Hi,

This morning during a cold start-up, got limp mode and p0087 code. Idle was very unstable.

Researching on the forum, I verified the gas cap, seems to be ok.

Erased the code with Torque app, and runned 30 min around with high revs and didn`t get code again.

Torque shows Fuel Rail pressure on idle (700-800rpm) around 1170-1200psi

R56 10/11 with N18 engie.

Thanks

 

With ignition switched on, 63,8 psi

 

With ignition switched on and cold engine, got 59 psi. Should it be 70 psi? Is it a premature symptom of failure in my HPFP?

2 days past of the problem and no problems on cold start again.

 

It's most likely a failing HPFP, but next time it happens don't help it live, let it fight for it's life and hopefully give you more codes, if you get a P2280 that is undeniable evidence of a dead pump, but the P0087 isn't far behind that.

 

Keep getting intermittent p0087 code, what I'm realizing when the fuel level is too low it's when it's happening.

 

Been dealing with a lot of HPFP drama myself. Had the cold start behavior this AM. I also made a similar observation to yours, about a correlation with fuel level, today with my current HPFP (which I know for a fact is failing). Interestingly, post-fillup and with the engine 100% warmed up (had been driving for hours), clearing the code didn't help the HPFP figure itself out again. Subsequent drive (car still very much warm) it threw the P0087 again and monitoring with an app+OBD adapter showed that rail pressure was down to sub-100.

To get it back I had to stop the car, start it, and then rev the engine to get it to pop into the 600-1000+ range (and gently let it down so it didn't crash). Note that it took 2 attempts to get that to work, and the only reason I knew the "trick" (whatever kind of trick it is) is because I figured that bit of tactical out with my original HPFP.

My current HPFP is leaking oil from the looks of it (not engine oil -- there is oil inside the unit, part of how it does its magic), so there is no question I have an issue. This HPFP is an aftermarket replacement for the original HPFP, which did not have a leak but exhibited identical failure behaviors.

Hope this provides you with some context. There is more to my situation, I've puzzled out some interaction with spark plugs and O2 sensors needing replacement, but even in doing those the bottom line is that a failing HPFP is a failing HPFP. Other random things will annoy it more, but if it's on the way out it's on the way out.

PS I replaced my LPFP before replacing the HPFP. Replacement HPFP is doing the same stuff as the original one so the LPFP clearly isn't at issue.

EDIT: A fellow forum member suggested replacement of the fuel pressure sensor (which is apparently not sold as a separate item in the US, or at least I can't find it that way). Going to go ahead and replace mine -- the cold start issue has appeared across more than one HPFP so maybe that's the key. Will come back and give an update but it may be a handful of weeks.

 

Have you found a cure for this yet?

i have exactly the same issues as you. However, I have no startup issues at all.

car will come to life, seemingly fine and then I will get either increased emissions, or I’ll get reduced power.

Diagnostics freeze at point of code states that psi is at 78. However, once clearing the fault, the live data sits at 700 psi.

Sensor?

When the fault is cleared I can achieve full power with no problems.

 

Just played around with the reader and my car again.

On startup I got a P0087 code. Fuel Rail Pressure at 75.2psi.
Cleared the code and went for a drive.
Turned car off, turned car on. Fuel Rail Pressure again at ~75psi.
On hard acceleration I got multiple misfires and the codes P0302, P0304 and P0300.
Turned car off, turned car on. EML light on codes stay the same.
Checked Fuel Rail Pressure - 700psi + at all times, often gusting over 1000psi.
Car accelerates hard, sometimes stutters at peak power range.

What the hell is going on? Sensor or HPFP? Guess I’m going to have to replace both.

 

The sub-100 PSI, when it holds, is almost certainly the computer putting your car in limp mode. You can confirm by trying to rev above 4000 RPM — even in park, it will go no higher, but won’t buck or sputter or other behavioral sign of trouble. It will simply top out without obvious explanation (other than knowing what limp mode does).

Funky behavior when you’re in the 600+ range is a traditional HPFP fail symptom, but the rub is that if your fuel pressure sensor is misbehaving, you have no way to eliminate either as the cause. It’s a chicken-egg troubleshooting situation that I have seen no way to sort other than throwing parts at it or waiting until something fully dies.

I have my Mini in drydock until next week. I have been working on HPFP rebuild experiments, documented in another thread, but I got a really significant and unexpected sign today that my fuel pressure sensor may be on its way out. No way to be sure so just doing the replacement. But won’t be able to touch it until next week.