Long crank issue - fuel pressure question

[Cabriolet]

srsly look at replacing this.

try another crank position sensor. i've seen this happen is the KPS is going bad.

your fuel pump will not come on if the DME is not detecting that it is cranking.

[Hoffbrohaus]

srsly look at replacing this.


your fuel pump will not come on if the DME is not detecting that it is cranking.

srsly look at replacing this.


your fuel pump will not come on if the DME is not detecting that it is cranking.

It is within spec, I tested the resistance to be 577, bentley says "If the resistance is not approximately 540 ± 54 ohms, the sensor is faulty and should be replaced ."

yes the check valve is in the pump assembly to control pressure on feed side and the FPR stops flow to hold pressure on the return side

to test which is allowing bleed down pinch the return line after the FPR after cycling pump and if pressure still drops pump check valve is bad ,if it doesnt bleed down until you release pinched hose regulator is bad (it has a spring loaded seat that sets hold pressure inside it )

Ok this is wierd. I jumpered the relay, fuel pressure = 46 psi and Bentley says 43.5+-.9. Pinched the line after the FPR and pressure rose to 80 with pump on, with pump off it held at 40psi. I un-pinched it and it still held at 40psi. ran pump again without pinching and it held at 40psi, waited longer, pump on then off again, dropped to 0.

Trying a different FPR next.

[Hoffbrohaus]

Just an update, I put in the new FPR part # 0280160249. and noticed a small change. At least now it holds pressure a little longer but still bleeds off slowly. The odd thing was the FPR I had on previously was part # 0280160226. Looked it up and it's a 3 bar FPR so not sure what the difference is.

All this to say my rail is still not holding pressure, I have problems with long crank (worse when cold) and my idle is lumpy like a big cam.

[968Reckless]

Just an update, I put in the new FPR part # 0280160249. and noticed a small change. At least now it holds pressure a little longer but still bleeds off slowly. The odd thing was the FPR I had on previously was part # 0280160226. Looked it up and it's a 3 bar FPR so not sure what the difference is.

All this to say my rail is still not holding pressure, I have problems with long crank (worse when cold) and my idle is lumpy like a big cam.

Any news on this?

[Hoffbrohaus]

Any news on this?

Nothing new. I checked the resistance again on my coolant temp sensor and it was fine. I also double checked the resistance on the AFM as the door opens, it was fine.

I'm kinda stuck now, not sure what to check next.

[Hoffbrohaus]

I was buttoning up my glove box trim pieces this morning and noticed the wiring loom into the ECU connector had the tape unwrapped. I thought it may have happened due to time but also noticed some wires spliced together. So I wondered did the PO rewire something in the ECU?

I thought I remembered reading something about rewiring an ecu with an M30 AFM or 19# injectors, or something else. Anyone know?