w211 e220cdi rough idle when cold

[haydar]

As the weather is getting colder, my e220cdi has started to idle very rough in the mornings. At the same time it's blowing out loads of white smoke from the exhaust. Then 2+ minutes after start it all clears up, idle becomes smooth and no more smoke from the rear.

Using the STAR diagnostic system, everything seems fine except the MAF and injector quantities, which are both high. This points to unburnt diesel being the white smoke as apposed to engine oil. I think is confirmed by the fact that the car does not consume engine oil.

Now even when the car starts to idle normally, the MAF is still over reading. I've replaced the MAF several times and it always over reads!

What could be causing this??? If there is a air leak in the fueling system, wouldn't that be there constantly and not only for the 2-5 minutes after first startup in the morning? It could be the injectors but they were replaced.

There is the posibility the car's ECU has been reprogrammed, so I've tried reprogramming the ECU via the STAR system but I keep getting a 'communication error 8.600'!!! Anyone know what communication error 8.600 is??????

Thanks

 

[Parrot of Doom]

Sounds like exactly what happens when glow plugs stop working.

 

[haydar]

Is there a test for this?

 

[Ellsy Tanners]

Yes, test the wires to the glow plugs from the large plug that comes out off the glow plug relay on the n/s front wing. they should all be about the same resistance, 0.5ohms if considerablly higher or open cuircut then its faulty. the number on the plug refers to the number cylinder thats faulty! hope thats ok to follow!!!

 

[haydar]

I'd love a diagram .... but thanks for the advice and I'll give it a go.