New V70 II T5 owner - introduction and general advice Topic is solved

[matthew1]

I'd change the fuel filter.

[lrock]

just recently mine was in limp mode, removed throttle body, cleaned it, replaced with new gasket, out of limp mode. Though my throttle (the difference between the two sensors is supposed to be<15 degrees or something, mine was 78 according to vida.) module still needs replaced, this at least got it working a lot better. Also do a glove test to see if you need to clean the pcv breather system.

[hiroku]

just recently mine was in limp mode, removed throttle body, cleaned it, replaced with new gasket, out of limp mode. Though my throttle (the difference between the two sensors is supposed to be<15 degrees or something, mine was 78 according to vida.) module still needs replaced, this at least got it working a lot better. Also do a glove test to see if you need to clean the pcv breather system.

Did the PCV test yesterday, the engine really tried to gobble up the glove, so quite pleased with the result. Haven't tested under boost yet, but it's very promising.

ETM module was replaced by the previous owner at the Volvo dealer. It's the only receipt I have of work done on this car!

[hiroku]

I was looking at yesterday's logs more closely, and found something interesting.

This plot is the calculated boost on top, and short term fuel trims on the bottom. Both values are shown over time, during a test drive.



Seems to be a correlation between positive relative pressure (boost) and positive fuel trims. The way I remember it, positive trims are the ECU opening the injectors for longer to try and put more fuel in the engine, trying to compensate for a lean mixture. Means the engine isn't getting enough fuel.

Could mean a lot of things, but this is consistent with the theory of low fuel pressure that we have been discussing.

I'll order a new fuel filter and clean the injectors. Should I also order a new fuel pump?

If you'll remember, this car fails to hold pressure on the rail while it's shut off. I parked for about 10 minutes to get takeaway, and when I came back, it cranked for around 5, 6 seconds until it started. Previous owner claims his mechanic said it's some failed no-return valve. Wondering if the issues could be related.

The parts diagrams don't seem to show any return valve or fuel pressure regulator, so I'm assuming it's all part of the fuel pump assembly on this returnless system.

Thanks!

[jonesg]

yeh I would order the pump, you have enough data to call it.
Mine holds pressure overnite, I don't know precisely how much but theres pressure at the rail.

If you have the elm 327 you can monitor vacuum and boost whilst driving.

[lrock]

yeh I would order the pump, you have enough data to call it.
Mine holds pressure overnite, I don't know precisely how much but theres pressure at the rail.

mine still had pressure after sitting undriven for 8 years