2004 XC90 lag + lurching during highway acceleration

brunocerous · Post by **brunocerous** » 17 Dec 2021, 09:51

Greetings!

On a recent trip, I noticed our 2004 XC90 AWD would act oddly when trying to pass on the highway or accelerate up a long hill.

Upon accelerating, the engine would first lag and then rhythmically lurch (lurch/lag/lurch/lag/etc.). If I ease off the accelerator, it would resume running normally.

I’ve been running premium fuel. Could it be an air intake issue or perhaps a camshaft sensor? Any help, of course, would be greatly appreciated!

Bruno

Capndirk · Post by **Capndirk** » 27 Dec 2021, 10:16

A proper VIDA scan might be the best way to find the issue. My wife's '13 S60 had similar symptoms, and no DIM faults noted. I ran VIDA on it and the DTC code was for the fuel pressure sensor. Changed that out and it was healed. I know it's a different engine, YM, and later tech, but the point is the fault was pinpointed and fixed the first time. If you don't have VIDA, maybe an OBDII reader can get you close. There are also other owners in your area with VIDA that may help. I saw one poster on another forum volunteer his VIDA-Dice services in New Jersey to another owner.

Post by **abscate** » 27 Dec 2021, 11:11

brunocerous wrote: ↑17 Dec 2021, 09:51 Greetings!

On a recent trip, I noticed our 2004 XC90 AWD would act oddly when trying to pass on the highway or accelerate up a long hill.

Upon accelerating, the engine would first lag and then rhythmically lurch (lurch/lag/lurch/lag/etc.). If I ease off the accelerator, it would resume running normally.

I’ve been running premium fuel. Could it be an air intake issue or perhaps a camshaft sensor? Any help, of course, would be greatly appreciated!

Bruno

Missed this one, Bruno

It does sound more like an FPS or PEM problem, which often don't code. Fuel pressure monitoring might be the only way to catch it. Cam and crank sensors will almost always code. Misfires will code once they happen 'enough' but the misfire count in VIDA never lies. Well, almost never.

brunocerous · Post by **brunocerous** » 07 Jan 2022, 07:17

Thank you both. I do like the idea of knowing for sure, so now I have a snowy day to attempt getting my VIDA setup (actually my brother’s) to work!

chitownV · Post by **chitownV** » 08 Jan 2022, 17:01

brunocerous wrote: ↑17 Dec 2021, 09:51 Greetings!

On a recent trip, I noticed our 2004 XC90 AWD would act oddly when trying to pass on the highway or accelerate up a long hill.

Upon accelerating, the engine would first lag and then rhythmically lurch (lurch/lag/lurch/lag/etc.). If I ease off the accelerator, it would resume running normally.

I’ve been running premium fuel. Could it be an air intake issue or perhaps a camshaft sensor? Any help, of course, would be greatly appreciated!

Bruno

Had to instruct someone 800 miles away to do this to a 2.5t XC90 recently and sent them to Autozone. The typical Autozone generic OBDII scanner will scan the fuel pressure sensor since it is related to the emissions. The FPS should throw a dash light or message. Scanning for a saved code, as mentioned, should certainly show if this is the exact issue.

Another place to look at, which might not throw a code, is the turbo control valve (TCV), aka boost pressure solenoid. This cheap part regulates the boost (via wastegate) and can have issues with wear and age such as sticking, not completely opening, etc. Thus, you might not be getting enough boost upon load. Sometimes lower gears can mask this as the engine can rev faster, but load issues are clearer on the highway as you have noted.