Engine Surge

[Steve F]

My '01 has developed an engine surge last week that becoming worse. I bought the car last August, I just turned 180,000 miles. The car has had a rough idle since I bought it, where it searches for an idle rpm. Last week, it started getting a little difficult to start, would misfire a few seconds as if the fuel pressure had drained back overnight. About the same time I noticed a surge while driving and it's becoming more erratic the more I use it.

There are no codes or messages showing.

[Astro14]

Start by pulling the throttle body and cleaning it. Then clean the MAF using MAF cleaner only.

Then see where your driveability/idle is...

[howardc64]

+1 to Astro14's comments.

Failing MAF and throttle body often don't produce codes. Pain to debug.

On MAF, I've had to swap with a good one to confirm it was MAF failure. Cleaning didn't do it for mine failing MAF.

On Throttle body, cleaning is a few hours of work for first time DIY. Volvo's diagnostic tool (VIDA/DiCE) does have a ETM sweep test to check for error. Might be helpful if you have access to one.

[Volvoholic]

If the MAF doesn't work, you could always try injector cleaner although clogged injectors wouldn't give you such bad issues...unless they're really clogged. Some Techron in the tank and maybe some seafoam would help to clean it out under there also. Not sure how well seafoam works in Volvo engines though.

Considering your car is an '01, could also have a TCM or ECM reflash available to you, but you'd have to call the dealer about that.

If none of that works then into the dealer it goes. But I'm 90% sure your MAF is bad. Maybe 80% of the time I hear this problem, it turns out to be a bad MAF sensor.