1997 v70 T5 Stutter at WOT on T5

Post by **hausmeister** » 11 Mar 2021, 02:54

(I actually meant a pressure tester for the intake, 2 plugs, one with a manometer where you can connect a compressor and test it for leaks)

For fuel pressure I'd check idle and blip throttle. I would not want a fuel hose in the cabin, maybe tape the gauge to the windscreen securely if you want to test it during a drive? Not sure if you really need to do that test, I would be very careful either way.
ChrisFix has a video on testing fuel pressure, maybe that is helpful:

Post by **Fiodor** » 15 Mar 2021, 11:35

Okay, tested the fuel pressure today, seems fine to me.
Key on position 2

At idle

Blipping the throttle while stationary

Post by **Sveedy** » 15 Mar 2021, 18:43

I believe at idle you should be at 43psi. So you might be on to a problem.

Post by **misha** » 16 Mar 2021, 02:29

Sveedy wrote: 15 Mar 2021, 18:43 I believe at idle you should be at 43psi. So you might be on to a problem.

No,Sveedy...it have vacuum controlled FPR at fuel rail.
M4.4 with FPR at fuel filter have steady 43 psi all the time.
With FPR at fuel rail,fuel pressure changes at idle and at WOT...but on 1st prime it should be at 43 psi and at WOT.
At idle it should be around 35 psi because the vacuum controls it.

Post by **abscate** » 16 Mar 2021, 05:05

Added year model to title

Post by **Sveedy** » 16 Mar 2021, 07:28

Thanks for clarifying Misha !

Post by **Fiodor** » 16 Mar 2021, 08:37

Indeed, I have my FPR on the rail !

Post by **Sveedy** » 16 Mar 2021, 08:48

So quick question: If I'm set up with M4.4 but have a FPR on the rail, what should my pressure be ? 35psi at idle ?
If so then I'm getting a little too much pressure myself.

Now back to Fiodor's problem...

Post by **misha** » 16 Mar 2021, 11:40

Sveedy wrote: 16 Mar 2021, 08:48 So quick question: If I'm set up with M4.4 but have a FPR on the rail, what should my pressure be ? 35psi at idle ?
If so then I'm getting a little too much pressure myself.

Now back to Fiodor's problem...

Yes...if FPR is stock.
With factory setup,M4.4 cars have constant 43.5psi fuel pressure no matter if engine is idling or at WOT.