[E92 420]

First off, hi all it's my first post on here.

I have a 2006 335i auto.

I bought the car a year ago, it was completely stock. Within a month I took it down to evolve and had it mapped it made 379 bhp and 415 lbs/ft. For the first day the car ran well and felt fast on the second day the car felt sluggish and not like it was. Called evolve and explained the situation they told me to bring the car back and they would have a look and change some coding in the ecu.
Got there at 9am and didn't leave till 5pm. In that time they tried to load various different maps and ech time the car would just crank and not start it would only start and run with the stock bin loaded! In the end they refunded my money and sent me on my way. They said they had never experienced this before and cannot help me. To say I was gutted was an understatement.

Since then I have fitted a jb4 g5 ISO and a dci. Again car ran great for about a month this time then back to its old tricks and down on power, shortly after that It started getting bad boost oscillations but only in 3rd and 4th gear when going WOT from 3000 rpm upwards the car literally feels like it kangaroos! If I go WOT from 2000rpm then I get no boost oscillations but it still feels down on power.
So then I put vrsf DP on and and active autowerk fmic and a forge cp with forge 50mm BOV then loaded a custom backend flash. None of that helped the issues. So I replaced the turbos all vac lines put RB PCV valve in and replaced both boost solenoids. Still the same issues.

I am literally at my wits end with this thing it's turning my hair grey!

Has anyone experienced these issues?

Any help would be appreciated

[Sparky68]

Only thing you have not mentioned is the Vacuum canisters . I had loads of boost issues and replaced nearly everything bar the turbo's
hunting it down. Turned out it was a faulty O2 sensor the whole time.

[Sparky68]

Have you pulled the codes from it ?

[E92 420]

Originally Posted by Sparky68

Have you pulled the codes from it ?

Thank for the reply

I replaced 2 O2 sensors when I installed the DPs about 6 months ago because they were throwing codes. Not to say they arnt causing issues without throwing codes now tho.

I have pulled the codes and there were a couple of shadow codes stored. I'm away at the moment so can't get to the list that I wrote down. But will post them up when I'm back.

I have had the vacuum canisters off and they looked ok no visible splits/cracks but may still be worth changing just to elliminate them.

I have my fuel gauge set as the boost gauge through the jb4 canbus system and when it doesn't oscillate the boost ramps up quickly and holds well at what I have it set at

[Sparky68]

Do you get issues when running the standard map , you should log a few runs and send them to Terry burgertuning he is very very helpful.

[E92 420]

Originally Posted by Sparky68

Do you get issues when running the standard map , you should log a few runs and send them to Terry burgertuning he is very very helpful.

Yes even before the backend flash. It seems to be when the car goes above 14 psi the oscillations start. Ill get a load of logs done n post them up when I get back and send a few to terry

[E92 420]

Originally Posted by Sparky68

Have you pulled the codes from it ?

Ok here's the codes

I'm using INPA software and a K+DCAN cable I can delete these codes and they will come straight back. Can ignor the DP codes

2fa3 coding missing
29f4 catalytic converter conversion
29f5 catalytic converter conversion
2fdb ??? Shadow code
30ff under boost
2fca ??? Shadow code
2fda ??? Shadow code

As for the 30ff iv checked tighten'd and rechecked all intercooler pipe work all is fine charge pipe is fine with no leaks BOV no leaks both compressor outlets on each turbo fine no leaks. All vac lines replaced! Both boost solenoids and turbos replaced about months ago.

Weathers crap so can't log right now

[nicktyler]

Could it be an fueling/ignition problem? I had similar symptoms that were down to worn plugs and a dodgy injector. Also maybe the HPFP?

I guess these issues would probably cause misfires and throw codes but you seem to have mentioned everything else.

[windymissile]

Take the JB4 out and see if the problem is still there.
Physically remove it. Don't just map 0 it.
I did this and my under boost went away. Turned out to be a simple setting in the JB4.
Did you say you have new turbos?

WM

[E92 420]

Originally Posted by nicktyler

Could it be an fueling/ignition problem? I had similar symptoms that were down to worn plugs and a dodgy injector. Also maybe the HPFP?

I guess these issues would probably cause misfires and throw codes but you seem to have mentioned everything else.

I replaced all 6 injectors and coded them in 2 months ago and the plugs are ngk 5992 all gapped correctly and have covered around 3000 miles. From the last logs I done around a month ago the HPFP and LPFP look strong.

[nicktyler]

I can imagine why you are going grey over this as you seem to have covered every possibility.

The only other thing I can think of is sticky waste gates or actuators. Are the symptoms consistent and easily replicated or a bit random?

[E92 420]

Originally Posted by windymissile

Take the JB4 out and see if the problem is still there.
Physically remove it. Don't just map 0 it.
I did this and my under boost went away. Turned out to be a simple setting in the JB4.
Did you say you have new turbos?

WM

Yes I think removing it is a good idea if I'm not mistaken map 0 no longer completely bypasses the jb4. I'll try this and see if the codes come back again.
Yes turbos are about 8 months old I do have a set of RB stage 2 turbos ready to go on in the new year but want the car running spot on before they go on hence why I replaced all injectors as well

[E92 420]

Originally Posted by nicktyler

I can imagine why you are going grey over this as you seem to have covered every possibility.

The only other thing I can think of is sticky waste gates or actuators. Are the symptoms consistent and easily replicated or a bit random?

It's pretty easily replicated really. If I go WOT in 3rd or 4th gear from 3000rpm upwards then I will get the the boost oscillations every time! And the car jus doesn't feel as fast or responsive as it should/did

Sticky Waste gates are a possibility, I have been running 15.7 psi on map 3 with meth disabled since the turbos went on so they haven't had the easiest of lives!

I'm starting to think its a software issue not a hardware problem.
Iv been speaking with DMS and am thinking of doing away with the jb4 completely once the stage 2 RBs are on and let them do a custom tune see if it's any better

[nicktyler]

15.7 psi with no meth is pretty high isn't it? This is a long shot but how are your intake temps? Maybe the engine is running too lean and almost detonating, beyond the scope of retarding the timing at such high boost? Then cutting the fuel/boost or something for a moment until back in the parameters, then repeating?

That could result in the power and boost fluctuations?

[E92 420]

Originally Posted by nicktyler

15.7 psi with no meth is pretty high isn't it? This is a long shot but how are your intake temps? Maybe the engine is running too lean and almost detonating, beyond the scope of retarding the timing at such high boost? Then cutting the fuel/boost or something for a moment until back in the parameters, then repeating?

That could result in the power and boost fluctuations?

Yes it is high for stock turbos I wouldn't really recommend it unless you know your gona be halfing the life of them. Intake temps start at around 68 and end up around 113 on a WOT in 3rd from 2000rpm to 7000rpm. I have 6 cylinder logging and timing is set at 8.5 degrees max and I don't get any timing pulls on any cylinders or throttle closures. The flash has been tweaked to run a little rich up top.

It's strange how when I first got the jb4 with no other mods or the backend flash it was fine for a month and then it just started causing these issues

[windymissile]

How does your aftermarket intercooler connect to the charge air pipe from the turbos? Does it use the oem type connector or pipe and clamp type..?

WM

[E92 420]

Originally Posted by windymissile

How does your aftermarket intercooler connect to the charge air pipe from the turbos? Does it use the oem type connector or pipe and clamp type..?

WM

It uses pipe and clamp type with silicone hoses

[jwilliams]

This may sound stupid and a bit simple but i had the same plugs as you a while back. Had starting issues and engine lights. Went back to the stock plugs and it has been fine for 4 months now.

[old grey steve]

Plugs correct ones are a must BMW run Bosch, deviating away from these can create annoying issues

29f4 29f5 can throw you, we've done walnut blasting on a car last week with this very 2 codes and I know the codes well post walnut blasting code reset engine adaptations re set car run perfectly. No faults returned.

Seen injectors fitted coded to be the issue due to coding issues/not re setting adaptations.

But issues on these cars can gave leave you scratching your head, misfires on these can be anything therefore sometimes there is a time when more I depth diag is required.

[E92 420]

Originally Posted by jordon335

This may sound stupid and a bit simple but i had the same plugs as you a while back. Had starting issues and engine lights. Went back to the stock plugs and it has been fine for 4 months now.

What did you gap the plugs to?

[E92 420]

Originally Posted by old grey steve

Plugs correct ones are a must BMW run Bosch, deviating away from these can create annoying issues

29f4 29f5 can throw you, we've done walnut blasting on a car last week with this very 2 codes and I know the codes well post walnut blasting code reset engine adaptations re set car run perfectly. No faults returned.

Seen injectors fitted coded to be the issue due to coding issues/not re setting adaptations.

But issues on these cars can gave leave you scratching your head, misfires on these can be anything therefore sometimes there is a time when more I depth diag is required.

So the car you worked on didn't have catless DPs and still threw the DP codes?

Yea this is leaving me scratching my head alright!

Iv spoken to evolve again on a few occasions to see weather they could help diagnose these issues or if they could recommend anyone that can help and they said no! Was a little suprised at this If I'm honest.

And on a side note iv had Birds clean the intake valves so this can be ruled out as well

[old grey steve]

Originally Posted by E92 420

So the car you worked on didn't have catless DPs and still threw the DP codes?

Yea this is leaving me scratching my head alright!

Iv spoken to evolve again on a few occasions to see weather they could help diagnose these issues or if they could recommend anyone that can help and they said no! Was a little suprised at this If I'm honest.

And on a side note iv had Birds clean the intake valves so this can be ruled out as well

29F4 / 29F5 are codes relating to a fault there not specific to CAT Less downpipes the codes show CAT Converter/Conversion 1 & 2 and relate to the sensors efficiency therefore they'll show as faulting regardless as to whether an individual car has CAT Less downpipes fitted and relates to a recorded incident seen by the sensors in a nut shell. Carbon build up will create an issue too as we have seen so never assume its a straight sensor fault(though they do go down and are easily damaged when removing replacing them on a CAT Less install)