[f87king]

New Plugs, Coils, Swapped Injectors around (All Index 12) New Valve Cover and Gasket, Cleaned Throttle Body, Walnut Blasted, New HPFP, all in the last 4 weeks trying to eliminate this misfire. Compression test 170-175 all around. Consistent combustion misfire cylinder 1. Could it be O2s? I have an MSD81 DME so don't think mosfets are an issue. Someone please help so I can install this turbo kit I don't want to keep throwing money if it's gonna keep misfiring. I got a single turbo kit coming soon but not gonna install it unless its fixed

[NoQuarter]

Why not just check the mosfets? Easy enough compared to all the work you are doing.

[f87king]

Originally Posted by NoQuarter

Why not just check the mosfets? Easy enough compared to all the work you are doing.

Tomorrows job everyone said msd81 didnt have problems

[f87king]

Keep in mind I am good at sourcing parts and do all the work myself and already had a walnut blaster so everything cost me under $300 it's not like I'm throwing money. I had no misfire decided to change my rock auto coils/bosch plugs to ngk 95770 gapped at .18/delphi coils and changed valve cover and then all of a sudden misfire changed to a new valve cover have swapped everything from 1 multiple times and sticks to 1 good compression logs show o2s perhaps someone let me know what they see

http://datazap.me/u/tomhondros/misfi...-20&mark=34-48

[robertwhamm]

I am pretty much going through the same problem. My car has cylinder 3 and 4 misfires under load and high RPM that I am currently trying to resolve. So far I have done:

Coils
Plugs
Index 12 Injectors
Valve cover and gasket

Next step is walnut blasting

I am also swapping out the Vanos solenoids.

Not sure were to go from here.

[NoQuarter]

I am not familiar with the idea that MSD81 DME has no MOSFET problems.

I am pretty sure my 2008 535 has the MSD81 and I had a bad MOSFET so I replaced all 6.

[robertwhamm]

I am pretty sure if it is a DME issue you get DME error codes.

[NoQuarter]

Originally Posted by robertwhamm

I am pretty sure if it is a DME issue you get DME error codes.

I'm not convinced this is a 100% certainty. Electronic components can be "bad" without being completely bad.

[robertwhamm]

Originally Posted by NoQuarter

I'm not convinced this is a 100% certainty. Electronic components can be "bad" without being completely bad.

Yeah I get that. Do you know what part you ordered for the mosfet? My car has the MSD81 but I am not ruling it out and the parts are cheap to replace.

This is the part I found on a different post but not sure if its the same part for the MSD81 since the thread was about the MSD80's.

https://www.digikey.com/product-deta...MCT-ND/1566830

[NoQuarter]

Originally Posted by robertwhamm

Yeah I get that. Do you know what part you ordered for the mosfet? My car has the MSD81 but I am not ruling it out and the parts are cheap to replace.

This is the part I found on a different post but not sure if its the same part for the MSD81 since the thread was about the MSD80's.

https://www.digikey.com/product-deta...MCT-ND/1566830

That's the same one I used.

[robertwhamm]

Originally Posted by NoQuarter

That's the same one I used.

I went ahead and ordered 6.

[f87king]

Originally Posted by NoQuarter

I'm not convinced this is a 100% certainty. Electronic components can be "bad" without being completely bad.

Getting mosfets tested today. Next thing is O2 sensors I'm running lean not sure why

[robertwhamm]

Originally Posted by e92335xi

Getting mosfets tested today. Next thing is O2 sensors I'm running lean not sure why

How did the mosfets testing go?

[f87king]

Originally Posted by robertwhamm

How did the mosfets testing go?

All tested well going back to bosch plugs

[itsmehtim]

Having same issue did the plugs coils and injecors

[f87king]

Originally Posted by itsmehtim

Having same issue did the plugs coils and injecors

Wasn't misfiring before my plugs so putting stock ones back

[f87king]

Originally Posted by e92335xi

Wasn't misfiring before my plugs so putting stock ones back

New plugs fixed so far #fuckngk http://datazap.me/u/tomhondros/new-p...lo=6&mark=4-22

[SpeedChamp]

Man I had so many of these mystery misfires... they are a pain.

[f87king]

Originally Posted by SpeedChamp

Man I had so many of these mystery misfires... they are a pain.

Seriously they are I have a single turbo kit in my garage but am trying to fix this issue now I'm having major timing flatline.

[CoolHandLuke]

chasing a misfire on 2+ cylinders also. Only done plugs and coils though. I'm also FBO and the issue started shortly after