[samson1128]

Hey guys, sorry this is a long one but im completely stumped along with a shop and have tried everything, about 3 months ago i decided to pull the trigger on a 07 335i E90 and starting to think it was the worst mistake I've made, at first the car was just not making any boost, and consistently getting 30ff limp mode. At the time the car had a FMIC, DCI, and upgraded charge pipe on mhd stage 1+. Took it to a local shop that had dealt with a lot of n54's to have the turbos replaced, and while they were at it i had them throw some downpipes i had on. And they said the car was all ready to go and on the drive back home i had no issues, turbos hit 18psi and car pulled hard with no misfires at all. But, the next day i hopped in it to go for a test drive, and there was a very hard misfire on cylinder 1 and 3 under load most noticeably around 2500rpm, car was basically undriveable had trouble getting to 60mph. I cleared the codes and it ran on all 6 cylinders and took it back to the shop the next day. And this time, they found out a brand new turbo they put on was faulty, so they replaced it under warranty but the car still had the same misfire. But here's the weird thing, sometimes i would start the car up and it would be perfectly fine, it will hit 16-18psi no problem and not cause me any issues at all. But i could literally just turn the car off to put gas in it, and turn it back on and it would have the same undriveable misfire, and the best way I've found to get rid of it is to leave it sit 15 minutes then drive it again and ill have no issues. While it was in the shop, we also had new spark plugs, coils, and a battery thrown in it just to eliminate those to once again no avail. They took it for a test drive after to see if that would fix it, and while they were test driving it one of the mosfets blew for cylinder 1, which cause the whole bank to shut down. And that's when the shop declined to work on it any longer because they don't deal with stuff like that. So I had the mosfet replaced, and that fixed that problem but still had that misfire. I also noticed that whenever there was a misfire, cylinder 1 was always apart of it but usually it would be two cylinders, I've had every cylinder misfire at least once but cylinder 1 was always apart of it. So i decided to replace cylinder 1's injector as it was an index 1 and I thought that would be the culprit, but no, that did absolutely nothing. So I've tried spark plugs, coils, injectors, even a mosfet change and still have a almost undriveable car at times. Only things i can think of at this point is the DME itself as its and MSD80, or the mhd tune on the car is crap and sometimes it just doesn't like the car I guess. Leaning towards dme, any thoughts on this?

[wahooooman]

Originally Posted by samson1128

Hey guys, sorry this is a long one but im completely stumped along with a shop and have tried everything, about 3 months ago i decided to pull the trigger on a 07 335i E90 and starting to think it was the worst mistake I've made, at first the car was just not making any boost, and consistently getting 30ff limp mode. At the time the car had a FMIC, DCI, and upgraded charge pipe on mhd stage 1+. Took it to a local shop that had dealt with a lot of n54's to have the turbos replaced, and while they were at it i had them throw some downpipes i had on. And they said the car was all ready to go and on the drive back home i had no issues, turbos hit 18psi and car pulled hard with no misfires at all. But, the next day i hopped in it to go for a test drive, and there was a very hard misfire on cylinder 1 and 3 under load most noticeably around 2500rpm, car was basically undriveable had trouble getting to 60mph. I cleared the codes and it ran on all 6 cylinders and took it back to the shop the next day. And this time, they found out a brand new turbo they put on was faulty, so they replaced it under warranty but the car still had the same misfire. But here's the weird thing, sometimes i would start the car up and it would be perfectly fine, it will hit 16-18psi no problem and not cause me any issues at all. But i could literally just turn the car off to put gas in it, and turn it back on and it would have the same undriveable misfire, and the best way I've found to get rid of it is to leave it sit 15 minutes then drive it again and ill have no issues. While it was in the shop, we also had new spark plugs, coils, and a battery thrown in it just to eliminate those to once again no avail. They took it for a test drive after to see if that would fix it, and while they were test driving it one of the mosfets blew for cylinder 1, which cause the whole bank to shut down. And that's when the shop declined to work on it any longer because they don't deal with stuff like that. So I had the mosfet replaced, and that fixed that problem but still had that misfire. I also noticed that whenever there was a misfire, cylinder 1 was always apart of it but usually it would be two cylinders, I've had every cylinder misfire at least once but cylinder 1 was always apart of it. So i decided to replace cylinder 1's injector as it was an index 1 and I thought that would be the culprit, but no, that did absolutely nothing. So I've tried spark plugs, coils, injectors, even a mosfet change and still have a almost undriveable car at times. Only things i can think of at this point is the DME itself as its and MSD80, or the mhd tune on the car is crap and sometimes it just doesn't like the car I guess. Leaning towards dme, any thoughts on this?

Have you flashed to stock to see if the problem continues ? also Gap on plugs ? Have you pressure tested the hot side of the intercooler ?