2007 S60 Fuel Pressure Drop

tsnyder828 · Post by **tsnyder828** » 14 Jul 2018, 15:26

Hi All,

I just purchased a 2007 S60 which runs fine until the engine reaches operating temperature and then the engine starts to miss and will eventually stall. I have a Vida and it shows the following:

On start up the fuel pressure is about 400 kPa. Fuel pump at 55% utilization External pressure gauge attached to fuel rail is about 320 kPa. As soon as the coolant temperature reaches about 94 C the fuel pressure immediately starts to drop. When pressure reading from Vida reaches 120 kPa (external gauge about 0) the engine starts to miss. Fuel pump utilization has gone to 85%.

Any advice on which components are failing and how to test them? I suspect the fuel pressure sensor but don't understand why it would be sensitive to high engine temperature.

Thanks,
Tod

Post by **abscate** » 14 Jul 2018, 19:27

Search for the thread on troubleshooting the CEM and PEM modules forP2 fuel delivery

Fuel pressure sensor on fuel rail

Fuel pump relay integrated into Central Electrinic Module or CEM on P2

Pump electronics module, PEM on fuel tank or in trunk

Fuel pump

That’s the whole system.

Post by **oragex** » 15 Jul 2018, 04:08

Does the coolant needle or temp rise at a constant rate? As for the temperature, 94C at idle seems rather high, I get 87C at idle, and 91C-93C under hard acceleration.

380kpa is about right for a non turbo at idle

I don't see the relation between the coolant temp, unless there is an issue with the FSP getting warmed up from the engine black, and acting up. These cars have mainly two issues with the fuel delivery/pressure: the FPS and the PEM. On the other side, you don't know if the pump is the genuine one, so that may also be worth a check in case it was replaced with an inexpensive aftermarket part.

Just go maybe with used parts off Ebay as these can be expensive to buy new especially when not sure if the part is indeed faulty.

tsnyder828 · Post by **tsnyder828** » 21 Jul 2018, 14:38

Thanks for the feedback.

Can anyone explain how the plastic cup surrounding the fuel pump gets filled with fuel? When I have less than a 1/4 tank it almost seems like this cup is running out of fuel and the fuel pressure starts to drop.

Also, if there is more fuel on the left side of tank (18 liters) versus the right side (6 liters) how fast should the two sides equalize when idling.