[ZeBoost]

Hello All,

Like the title states, I've got a 535i with a long crank and random misfires at idle.

Active codes are misc K-CAN/CAN errors, which I believe are due to to a shorted iDrive controller and a 119202 FUEL LOW PRESSURE SENSOR, ELECTRICAL: SHORT CIRCUIT TO GROUND. The latter is odd because the car doesn't have a LP fuel sensor. I'm also showing two shadow codes related to fuel; 11A401: HIGH FUEL PRESSURE WHEN INJECTION IS RELEASED: PRESSURE TOO LOW and 11B401: HIGH PRESSURE DURING OR AFTER THE INJECTION IS RELEASED (2ND ENVIRONMENTAL CONDITION SENTENCE AFTER TIME DELAY): PRESSURE TOO LOW.

I've logged HPFP at start, idle and med. load and those appear to be good. Via the rail pressure sensor, I can tell that the car has adequate pressure before cranking indicating the LPFP/check valve appear to be good as well.

The car has new BMW Bosch plugs and coils.

One final note, the misfires at idle are apx 80% better when in sport or sport +. The car pulls hard and misfires aren't apparent anywhere else in the rev range. Hoping someone with some knowledge of these codes can provide some insight. I do plan on tracking down ISTA and a laptop to do some additional diagnostics but I just recently got the car up and running (alternator replacement).

Thanks!

[Trainwreck914]

I'm having long crank issues. At first I thought it was my battery. Replaced it. Still exists. Did walnut blasting. Still exists. Car ran much better after blasting. Now I'm getting misfire "feel". Hesitation and stumble at idle. No codes. Sometimes the stumble can be violent. Popped the hood and it sounds like an injector isn't working properly. Car is at 137k miles. I'll be replacing the injectors soon. Most likely they are the culprit

[ZeBoost]

Interesting, what I’m feeling in my car, as far as the misfires at idle, do seem to be a fuel issue. I’m trying to get my hands on diagnostic software to run fuel system tests. I’m thinking my issue is the hpfp but I’d like to get some confirmation before dropping $700 on the pump. Are you getting misfires at load or just idle? Keep me posted on what you end up doing and if it cures your issue.

[Bmwfan55]

100% HPFP. Had the same issues and replacing the unit fixed it

[ZeBoost]

I'm leaning that way, by chance have you seen that 119202 code for a LP fuel sensor short on a car that doesn't have a LP sensor? In the pinout diagram of the ECU there is a signal wire for a LP fuel sensor signal wire associated with the continental HPFP. I'm starting to wonder if there is someway they HPFP provides a LP signal somehow.

Did you experience the Sport mode smoothing out the idle as well?

[Bmwfan55]

Originally Posted by ZeBoost

I'm leaning that way, by chance have you seen that 119202 code for a LP fuel sensor short on a car that doesn't have a LP sensor? In the pinout diagram of the ECU there is a signal wire for a LP fuel sensor signal wire associated with the continental HPFP. I'm starting to wonder if there is someway they HPFP provides a LP signal somehow.

Did you experience the Sport mode smoothing out the idle as well?

Didn't have any codes. Just symptoms. I'm sure it's the HPFP. Try a remanufactured part from ecs tuning. They use updated parts on a used core, and you get around $60 if you send your old pump back to them. Will last longer than a brand new from the dealership.

[ZeBoost]

Thanks for the input, like I said, I am leaning that way. I may just bite the bullet and grab one. ECS has a kit that includes the misc gaskets and HP fuel sensor.

[Bmwfan55]

Originally Posted by ZeBoost

Thanks for the input, like I said, I am leaning that way. I may just bite the bullet and grab one. ECS has a kit that includes the misc gaskets and HP fuel sensor.

Do it. Once your bmw works the way it should, the satisfaction itself is worth it

[ZeBoost]

Hello All,

Just to keep those who've responded and those who may be curious about the vehicle up to date, I was able to run diagnostics through INPA and the HPFP appears to be the issue. Fuel pressure at crank takes too long to build and at idle it fluctuates enough to potentially be the cause of my misfires. When the car is at higher RPMs the pump is able to keep up, which is why I don't feel the misfires anywhere but idle. This more than likely points to seal degradation inside of the HPFP. I've ordered a new HPFP, misc gaskets and a new HP sensor from ECS as part of a kit they offer. I should have the parts installed in the next 1-2 weeks and will report back then.

[mashpotato]

Did u have your lpfp replaced? There was a recall for 2011?
check engine grounding as well (hook up a battery cable to chassis and the engine like near the oil filter). See if things improve

[Trainwreck914]

I haven't had a chance to really look into mine yet. Didn't even think to check ista. Maybe you're on to something. I check ista and probably go that route instead of doing the injectors. I did my lpfp over the summer. And it's too cold to work on the car now. I did manage to replace my rear driver side strut and spring yesterday as it was near 40*. My spring broke FYI. Apparently the f10 is known for that also.

[ZeBoost]

I did check and there are no open recalls on the car. LPFP looked good via INPA testing. The engine grounding one is something I will add to the list of things to check. Thanks for the heads up on that. Based on what I saw in INPA, the HPFP is working but it's def. tired, so I'm going to replace and rule that out. The head scratcher is that there is a shadow code for a shorted LP fuel sensor and the car doesn't have that sensor, at least, not where it's supposed to be (HPFP supply line).

For the grounds, is there a specific one I should check? I know there is one on the driver side but I plan on going through them thoroughly. When I bought the car it needed an alternator, after I replaced it I did a few tests with a multimeter (at the alt, at the battery, charging posts) to make sure voltage was traveling with minimal resistance and that looked good.

[ZeBoost]

Originally Posted by Trainwreck914

I haven't had a chance to really look into mine yet. Didn't even think to check ista. Maybe you're on to something. I check ista and probably go that route instead of doing the injectors. I did my lpfp over the summer. And it's too cold to work on the car now. I did manage to replace my rear driver side strut and spring yesterday as it was near 40*. My spring broke FYI. Apparently the f10 is known for that also.

From what I've been told, injectors will typically throw codes related to fuel mixture (lean, rich) or an ignition shut down. You can also check your short and long fuel trims to see if there are extreme adjustments there, which could help identify an injector issue and even narrow it down to a bank.

Based on the diagnostics data, I went the HPFP route as I'm not getting any mixture or ignition shut down codes. As I mentioned it my previous update post, once I get the pump kit I'll report back.

[ZeBoost]

Originally Posted by mashpotato

Did u have your lpfp replaced? There was a recall for 2011?
check engine grounding as well (hook up a battery cable to chassis and the engine like near the oil filter). See if things improve

I just saw your edit, that's a great idea. I'm going to try that this afternoon.

[ZeBoost]

A quick update for those interested and those who may stumble on this thread, I received the HPFP kit from ECS yesterday and will be installing this weekend. Once it's in, I'll report back.

[Bmwfan55]

Originally Posted by ZeBoost

A quick update for those interested and those who may stumble on this thread, I received the HPFP kit from ECS yesterday and will be installing this weekend. Once it's in, I'll report back.

Before I did my hpfp the only issue I had was long crank at cold start. Otherwise the car ran normal, never threw any codes nor acted up. I lived with it for 4 years till I decided to it. it now starts right up when cold. I too bought the unit at ecs tuning. Reman with 1 year warranty. Make sure you send them your old one, they knock $70 off the price.

[ZeBoost]

An update for anyone who may stumble on this thread: after swapping out the HPFP and HP fuel sensor, the long crank is now resolved. The car fires up in about half a second every time; cold, hot, sitting for a while, turn off and back on, etc. It doesn't matter, the car fires right up every single time. But the intermittent miss at idle is still there. I used new gaskets and was careful putting everything back together again. The carbon build up at the valves didn't look too bad. I'm now suspecting I have a vacuum leak as the car runs strong everywhere in the rev range, doesn't smell rich or foul plugs (no CEL or shadow codes related to misfire, fuel, ignition, etc.). The next step will be a smoke test to see if I can find a leak.