Hi everyone!

I have a 2005 Fiesta 1.4 tdci. It has been jerking during acceleration for years, but most recently, the situation has been getting worse, I also received P0089 and P0002 errors. While driving, until the fuel pressure reaches about 400 bar, there is nothing wrong. From about 500bar it starts to jump up and down +/- 100 bar. There is nothing wrong when stationary, even when I rev it, idling is fine, the error only occurs at high pressure, under load. The pump itself could be bad, or one of the 2 regulators on the pump? Maybe the sensor at the end of the rail pipe? Or it could be a wiring error again, because a few weeks ago there was an injector error due to a lack of wire contact. But then why does it only occur above a certain pressure? I just removed the high-pressure pump, but the renovation is expensive, the dismantled part is risky, and everything is closed this time of year, and I need the car next week.

I hope someone can help me.

Thank you in advance,

Tamas

My standard answer: when was the fuel filter last changed? Doesn't matter what you answer, anything fuel related, just change it.

Beyond that.
https://www.engine-codes.com/p0089.html

https://www.dtcdecode.com/Ford/P0089

https://www.engine-codes.com/p0002.html

You have obviously got access to fuel rail pressure but how does this compare to demanded?
Any Ford specific codes other than the above (Forscan?)
If actual varies whilst demanded stays the same then it's back to tank pump, filter or regulator (works on PWM so need to check the solenoid on the pump and all wiring and control waveforms/inputs/rail pressure sensor?)