Hesitation when accelerating, only when first starting the c
 

Hi, I have a problem with acceleration (2004 S60 2.5T). When the car is first started, regardless of whether the engine is hot or cold, I get this stuttering hesitation.

I can get rid of it by accelerating at full throttle for a few seconds, eventually bringing back full power. It's strange, it almost feels like it unblocks something. The problem will then not come back until I switch off the engine and start it again. Even if I only switch off for a few seconds, it happens again every time.

My car has the plastic 'saddle' tank but does not have a PEM. Also does not have a pressure sensor on the fuel rail. I have replaced the fuel filter but the problem persists. Also cleaned ETM.

I am getting the dtc code P1234 (fuel pump driver module off line). As I said, I don't have a PEM on this car so I assume this is all handled by the ECM.

I would be very grateful if anyone has any ideas.

Thanks.

I had this and changed the TCV just a few days ago and all is good now.

If you havent looked, take off the VVT solenoids see if the green gasket filter is clogged.

the car cant breathe properly with VVT inactive and becomes sluggish