Fuel system acting up in stange ways

henrijeret · Post by **henrijeret** » 01 Jul 2020, 01:14

It would be interesting to figure this out. Lost my job and with no money - need to make sense of it without a huge bill from a workshop.

The car is a 2002 XC70 D5 120kw (power has been modified to be higher with a computer)

My problem:
If the tank is full then the car runs fine. Only if I need to accelerate hard, then a significant delay is present (I have owned a volvo with the same motor and everything, the difference is there clearly). Also have seen a report of low fuel pressure when checking codes a couple of times.

If I drive for ~300km, then the car occasionally shuts down. After sitting for a couple of minutes, then it starts up and I can drive to a fuel station (one time even 70km away).

Recently climbed a steep hill on the highway and the car stopped when I reached the top. After again waiting for a moment - it started right up again and I was able to drive home just fine.

Starting the car after these shut downs is like the fuel lines were empty.

Some repairs done recently
New motor (used) and pump (new new) installed 2 years ago.

I have been driving like this refueling after every 200km for a while now. But the hill climb and engine shut down motivated to get to the bottom of this problem once and for all.

I cannot see much wrong visually. There are some small specs of some kind of dirt here and there then I took the fuel out. Could there be a blockage?

It seems like everything runs quite fine as long as the fuel level is above the pump housing edge and the car is struggling to get fuel from the bottom of the tank from the other side.

Post by **jonesg** » 01 Jul 2020, 03:04

Have you checked fuel pressure at the rail, you can use a cheapo tire pressure guage if it has a schraeder valve, discard the pressure guage afterward.

Post by **abscate** » 01 Jul 2020, 03:57

I think this a Diesel engine which we do not get here in the States.

Our Europe members know more about these engines

Svieks!

Post by **oragex** » 01 Jul 2020, 07:06

I would also investigate the throttle body. May try to open it, see how it looks inside for any wear on contacts, maybe clean it
For D5 specific questions, try this forum https://www.volvoforums.org.uk/forumdisplay.php?f=19