1996 Volvo 850 Turbo Rough Idle and Stalling When Warm

[jonesboy1983]

My 850 turbo otherwise is running great but after it has warmed up, for example after I have driven and the freeway and then come to a stop at a light, the RPMS will drop sometimes, and sometimes the car will stall. This will happen intermittently. If I keep my foot on the throttle a little bit I can prevent the rpm drop and stall. After the stall, it will start back up pretty rough but then it will stabilized until the next stop. I don't have any codes.

Last week I replaced the cap, rotor, and wires (spark plugs had been changed 10k miles earlier) and I thought that had fixed the problem but then it returned yesterday when the weather got into the 80s again. I tried unplugging the MAF but the car ran worse and stalled. Yesterday I replaced the IAC valve but doesn't seem to have helped either. Not sure what else to do at this point. My next moves were going to be to clean the throttle body and replace the fuel filter. Anything else I should be looking at? Thanks.

[Vovo_merz]

I had a very similar problem on a S60 and turned out to be MAF going bad, the car acted weird and had different symptoms but would always lead to jumping RPM and eventually stalling

[jonesboy1983]

Looks like it was the fuel filter. I also had some pretty nasty vacuum lines going to the TCV but the fuel filter looked like the original with the masking tape on it and car has not had any stalling or rough idle issues in 2 weeks since I replaced.