Alfa 156 2.5 V6 throttle/rev problem
My 156 2.5 V6 has developed a strange problem. I noticed it first when after it had been standing in cold conditions (but nothing serious) for a couple of days. There seems to be a problem with the throttle. If it is fully depressed the revs will not go over 4000, however, if you let off a little (so it is only 2/3s depressed), it will go beyond this and happily rise to around 6000-7000.
The garage had a quick look at it and gave everything a good clean, but without testing the electrics fully (for which they don’t have the proper kit) couldn’t find the problem. It has just been through a full service, and after hitting the wallet hard it would be nice if I could find the problem without sending it to the dealer.
I have stuck in a new MAF, reset the ECU and then separately reset the throttle. This has not made any difference; does anyone have any ideas what a likely list of problems could be?