engine surging on start up

[Mr.FixitNorm]

Hi All,

For some time now I've had an odd problem when starting my car from cold, the engine starts readily but imeadiately surges with the rpm going up to about 1500rpm then down to about 800, as I pull away I have to over-rev it a bit to stop it stalling. As I get to the end of our road, I dip the clutch as I stop and the revs almost die to nothing, then bounce back, within another 2-300yrds this `fault' disappears and the car drives and idles normally. I've sort of got used to this and sometimes allowing the car to idle for 30-45secs before pulling away will prevent the `surging for the first 1/4mile.

Any tips about where to look first ? is it the dreaded DME relay?? It only a happens when the car has been standing overnight during the day once the car has been started it restarts and runs perfectly.

Cheers,

Norm

 

[sulzeruk]

Fuel pressure regulator or damper is not doing what it should by the osunds of it,
Alasdair

 

[robwright]

Agree with Alasdair but could be the ISV also I guess. Sounds a lot like Andy hairyarse's problem.

 

[924nutter]

I have read that wear in the bearings of the air sensor metering plate, which I believe is of the barn door type of plate, (connected to the output potentiomenter?) can cause erratic idling when the engine is cold. Ithink I read it somewhere on this forum somewhere. Or, does the 944 have the hot wire air mass sensor like later 928 models?

 

[robwright]

It's a barn door mate.