start.
Another mate who lives local sprayed some easy start & got it running, but still very rough, then wouldn't start again from cold.
I went around this morning & plugged in my VCDS, the only faults showing were no communication with ABS or A/C controllers & turbo over pressure.
Noticed the coolant temp was at -6 degrees so disconnected that, it then showed +15 degrees which was the same as the fuel temp sensor, but still wouldn't start.
When trying to start it sounded like it was firing on one cylinder only.
We tried easy start but still no joy. So I towed it & it started straight away, but lots of black smoke.
Connected VCDS again while running & when showing all four cylinders injection quantity, injectors 1 & 2 showed +2.99 while injectors 3 & 4 showed -3.01.
So from that I concluded that injectors 3 & 4 must be failed.
I tested the injectors electrically from the socket at the end of the head & all 4 were showing approx 1.2 ohms resistance.
At the moment i've suggested to him that he renews the injector wiring loom first, even though it seems to test ok with my meter.
Then change the 2 injectors if still a problem.
I've never had a problem with any of the injectors on all 4 PD Passat's we have had in the family, so would appreciate comments from anyone with previous experience.
Do you think I have come to the correct conclusions?

[zollaf]

a new harness would be a good start, but it won't be that, they never fail like this. when was the fuel filter last changed, is the intank pump running and hadhe just filled it with fuel ?

[philipharmes]

Thanks for the prompt reply.
The fuel filter looked old, but the first thing I did after it failed to start was disconnect the fuel outlet from the filter.
When I turned on the ignition I got about 50ml of fuel spurt out into a bottle, which I thought maybe should have been more, but proved that the pump was working.
The fuel level was low, 40 miles remaining showing on the computer.
Also took off the rocker cover & noticed that most of the injector loom plastic trunking was missing.
That was another reason to renew the loom first I thought.

[philipharmes]

The injector loom was renewed, but as zollaf predicted, made no difference.

I can't really believe that 2 injectors would fail together, but am thinking that due to running low on fuel, some crud has possibly got passed the filter & clogged them.

I'm also not sure if my original thoughts were correct, in that it is cylinders 3 & 4 that are down.
If VCDS is showing cylinders 1 & 2 as +2.99, is that because those 2 cylinders arn't working, so the ECU is trying to run them at maximum fueling?

At the moment I am suggesting he changes the fuel filter & runs the engine with some injector cleaner.

Would appreciate advice from anyone who has experience of similar problems.

[adamss24]

Take the rocker cover off again and look at the camshaft lobes, pay attention to worn trough tappets. If easier, jack car up from one wheel then spin the wheel in 6th gear- will make looking at the cam easier... Cambelt IF slipped will also have a similar outcome...

[philipharmes]

Thanks for your suggestions.

I did run my finger around a couple of the cam lobes which seemed to be smooth, but didn't look at the tappets.

I had checked the cam belt.
He had it renewed 6 months ago together with the tensioner & water pump & the belt was tight, so I couldn't see that it would have slipped, but havn't checked the timing.

So I will suggest those to him.

[Col]

Sounds like fuel starvation and also sounds like the tandem pump has given up.

[philipharmes]

Interesting that you suggest the Tandem Pump.
He initially brought the car over to me about 3 months ago in permanent limp mode & poor brakes.
I initially checked the vacuum which was very low.
Traced the problem to a loose flange connexion on the Tandem Pump.
Bodged it with some sealer which cured all his problems, but suggested he get it renewed.
It turns out he fitted a second hand replacement which maybe has a poor fuel pumping section.
So will probably suggest he tries the old repaired pump if he still has it.

[Col]

A new metal gasket and or 'o' rings depending on which tandem pump is fitted are critical as well if you want to prevent air ingress, bad starting and rough running.