Hi there, please, I discovered that my Volvo xc90 is misbehaving lately, it hecitate and low in power while running, even at times refuse to accelerate while stepping on the pedal, rough idle.

I have changed the turbo charger lately but yesterday still experience the same issue, I just check the air flow sensor there is only 9volt supply to it not up to 12volt, does this have effect.

Regards

 

Did you scan for any stored fault codes? what happens if you disconnect the MAF? Have you inspected for any intake air leaks (a smoke test may be required)? Did you look at the MAF and intake tubing to see if there's any oil or film? Not sure why you decided to replace the turbo - was it leaking oil or coolant into the exhaust? Did you try cleaning the MAF with something like CRC MAF cleaner?

PS - plenty of vids on Youtube on how to test a MAF. Personally I'd start with the simple like checking for air leaks and see if the MAF / intake is clean and oil free.

 

The turbo charger was leaking oil,
Then after changing it we drove the car for almost 1hr suddenly the car started jerky as of it would stop, I removed the air flow sensor MAF connector and the vehicle operation became normal, the second day it started again.

I read the voltage supply to the MAF it only supply 9volt (not up to 12volt).

 

Given the turbo oil leak issue, I'd start by cleaning the MAF and throttle body on the assumption some oil may have found its way from the turbo to the MAF/throttle body - only takes a $6 can of MAF cleaner (don't use generic carb cleaner as its too harsh on the filament grid). Worst case is you'd be back to testing/shopping for a new MAF.

 

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THanks and what about the voltage I mentioned above to the MAF

 

not sure what pin you measured 9V on and whether its a direct voltage feed from a fuse. What year is your XC90? sounds like you may want to measure voltage at the fuse (in and out) and on the pin and any connections along the way (wiring diagram would help) and make sure the MAF's ground is clean.

https://www.matthewsvolvosite.com/fo...8f58&mode=view has some details which may help (this may be for older models... my 850T had the Motronic system which dates that version to the late 90s).

 

Model XC90Year 2005

 

https://qclt.com/html/volvo_ewd_us_e...x_3977202.html

See page 48.