Does anyone know what could be causing idle to rise some 200 rpm - i.e. from
the usual 800 to some 1000 - when car is warm? If I leave the car idle it
rises itself, but if I push and release the accelerator just a notch, idle
is back to normal, then if left to its own devices for some seconds, idle
will suddenly and for no reason rise slightly once more.
I remember the throttle body was a real nuisance to align when I had the car
chipped. Plugs were replaced to no avail. I'm still running the stock '98
BPV. MAF has never been replaced.
Mileage is normal, idle with a cold engine is fine and rock solid stable.
The only other thing is some slight surging at WOT in 5th. At throttle a
little over 3/4, there is a very thin band where boost seems to be getting
on and off all the time when engine is coasting a slope and surging is very
obvious then but at WOT it is very much less noticeable.
Thanks in advance,