I have a project 2000 986 2.7 and I'm chasing down a rough idle and rich smell of petrol when running.
Initially it ran much better with the MAF disconnected, however I also noted a lot of oil in the plenums and even on the throttle body.
So cleaned all that up and replaced the AOS.
Now the car idles much smoother but is still not right.
With the MAF connected or disconnected there is not obvious difference.
I can't find or hear any vacuum leaks.
I'm now leaning towards the pre-cat oxygen sensors.
The voltage on both looks to be within range at idle, but I'll remove them, check how clean they are and the resistance across the pins etc.
I do note that when I rev the car the plenums on the engine almost look like they are 'breathing', by which they seem to almost swell. No idea if this is normal.
I am wondering if my throttle valve, which I have cleaned and it moves fine, is faulty and not letting enough air in, or perhaps the MAF is faulty. It looks like the throttle body valve never opens more than ~20% when revving the engine.
I know there could be several things at fault here but welcome ideas.
No error codes or EMLs.
Should I consider replacing the MAF, after I have checked the oxygen sensors are not blocked?
What else could be causing what smells like a rich mix?
No smoke.
Thanks.
Linear Mode
