I have a 2012 Cooper S Manual with 84,000 miles, and am having random issues with my cold starts. Sometimes the car sputters and misfires, the other day it stalled. Other days it starts up just fine with no error codes or Check engine lights. Ideas?

 

You need to have the codes pulled, as well as have someone with a quality scan tool watch parameters as you do a cold start. If the fuel pressure numbers are low or struggle to maintain requested, you'll need a HPFP, but there are other problems that can cause a hard/no start in the cold.

 

just for reference, my HPFP reads ~700psi at idle on cold start using OBDII scan tool.. it fluctuates a small amount at idle..and should roll up to +1400 when you tip into the throttle. Ive logged peak values on mine ~2k psi ...

pick up a cheap OBDII scanner and plug it .. see what you got!

**Also wanted to mention; Ive seen variance on Boost and AFR readings before from one OBDII scanner to another.. but fuel rail pressure, CAT temp, engine timing and IAT are all identical values when I compare.

 

hey I have an odb reader and plugged it in and recorded the fuel rail pressure psi ( ) this was a warm start. Is it supposed to be that high?

 

I had a Random Misfire in Cylinder 1 and a Random Misfire in Cylinder three the other day. Talked to a couple of indy shops around me and they basically thought it was the high pressure fuel pump. But my car isn’t not starting-just sputtering on cold starts. I have an appt. at mini of alexandria which is three hours away from me-I asked them just to check the HPFP and if it’s not that not to do anything bc I don’t want to be screwed over.

 

2000inhg is roughly 980psi..so it is a little high. But not too bad, the injector heads could be fouled up a bit and choking output..

**update:
39f ambient this morning..
~720psi initial..
after about 10s running, it raise to ~930psi
it sat between 910 and 1070psi on idle until the coolant temps were over ~120f.. then fuel pressure returned to ~750psi. Once fully warm it idles with fuel pressure ~700psi on the nose.

 

Got the P15DF code (high pressure fuel pump) and am going to have to go to the dealer (two hours away) :/

Is it safe to drive there?

 

You should be fine driving, it's not often the pump is too tired to keep you moving 60 MPH, I've only seen a handful of cars that didn't want to move under their own power even in limp mode.