Engine rev's rising and falling when starting

[blocko]

I had trouble the other day with my ABS control unit and the ABS light coming on...... see the thread.... http://www.vwaudiforum.co.uk/forum/showthread.php?t=7813

I took the control unit (ECU) part of the ABS off and have sent it to BBA Reman for it to be repaired.

Now I have another problem...... when the car is first started the engine revs rise and fall until I drive away. Sometimes it starts, then stalls :confused:

It feels like the accelerator pedal is moving all by itself when the engine is hunting :mad:

Is it because I disconnected the battery to take the ABS control unit off, and will it go back to normal when I put the unit back on?

[kharva007]

try spraying cleaner into the air intake pipes???

[kharva007]

or your ecu could be sending wrong signals to your engine

[Huweth]

Are you trying to use the car without the ABS ECU? If you are, that could well be causing the problem!
One cause of engine revs rising on startup is caused by a fuel shutoff solenoid seal that is drawing in air, but I've never heard of it a severe as your symptoms so that might not be the problem in this case.
Don't use your car if the ABS ECU isn't fitted.