[el1818]

I have been having hard time rectifying the problem causing low boost error.I have the procede v5 and the fuel gauge as boost gauge. The most it read 9-11 psi wben i set it to 15 psi. Not only it doesn't run full boost but as well as fluactuating around 9-11 psi @wot and a very obvious hestitation when the rpm rises.

I initially thought it is tune related and took the procede off. The results were the same. It happens to stock too.

That's no leak at dv, intercooler piping, check all vacuum hoses and are all well. My guess were the wastegate actuactors and had them both changed but still no luck.

And my mechanic suggested that it might be the hpfp causing the problem.
I am sceptical to believe him since its boost issue not fuel related. The cel code (can't remember the number) said low boost error.

Can someone please direct me to where i should look into further???

[Tzu]

You may have better luck in the Turbo section.

What mods do you have? What octane gas do you run?

[wesborl898]

Originally Posted by el1818

I have been having hard time rectifying the problem causing low boost error.I have the procede v5 and the fuel gauge as boost gauge. The most it read 9-11 psi wben i set it to 15 psi. Not only it doesn't run full boost but as well as fluactuating around 9-11 psi @wot and a very obvious hestitation when the rpm rises.

I initially thought it is tune related and took the procede off. The results were the same. It happens to stock too.

That's no leak at dv, intercooler piping, check all vacuum hoses and are all well. My guess were the wastegate actuactors and had them both changed but still no luck.

And my mechanic suggested that it might be the hpfp causing the problem.
I am sceptical to believe him since its boost issue not fuel related. The cel code (can't remember the number) said low boost error.

Can someone please direct me to where i should look into further???

Check your intercooler piping again. If there is obvious hesitation when WOT, there is definitely boost leak. I doubt its the vacuum lines because it sounds like a lot of boost loss. Pretty sure it's intercooler related, especially if you have a aftermarket intercooler.

As far as HPFP being the issue, I doubt it because you'll have longer cranks and have more codes with fuel related.

Do you have warranty? If so, make sure its back to stock and take it in!
Warren

[el1818]

I am out of warranty.Taking it to bmw dealer will be my very last choice.

It drives fine during light throttle,no hesitation or whatsoever but real hestitation only when at wot. The rpm climbs, pauses,climbs, pauses and at the same time you can see the boost gauge swing 9 psi, 6 psi, 10psi, 7psi,( constantly swinging in between 6-10 psi).


yup, i reckon it would be turbo related issue and nothing to do with the hpfp.Shall recheck the intercooler piping.

Hopefully, will find the culprit to the problem soon.