E300td intermitent fault

[R Phillips]

1999 E300td, car runs fine for 99% of the time but every now and then on start up I get a small rumble of a missfire, when this happens the car then has no power. to drive, it feels as though only the first 20% of the throttle is working. The engine sounds fine but is down on power. It has never cleared while on the move, but after it's been left on restart it tends to be fine again. It happened about 3 times in the first 5/6 years (I've had it from new) but now seems to happen more often.
Any ideas?

 

[Parrot of Doom]

Hi there. Try giving this a go:

http://forums.mercedesclub.org.uk/showthread.php?t=18298

 

[R Phillips]

I have cleaned the MAF, but would this be intermitent? it only happens once a month or so.

 

[R Phillips]

Just gone again after 3 months, fine from a could start, power goes just before reaching normall temp (about 70 deg)

 

[Parrot of Doom]

Underneath the air filter is a small black cylinder, an actuator valve for the turbo. Exactly the same device exists near the ABS pump on the other side of the engine and controls the EGR valve. You could try swapping them over, but first check that all the vacuum pipes are connected properly, and leak-free.

 

[R Phillips]

Thanks found them ok, looks simple enough to swap over.
What do they do ?

And that should have read "cold start" above.