Hi, I hope that no one is mad because I opened a semi-dead thread.
Firstly, I read through this whole thread, all 7 pages off it.
Secondly, the problem I am experiencing is similar, but not exactly the same.
For a good description, please see the thread I started here:
But in short, my problem is when slowing down to stop car, as soon as the revs hit idle speed when I clutch, the revs go down to about 400 RPM, then back up to about 1000 RPM, repeats this cycle about 2 times, then return back to "normal" idle at 900 RPM.
This first started happening about a few days ago, after I got my car back from repairs at the service centre. It wouldnt start. After replacing the Crank\RPM sensor, they found a dead/loose connection wire close to the ECU, which was the actual problem.
So the difference between the problem described here and mine is that my engine doesnt die, or jerk. And the problem is only with idle. Driving otherwise no problems at all. Also when just leaving the car to idle at standstill, it is idleing nicely at 900 RPM. So its only when slowing down and clutching, but I also get the problem when just revving in neutral. So it seems like its battling to get to the right idle RPM ONLY coming down from higher revs, and it does not do this when the car is cold. But 2 minutes driving sure as hell it happens.
Here is what I have done:
1. Reset ECU by dcing battery for more than 45 mins, starting an idling for 15 mins.
2. Resetting the idle (90 secs on and off trick)
So I suspect the idle motor, MAF sensor or the lambda sensor to be faulty. I am also considering cutting that wire behind the speedo. Though I would prefer to spend money to replace whatever is the real cause, even if it costs more, as long as I dont have to take the car to the dealers.
O car is a year 2000 model 156 2.0 TS.
I hope with all that detail someone can help me narrow down the problem.