I own a '94 850 Turbo and while driving today the engine check engine light came on and the engine suddenly went rough and stalled. I hobbled home (after 20 restarts). I checked the fault codes and got only a 1-2-1 MAF code. I disconnected the MAF and restarted the car. It did start but ran rough, same as before. I understand that if the MAF is the problem, disconnecting it will eliminate the rough running. I checked the plastic bellows air hose to the turbo and it looks OK as much as I can see. I'm not seeing any vacuum leaks but I haven't done a extensive search. This problem came on suddenly.

Thank you in advance for any help.

Steve (That really is who I am claiming to be because it really is who I am.)

I would try to reset the light and disconnect the battery for about 20 minutes and see if the idle is still rought (same as before) with the MAF connector unplugged. If this is the case then it could be several possibilities. One being the fuel filter if all hoses check out...make sure none of the hoses got blown off, including the charged air hoses to the turbo (one being on the driver's side at the bottom next to the radiator (90degree 2.5 inch diameter hose). Also, it could be that your throttle needs cleaning badly or you're experiencing some electrical issue such as bad igintion wires. If the car idles fine (still will set the MAF light if it's disconnected), then it really is your MAF.

I just went through this recently with my S70...but disconnecting the MAF connector let the car idle without bucking or dying, but as soon as I connected it up, my car would die, so I replaced it. I didn't have time to dilly dally around, so bought one from my dealer...a $205 part, but they gave me a discount and I got it for $177...still high. www.fcpgroton.com has the Volvo part for about $168...and after market part for about $20 less. You might also check some salvage yards. I could have bought one that would have worked on my car for $60, but I wasn't sure it would really fit, so I passed it by, later to find out it would have worked fine. Anyway, good luck with it and report back what it was.
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1998 S70 T5 Emarald Green Metallic, 2004 V70 2.5T Ruby Red, Previous Owner of Black '94 850 Turbo Wagon. My cars have been running so well lately they've got me worried.

Thanks for the reply! Well here's what I did. I cleaned the contacts on the MAF and connector, disconnected the battery for 30 min., reconnected and cleared the 1-2-1 code and started the car with the MAF disconnected. It ran rough. I thought it was something other than the MAF at that point. I then reconnected the MAF and restarted. It ran GREAT! It looks like the problem was with the MAF connector. This car does not like to run without the MAF connected. Thanks again.

Steve

That's sort of opposite of how my car reacted, but then again, our cars are different. Glad you found the issue...I hope it's just the connector. On mine, cleaning the connector had nothing to do with my problem. Have you seen this...if you haven't done this already, you should:
http://www.volvospeed.com/Repair/maf_secure.php
Regards,
MIJ
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1998 S70 T5 Emarald Green Metallic, 2004 V70 2.5T Ruby Red, Previous Owner of Black '94 850 Turbo Wagon. My cars have been running so well lately they've got me worried.