Fuel rail pressure drops

[Alex Leet]

At idle it’s fluctuating betwen 4600-5000 kPa.
Fuel rail pressure drops instead of going up when turning off the engine (warmed), also sometimes (5-6k rpm) I get a pending P2293 Fuel pressure regulator 2 - performance problem, I also noticed bad fuel mileage. I made a video with the OBD-II info. https://youtube.com/shorts/5ehxZ3NWTyU?feature=share

 

[380bhpdaily]

Change the fuel return valve and retest.

 

[Alex Leet]

This?

 

[380bhpdaily]

Yes that’s it. Fit a new one and retest the car.

 

[Alex Leet]

Someone told me to try changing the fuel rail pressure sensor first and then that fuel return valve. I will change both.

 

[380bhpdaily]

Someone told me to try changing the fuel rail pressure sensor first and then that fuel return valve. I will change both.

Definitely do that first. Shame your not in the Uk as I have a good used one on a spare engine you could have borrowed to test if it helps fix it.

 

[Alex Leet]

I appreciate the initiative, mate. Tomorrow I’ll get the sensor and come back with update.

 

[Alex Leet]

Problem still not fixed after replacing the FRP sensor.

 

[380bhpdaily]

Problem still not fixed after replacing the FRP sensor.

Oh no sorry about that. Are you still getting the same code?

 

[Alex Leet]

Sorry. I think it fixed that code; today haven’t got it, I floored it in 3rd and 4th gear to 6k rpm without the pending P2293 code appearing. I’ll find out today after some more runs.
I said it didn’t fix the fuel pressure drop when engine is off. The pressure in rail was supposed to go up with warmed up engine; it’s dropping instead. I removed each spark plug to see if it’s wet and smells like gasoline, all 4 had no gasoline smell which tells me it’s not a leaking injector if I’m right, not getting any sort of smoke from exhaust, car accelerates smooth, no problems starting the engine when cold or warm. It’s just this pressure thing which is pissing me off, ‘cause I know somewhere is a problem since I noticed poor fuel mileage as well (or it’s just in my head) + in my friend’s Cupra the pressure is going up when turning the engine off.

 

[Alex Leet]

Hey, could fuel pressure drop through HPFP due to broken seals in the pump? I’m about to replace the HPFP. Do I need to remap again when replacing HPFP?