[AndrewC1989]

For the past few weeks if not months my JB4 335 has been going from map 5, into map 4 and an SES light is coming on.
This only occurs WOT towards the end of 3rd/4th gear. Highboost, highspeed. I have been getting misfire codes across different Cyl's and SES lights and even a 30FF but this time it is only a #6 code. I recently replaced two injectors so I decided to just change all the plugs and coils and go from there seeing as this was the cheapest place to start.

Today I got my 335 back from the shop after replacing all of the plugs, coils. Car also needed a new battery. It felt like it ran well but would get a tiny bit of a blip at idle. Nothing really noticeable just a small fluctuation between 500-700rpm. Car has been flawless below 60mph even really getting on the gas WOT. Car is FBO + JB4 g5. Map 5.

So tonight i did a pull from 60 to the end of 4th gear and the Jb4 put the car in map 4 and a SES light came on. No flashing. When pressing in the gas pedal after this occurred the car would shake and would not accelerate normally. After turning the car on and off twice the SES light went away and the car resumed normal function. The Jb4 only showed 29d2 - Misfire Cyl 6.

Like i said all plugs and coils were changed yesterday and injectors 1 and 6 were replaced recently. Intake valve cleaning was done less than 10,000 miles ago. Any ideas? What could cause a misfire besides plugs coils and injectors? Doubt it's a leaking head gasket because it only shows one Cyl misfiring not multiple ones.

No rough idle
HPFP replaced a few times in the past
Plugs and coils are new
Injectors 1+6 are new
Walnut blast was done recently
Occurs only at higher speeds/high boost - Has never occurred with Jb4 shut off (Map 0)

What actually happens:
WOT till the tail end of 4th gear in map 5
Feel a misfire and see boost drop
SES light does not flash but turns on
I check my maps and see the car has put itself in map 4
Car shakes when pressing throttle
Restarting car makes shaking and SES light go away
Problem and symptoms are non existant until the process is repeated

UPDATE:

Hear what sounds like wastegate rattle (i think)
WOT pulls in map 0 produced no problems
WOT pulls in map 1 got me into map 4 again. no lights. no codes.

[tc535i]

just one injector? did you recode it?

[AndrewC1989]

Originally Posted by tc535i

just one injector? did you recode it?

Injector 1 was replaced a few months ago when the car would rough at idle. This was done by bmw. Same issue with Injector 6 about a month ago and it was replaced by helix in Philly. I'm pretty sure they coded it, they do good work there and see n54's all the time.

[tc535i]

could just be bad gas

try maps 1 and 0 and see if you can replicate the misfire

[AndrewC1989]

Originally Posted by tc535i

could just be bad gas

try maps 1 and 0 and see if you can replicate the misfire

I will do that on my way home in about 2 hours.
I'll also clear the code and see what (if anything) comes back.

I should also add in that this problem has been occurring for weeks if not longer (and across multiple cylinders)
so i doubt it's just a bad tank of gas.

[AndrewC1989]

Originally Posted by tc535i

could just be bad gas

try maps 1 and 0 and see if you can replicate the misfire

Map 0 - Ran 2-4 WOT. Nothing
Map 1- Ran 2-3. 4500/5000 in 3rd the car went into map 4. No lights no codes.

Also i can hear what i think is wastegate rattle. windows down going slow in 1st gear as boost builds i hear a buzzing like sound. It does not sound like it's coming from under the hood though it sounds like its coming from under the car. anyways i did not have my go pro handy and im not going to take an iphone video of windnoise so here is what it sounds like at idle under the hood and from the exhaust.

[tc535i]

what plugs and coils did you put in

[tc535i]

Originally Posted by comacow02

I will do that on my way home in about 2 hours.
I'll also clear the code and see what (if anything) comes back.

I should also add in that this problem has been occurring for weeks if not longer (and across multiple cylinders)
so i doubt it's just a bad tank of gas.

oh, multiple cylinders? I thought it was JUST on 6.

hmm

[AndrewC1989]

Originally Posted by tc535i

what plugs and coils did you put in

standard bmw ones, nothing cheap

[AndrewC1989]

Originally Posted by tc535i

oh, multiple cylinders? I thought it was JUST on 6.

hmm

this last time it only said #6. before doing the recent work i had misfires across all of them.

[AndrewC1989]

update. im annoyed with my car. heres a photo of my interior to remind me why i love this vehicle.

[AndreiJOY]

Man, this situation is exactly like mine. plugs, coils, injectors all new. misfire cylinder 6 under WOT, stock car.
I've made a list of "need to check" parts, but i'm very busy this days, can't do nothing for it.

I will share with you
-check and clean TMAP sensor, maybe swap it.
-clean vanos solenoids (intake+exhaust)
-could be also a bad O2 sensor (the one before catalyst, on the exhaust pipe for last 3 cylinders)

Please, if you find a solution, can you share it with me? Maybe a pm, i will not find this thread anymore when i will be online next time.

Cheers,
Andrew.

[JOHNNY-5]

I had some what of the same issue, misfires on multiple cylinders. Did the usual plugs, and coils and swaps. Cleaned both TMAP sensors and vanos sensors. Still misfiring.

Replaced my TMAP sensor on the intake manifold and solved the problem.

Not saying this will fix your issue, but worth a try.

[davidwarren]

Originally Posted by Johnny-Walker

I had some what of the same issue, misfires on multiple cylinders. Did the usual plugs, and coils and swaps. Cleaned both TMAP sensors and vanos sensors. Still misfiring.

Replaced my TMAP sensor on the intake manifold and solved the problem.

Not saying this will fix your issue, but worth a try.

sorry for the old bump, but you changed the tmap on the manifold and not the charge pipe, right?

[JOHNNY-5]

Originally Posted by davidwarren

sorry for the old bump, but you changed the tmap on the manifold and not the charge pipe, right?

Correct, I changed the TMAP on top of the intake manifold and it fixed my misfire issue.