Not sure if we got a death sentence on '07 V6 XC90... fuel pump, prop shaft, 2-3 cats + more?

[GreenMagicMan]

New fuel rail pressure sensor in (Bosch part). no change. Still runs horribly under load (up big Vermont hills).

Should I keep the parts cannon shooting and drive hour round trip to go get a fuel filter?
Running out of ideas of what's wrong with this car.

[pgill]

Reset the codes does the P0190 come back?

[chitownV]

Also, swap all 6 coils since half of them have already needed to be changed.

[pgill]

And disconnect the MAF (yes repeat that test!!!)

[GreenMagicMan]

I'll try re-setting codes.
About to install Hastings fuel filter.
will also try disconnecting MAF again - thanks for idea

[chitownV]

If that doesn't solve your problem, again, swap all 6 coils from the good 3.2.

[pgill]

GMM,

The Volvo 3.2 has Variable valve lift.

If your 3.2 is stuck at 3.6 mm lift then it would behave just like you described (starts and idles fine, but no power above 2000 RPMs)

When the engine switches to the large lift it open the intake valve 10.0 mm

Looking at the power graph for the 3.2 it looks like the small lift is limited to about 250 newton meters (184 ft * lbs) at about 2000 RPM

That's about 70 Horsepower at 2000 RPM


We can discuss what to swap next after you replace the fuel filter

[chitownV]

GMM,

The Volvo 3.2 has Variable valve lift.

If your 3.2 is stuck at 3.6 mm lift then it would behave just like you described (starts and idles fine, but no power above 2000 RPMs)

When the engine switches to the large lift it open the intake valve 10.0 mm

Looking at the power graph for the 3.2 it looks like the small lift is limited to about 250 newton meters (184 ft * lbs) at about 2000 RPM

That's about 70 Horsepower at 2000 RPM


We can discuss what to swap next after you replace the fuel filter

Would you suggest him to start focusing on cam switching before the ignition coils in which half of them needed to be changed?

Weak spark on-load from old coils (with an engine that has known coil issues) can also cause the low power and stuttering on-load. Broken spark plugs and torn coil boots can also do it. One reason I recommend to use the Volvo plugs before switching to aftermarket plugs when getting an engine to run right is so that aftermarket plugs don't cover-up the real issues of a poor running condition. If the plugs you suggested are indeed giving a better spark, then it could cover-up weak coil spark on-load. Swapping all 6 coils is free in his case and the good 6 coils from the other 3.2 are proven to work well. The next steps should keep in mind that the bad 3.2 engine replacement coils from the shop might not be good (short life), the spark plugs could have cracks in the ceramic, and that the problems could still be the fuel pump and/or the cats.

I'm not sure about jumping to the cam switching issue before known wear parts at 180k miles with no known maintenance history. That should come later and perhaps VIDA could help.

[pgill]

Coils first (its easy to swap)

Agreed

1. Swap coils (check wiring harness at top of engine is anything loose or disconnected?)
2. clear codes
3. test drive (Does MIL flash?)
4. Read codes
5. Check LTFT STFT

Report results here

[GreenMagicMan]

The fuel filter did nothing
There was a lot of sediment coming out of the filter AND out of the fuel line (coming from the tank I believe - it was the fuel hose facing the front of the car as connected to the filter).
Also tried disconnecting the MAF again, and no change.
Very interesting idea about the VVT - New territory for me - but thank you for the suggestion!!