p0087 & Rough Idle

[Nichoxx]

Is that likely the cause then? Was hoping it wasn't that but no idea what else to try/test.

[mickeybo]

Your q5 engine code cglb 1 believe the first checks has to be fuel pressure control valve & fuel pressure sensor these 2 units are on the fuel rail. these 2 units are on the fuel rail both of these have a switched earth via ecu pin nos b45 & b6o & are inter connected IF this loses either of their earths theres no start at all

[Crasher]

Your q5 engine code cglb 1 believe the first checks has to be fuel pressure control valve & fuel pressure sensor these 2 units are on the fuel rail. these 2 units are on the fuel rail both of these have a switched earth via ecu pin nos b45 & b6o & are inter connected IF this loses either of their earths theres no start at all

They have been replaced

High pressure rail sensor and valve replaced. HPFP regulator replaced

[mickeybo]

I did post up if switched earths is gone in either 1 then you have a non starter A very very common fault

[Nichoxx]

Just to anyone in the future who stumbles upon this thread. One injector was found to be cracked and replaced however this did not solve the issue. The final outcome turned out to be something stuck inside the common rail - techs have no idea what is in there, or how it got in but swapping a new common rail in fixed it. HPFP was tested and found to be perfect.

[Crasher]

There was a TPI about replacing the rails, I will dig it out.

[Nichoxx]

Brilliant cheers

[Crasher]

What is the VIN?