Datalog Excessive timing pull?

Aidan335DCT

Lurker
Aug 19, 2023
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Hi guys.
Yesterday, my n54 decided to become a 5 cylinder for a moment but then fixed its self seconds later. the only code I had was a misfire cylinder 1 nothing else.
Did some logs after to see if I could see what was up.
Car is stage 2+ MHD v10 with DP, IC, CP (stock DV).
Car felt fine and boosted fairly well, but there's a fair bit of timing pull. Also some variation in the RPM line.
I've got some parts on the way hopefully will rectify it, index 12s, NGK plugs, PCV valve, and Forge DV. coils were done recently by previous owner about 6k ago.
Only other thing I can think is maybe a bad batch of fuel? was Tesco 99RON. Going to try the 95RON tune today or tomorrow and see if that fixes it else ill be gentle to the car until all new parts are fitted.

Update: I’m thinking it’s a fueling thing tbh as short term fueling trims are whacky as fuck on the new log and it seems to match how it’s messing with timing. Also air fuel ratio takes the piss to go back to 234 when I let off (which is what it should go to instantly im told ) on bank 2 so I’m thinking leaky or faulty injector bank 2
 
Last edited:

Mrmigs2011

New Member
May 23, 2022
9
3
0
To me with the way the afr takes its time to stumble up I'd say you've an injector that possibly doesn't want to close when letting off.

I'd put a fresh set of plugs in,do 1000 miles then pull the plugs and check the tips,this is the best indicator of problems imo,

You want to look for a patch of slanted carbon on the tips and the threads and I'll garantee that's the one giving you grief.
 

Aidan335DCT

Lurker
Aug 19, 2023
13
3
0
To me with the way the afr takes its time to stumble up I'd say you've an injector that possibly doesn't want to close when letting off.

I'd put a fresh set of plugs in,do 1000 miles then pull the plugs and check the tips,this is the best indicator of problems imo,

You want to look for a patch of slanted carbon on the tips and the threads and I'll garantee that's the one giving you grief.
yeah I agree, and others ive spoke too do too! especially bank 2. Once my new injectors are tested, bank 2 will be replaced instantly. Re the misfire, I tried it today for 2 runs and it didn't happen! However I daren't do any more testing with leaky injectors, don't wanna blow the motor after all. Im away next week which is when they're tested, so I'll be using my other car (330d e90) for this period while my injectors are tested. I think what fixed it was lowering plug gap and tightening them with a torque wrench not just guessing. Will report back when she's ready for some more hard testing :)
 

Mrmigs2011

New Member
May 23, 2022
9
3
0
yeah I agree, and others ive spoke too do too! especially bank 2. Once my new injectors are tested, bank 2 will be replaced instantly. Re the misfire, I tried it today for 2 runs and it didn't happen! However I daren't do any more testing with leaky injectors, don't wanna blow the motor after all. Im away next week which is when they're tested, so I'll be using my other car (330d e90) for this period while my injectors are tested. I think what fixed it was lowering plug gap and tightening them with a torque wrench not just guessing. Will report back when she's ready for some more hard testing :)
Will be interesting to see how you get on!

They are very tempremental at times !

Won't be long and itl be back to perfect health 😁
 
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Aidan335DCT

Lurker
Aug 19, 2023
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Will be interesting to see how you get on!

They are very tempremental at times !

Won't be long and itl be back to perfect health 😁
fingers crossed these used index 12s work if not I can just return them, could be nice to have the car working had it about 3 months and it worked for about 2 weeks of that so far lol. Still got the AC seals causing the car to leak and washer fluid leak to deal with. Least I've learnt a bit about working on cars, my 330d worked to well to learn anything.