Re: Eratic Revs
Just been and cleaned out the crankcase vent valve (which was a bit mucky) but problem still persists. Been testing it a bit and found that when you start up it seems to start at about 1300 revs then drops to about 900 or so and stays that way until it gets either warm, or you rev the throttle. Then it starts behaving peculiar, and the revs seem to get as high as about 2800 before there's a slight shudder and they drop back to about 1200, only to immediately climb back up to 2800, and drop again. This makes me think it's the lambda as the change in behavior could be due to the settings changing from rich to lean mixture.
This repeats itself and conspires to make me look a right *** when sat at traffic lights and people think I'm sat there revving continually.
It must be either the throttle settings (drive by wire throttle BTW and no idle actuator) or the Lambda. Don't think it's the MAF as unplugging has no obvious effect except to light the display up.
Just a quick question, do you think cleaning the throttle (first with AC90 maintenance spray, then with proper carb cleaner) could naf the lambda up? The first spray doesn't contain any silicone but I'm thinking it may contain something else that could affect it, or possibly that the cleaning out flushed some garbage through into the lambda. Maybe it was on it's way out and this just accelerated the process.
< Rob >
Spider 2.0 TS 1997
156 2.0 TS Selespeed 1999 (now sold)
147 2.0 TS Lusso 2002