Please help!

2006 XC90 2.5 Turbo AWD

This past winter on one of the coldest NJ mornings, our XC90 started running rough at idle. Believe it or not it's now July and the problem is still present. My friend who owns a general repair shop has tried to diagnose the problem without success. It has not, but seems like it might stall at any given time. Off idle it runs fine.

We have:
Replaced the gas cap
Cleaned the MAF
Changed spark plugs
Tried to check for vacuum leaks (to me that's what it acts like) but without a "smoke machine" it's very hard to see

Anyone have any ideas as to the cause or even the vacuum lines that would have an effect that I could just replace?

Thank you in advance!

 

could be a vaccum hose leak, O2 sensor, could be the mixture is too rich upload a vid i can probably give you a more definitive answer.

 

oh a good way to check for vac leaks get a can of carb cleaner. Have someone help you keep the car running while you squirt the car cleaner around the different vacuum hoses. When you spray a section of hose and hear the engine smooth out or the RPMs increase, that area is your problem. Keep squirting the area until you are able to locate the hose with the leak.

 

Do u have a check engine light on. If so what code a u getting when it is read?

 

possible vacuum leak and or throttle issue. do you hear a hissing sound under the hood when car is idle? is it the rpm or the car surging forward? could be trans issue.
crush