Bought last weekend thinking it needed a new fuel pump. Got new fuel pump it starts then stumbles and dies. Previous owner said wife was driving and car started bucking and loosing power she pulled to side and it died. He got it home but then couldn't get it started. He thought it was fuel pump also. we replaced filter and line going from pump to fuel filter. at a loose and thinking it might be MAF? We unplugged MAF and it stalled and would run the same way it did when plugged in. Put about 7 gallons in tank, just in case it was out of gas, no help. No codes, battery on charge, dead. Any suggestions? Have a blessed day!!

 

You need a good scan tool to read data. At idle, there is a reading of how much air is coming across the MAF sensor. It is probably much different than actual due to the insulating quality of dirt and dust accumulating over the years.

For a no-cost repair attempt, use the correct type of cleaner to spray in the MAF metering window. Then, remove and clean the throttle body, both sides. You want both sides gleaming so that any airflow going through that thing goes smoothly. I've seen Volvo cars that we buy for resale that wouldn't idle properly and give poor throttle response come to life after a good throttle body and MAF sensor cleaning.

 

+1 on getting codes read by a quality reader and the cleaning mentioned above.
You said, "We unplugged MAF and it stalled and would run the same way it did when plugged in". Would it start then run badly then die? I'm not trying to be difficult here. Your description isn't clear.

Additional random thoughts.
How many miles on this car you bought? Please include this in any post about any problem.
Did you do anything else to it?

Check the incoming air hoses. They can split and create problems.

 

Sorry for leaving this post so long. Way to many irons in fire. It has 280,000 miles on it. We took throttle body off and cleaned it, put it back on, then turned key to let it reset, it never quit resetting itself which leads me to believe the throttle sensor needs replaced? I know they make a kit to replace some, but didn't know if for this model. After cleaning throttle body the car would at least start and stay running, but it kept trying to reset or calibrate while running I think, meaning it would reeve up and down. Short term fuel trim went below -10. throttle position sensor didn't stay in place, idle wasn't steady. MAF gave reasonable numbers 1.1- 1.3 I think up to 2000RPM since it seems to be in limp mode. My son wants to park it out, I hate to do that since it seems like nice car. Thanks a big bunc for addvice and help, hopefully I can someday figure things out and help some of you guys. Have a Blessed Day!

 

Aanyone have any other advice?

 

I had the problem with my 03 2.4 turbo stalling out, I replaced the MAF and it was good. Also have had a few vacuum issues after that, problem was similar - check the lines. And have you gotten any codes? If it's p2188, there is a good guide here to fixing it and other common issues -
Curing a P2188 Engine Fault Code on my Volvo S60 2.0T - Updated 24/11/2012

 

Seems like the throttle body is trying to reset to zero. It seems like it is terying to reset even when it is running.

 

Mine's been hunting a bit at idle and not liking high rpms. It was stalling before I installed the MAF AND 02 sensors. I have to do pcv service and throttle body this weekend, I have replacements for both. I also have a MAP sensor, which is unlikely to be the culprit, but as the other two are replaced might as well finish the closed loop. I'll let you know how it goes if you haven't fixed your issue by then.
Also, even if unplugging MAF didn't do much, try taking it off and cleaning it along with your air box. Shouldn't take very long, but make sure to use MAF cleaner on the sensor. And still you should run codes at an autozone or local mechanic, or even better a european car shop. A lot of them are pretty telltale and a many people know fixes for them.