[Enpethan]

Hello,

I have CEL "Drive moderately. Maximum drive train output not available"

However it will be turn off when restart to engine.

So I was trying to read OBD, it show high fuel pressure is too low and several cylinder is misfire.

My symptom are
- hard to start engine when in the morning
- no power when press gas pedal
- sometime engine is jerky

I had recall service fuel pump last year and recently i took to bmw dealer. They have reprograming HPFP. However i have same problem.

Anyone has same issue?

I have planing to replace spark plug and ignition coil first then will replace HPFP.

[Henry.Serem]

Should be your spark plugs, replace plugs, if it doesn't remove the misfire replace ignition coils & if that too doesn't work, change your injectors... in that order

[Bmw doubles]

If you can check your rail pressure that's how you can tell. At idle you should be around 700 psi and at load around 2k psi

[ziekxq]

Originally Posted by Bmw doubles

If you can check your rail pressure that's how you can tell. At idle you should be around 700 psi and at load around 2k psi

Hmm mine idle at 1000psi and at load 2600 psi.

[Bmw doubles]

Originally Posted by ziekxq

Hmm mine idle at 1000psi and at load 2600 psi.

What year is yours? Also yes with a tune 1000 at idle seems right and 2600 at load. Though once I get that Helix OD for the hpfp should be hitting 3k psi in the rail at the top end. There's some crazy videos on the gram rocking the helix overdrive smashing on fools.

This an n54 but I share the same pump as him.

[ziekxq]

I got 2011 so I got the old n54 style pump. I am def. going to do the Helix overdrive unit plus full e85 fuel lines and run straight e85 and I already did the lpfp stage 2 diy. But not till next summer as winter is approaching in Chicago.

Going to get intake valves walnut blast during Helix install.

Thinking of doing precision rw coils but I don't know... I need to do the custom intake too. Lol so much to do hehe.

[Bmw doubles]

Current fuel pressure at cold idle

[ziekxq]

Yeah mine is also 1000 - 1016 idle. I am excited to see your results... Maybe during winter I will build the custom intake and get precision rw coils. I just hope the auto can handle extra power lol.

[Bmw doubles]

Originally Posted by ziekxq

Yeah mine is also 1000 - 1016 idle. I am excited to see your results... Maybe during winter I will build the custom intake and get precision rw coils. I just hope the auto can handle extra power lol.

What's your wgdc at idle?

[ziekxq]

Originally Posted by Bmw doubles

What's your wgdc at idle?

Mine idles at 46-47... I wonder if that custom intake pipe help with the wgdc on your car.

[Bmw doubles]

Originally Posted by ziekxq

Mine idles at 46-47... I wonder if that custom intake pipe help with the wgdc on your car.

No mines alway been around that number. That makes me feel better about mine and yours you might need to replace your solenoid that controls the wastegate. Look into a little more before before pulling the trigger on that.

This guy is pretty legit and he has a video of him making 500whp with the Helix.

[ziekxq]

My mechanic recommend me to replace boost selenoid. Is that what you referring to?

[Bmw doubles]

Originally Posted by ziekxq

My mechanic recommend me to replace boost selenoid. Is that what you referring to?

Yes and i have a brand new OE one from FCP euro if you want to DM me.

[Enpethan]

I replaced spark plugs and ignition coils. However still vibrating and no power gas pedal sometimes. Should I need to replace HPFP?

[ezaircon4jc]

Originally Posted by Enpethan

I replaced spark plugs and ignition coils. However still vibrating and no power gas pedal sometimes. Should I need to replace HPFP?

IMHO you'll need a professional diagnosis; either dealer of competent indy.

[Enpethan]

Anyone know good dealer or indy in LA or OC area?
Thanks.

[Bmw doubles]

Originally Posted by Enpethan

Anyone know good dealer or indy in LA or OC area?
Thanks.

Yes hit up Rob at Speedlogic he handles a lot of mods and repairs.

[BimmerHausPerformance]

Originally Posted by Bmw doubles

No mines alway been around that number. That makes me feel better about mine and yours you might need to replace your solenoid that controls the wastegate. Look into a little more before before pulling the trigger on that.

This guy is pretty legit and he has a video of him making 500whp with the Helix.

Would WGDC be why sometimes when I'm under boost (not WOT but just normal acceleration) that sometimes I feel like my boost is being "gittery" or fluctuating as it builds?

That looks easy to replace at least.

[Bmw doubles]

Originally Posted by BrowBMW

Would WGDC be why sometimes when I'm under boost (not WOT but just normal acceleration) that sometimes I feel like my boost is being "gittery" or fluctuating as it builds?

That looks easy to replace at least.

It could be many things. First always turn traction all the way off of you want to be sure that nothing else's interferes with boost cut off. It could be
- bad DV
- wastegate not adjusted
- bad solenoid
- boost leak
- bad tune
- spark plugs not tapped down on a tune
- IATs too hot pulls timing
- coils going bad
- MAF sensor
- check engine light
- fueling

[Enpethan]

I replaced HPFP. I have solved problem.

[Romeo]

Are you replace aftermarket HPFP or you put original HPFP ?