Hi. I'd appreciate any help with this. My 2001 S40 Turbo drives great (I recently drove it from NY to OK), but it stalls sometimes when I brake at a red light or stop sign, so I put it in neutral then. The check engine light was on the entire way back and forth to OK, and it never stalls when I'm driving, only when I stop. Sometimes I have to pump the gas pedal to get the car to go after a stop. I have no other problems with the car, and I'd really like to fix this, but I'd like to know exactly what the problem is before I bring it to a mechanic. Before I left for OK, my mechanic friend changed what I think is the Idle Air Control Valve Hose, but they didn't have the Volvo hose, so he rigged it up with another hose. Since then, the engine sounds different when idling. Other than this problem it's a great car with only 133,000 miles on it. Any help would be greatly appreciated. Thanks.

 

first thing to do is fine out what CEL codes have been set. that will clue you in if you are rich or lean at idle, have an intake air leak or something similar. Next you can spray some carb cleaner around the boots and hoses and look for torn vacuum lines. Finally you can use some MAF cleaner to clean the intake -ie MAF/throttlebody/idle valve (that round cylinder off the right side of the intake manifold)

 

Thank you. I'll see if that works.