[FrankHop]

Greetings everybody,

I'm hoping such topic won't make you feel as dreary, but I invested huge amount of time for the culprit, still can't be even 50% sure what's happening.

car's a 09 335i, with cobb stage 2+ tune, FMIC+catless DP, car runs great, no vibrations, no hesitation on WOT.

and morning starts looks okay, no long cranks, with a tiny bit up and downs for the rpm for seconds.

(Every cold starts after sitting for like more than an hour or so, not as long as sitting overnight, I might get perfect starts.)

but if after a drive at least for like 30mins, if I parked and want a warm start, also no long cranks, but it shakes like a total nightmare and throws the P2AAF fuel pump plausibility and cylinder#1 misifre codes, sometimes probably an ses light.

so far due to my research, such symptom has nothing to do (?) with the HPFP. and I had a new LPFP about 20000miles ago.

Plus new plugs and coils days ago.

also I think the water pump works fine (will further check), and new coolant sensor came in a month ago.

I do have a catch can but will see if it's actually carbon buildup next week when I have time.

So I'm worrying if it's really the injectors, especially for cyl#1. But thing made me even crazier is that mainly I'm seeing people with failing injectors suffering from COLD STARTS.


Tired. Now I'm not even demanding to be more sure of this problem, just want to hear your thoughts and have better sleep with your support.

[Equinox2k]

Cylinder #1 injector is leaking.

[Saif2018]

Originally Posted by FrankHop

Greetings everybody,

I'm hoping such topic won't make you feel as dreary, but I invested huge amount of time for the culprit, still can't be even 50% sure what's happening.

car's a 09 335i, with cobb stage 2+ tune, FMIC+catless DP, car runs great, no vibrations, no hesitation on WOT.

and morning starts looks okay, no long cranks, with a tiny bit up and downs for the rpm for seconds.

(Every cold starts after sitting for like more than an hour or so, not as long as sitting overnight, I might get perfect starts.)

but if after a drive at least for like 30mins, if I parked and want a warm start, also no long cranks, but it shakes like a total nightmare and throws the P2AAF fuel pump plausibility and cylinder#1 misifre codes, sometimes probably an ses light.

so far due to my research, such symptom has nothing to do (?) with the HPFP. and I had a new LPFP about 20000miles ago.

Plus new plugs and coils days ago.

also I think the water pump works fine (will further check), and new coolant sensor came in a month ago.

I do have a catch can but will see if it's actually carbon buildup next week when I have time.

So I'm worrying if it's really the injectors, especially for cyl#1. But thing made me even crazier is that mainly I'm seeing people with failing injectors suffering from COLD STARTS.


Tired. Now I'm not even demanding to be more sure of this problem, just want to hear your thoughts and have better sleep with your support.

Swap the Cylinder 1 injector with another cylinder, replace seals and see if the issue follows

[Bimmer_Bro]

Originally Posted by FrankHop

Greetings everybody,

I'm hoping such topic won't make you feel as dreary, but I invested huge amount of time for the culprit, still can't be even 50% sure what's happening.

car's a 09 335i, with cobb stage 2+ tune, FMIC+catless DP, car runs great, no vibrations, no hesitation on WOT.

and morning starts looks okay, no long cranks, with a tiny bit up and downs for the rpm for seconds.

(Every cold starts after sitting for like more than an hour or so, not as long as sitting overnight, I might get perfect starts.)

but if after a drive at least for like 30mins, if I parked and want a warm start, also no long cranks, but it shakes like a total nightmare and throws the P2AAF fuel pump plausibility and cylinder#1 misifre codes, sometimes probably an ses light.

so far due to my research, such symptom has nothing to do (?) with the HPFP. and I had a new LPFP about 20000miles ago.

Plus new plugs and coils days ago.

also I think the water pump works fine (will further check), and new coolant sensor came in a month ago.

I do have a catch can but will see if it's actually carbon buildup next week when I have time.

So I'm worrying if it's really the injectors, especially for cyl#1. But thing made me even crazier is that mainly I'm seeing people with failing injectors suffering from COLD STARTS.


Tired. Now I'm not even demanding to be more sure of this problem, just want to hear your thoughts and have better sleep with your support.

I would park the car overnight. Do not start the car the next morning. Take our #1 plug and see if it's wet with fuel. This will tell you if that injector is leaking or not.

[FrankHop]

thank you guys. guess at least I have to find 3 index 12s for bank #1. There's really nothing else could be blamed of except the injectors.

[335xiE90]

Originally Posted by Bimmer_Bro

I would park the car overnight. Do not start the car the next morning. Take our #1 plug and see if it's wet with fuel. This will tell you if that injector is leaking or not.

This is what I did to diagnose my cyl 1 misfire and found a leaky injector was the culprit. To confirm I pulled the injector out, reinstalled it and disconnected all the injectors/spark plugs connectors. I then turned the car over to build pressure and sure enough the injector was pissing out fuel!! I wouldn't recommend pulling the injector without the replacement O-ring and decouplers though.

[FrankHop]

Originally Posted by 335xiE90

This is what I did to diagnose my cyl 1 misfire and found a leaky injector was the culprit. To confirm I pulled the injector out, reinstalled it and disconnected all the injectors/spark plugs connectors. I then turned the car over to build pressure and sure enough the injector was pissing out fuel!! I wouldn't recommend pulling the injector without the replacement O-ring and decouplers though.

Much appreciate for the suggestion! Just bought bunch of o-rings and decouplers for the sake of checking and probably when swapping to used index 12s.

Did you have any warm start symptoms with your bad cyl1 injector?

[335xiE90]

Originally Posted by FrankHop

Much appreciate for the suggestion! Just bought bunch of o-rings and decouplers for the sake of checking and probably when swapping to used index 12s.

Did you have any warm start symptoms with your bad cyl1 injector?

Well my situation was odd. I had a misfire only at high loads and it was due to both a leaky injector and a bad install by the dealer. They used the same o-ring and did not reinstall the decoupler. Then they over torqued the injector hold down clamp and this caused it to bottom out and not have much holding strength. When my car misfired it must have shifted the injector because the freggin tab that locates the injector (welded on!) broke off!

Fast forward to me buying a used index 12 from a shady person. Go figure that injector pissed out fuel from the start. My car wouldn't idle at all and threw misfires in cyl 1 2 3 . This led me to test all my injectors and sure enough the new index 12 was crap after further testing. Luckily I had someone local who had a 12 laying around and that one has been working great. I'll never install another injector without first testing it out.

[FrankHop]

Originally Posted by 335xiE90

Well my situation was odd. I had a misfire only at high loads and it was due to both a leaky injector and a bad install by the dealer. They used the same o-ring and did not reinstall the decoupler. Then they over torqued the injector hold down clamp and this caused it to bottom out and not have much holding strength. When my car misfired it must have shifted the injector because the freggin tab that locates the injector (welded on!) broke off!

Fast forward to me buying a used index 12 from a shady person. Go figure that injector pissed out fuel from the start. My car wouldn't idle at all and threw misfires in cyl 1 2 3 . This led me to test all my injectors and sure enough the new index 12 was crap after further testing. Luckily I had someone local who had a 12 laying around and that one has been working great. I'll never install another injector without first testing it out.

Thanks for sharing! It's innteresting because my previous issue in 2016 with stumbling misfire under high load was, related to LPFP.

I just replaced 3 index 12s for Bank#1 and the warm start symptoms are much alleviated, but its still there, like humping (not long crank), hump hump hump after pressing start button for like 10 seconds then it smooth out all by itself. It's been alleviated so the cynlinder #1 misfire code never shown up, but the P2AAF fuel pump plausibility code is still there, . I know that my coils are mixed brands, would it be the final culprit?

[335xiE90]

Originally Posted by FrankHop

Thanks for sharing! It's innteresting because my previous issue in 2016 with stumbling misfire under high load was, related to LPFP.

I just replaced 3 index 12s for Bank#1 and the warm start symptoms are much alleviated, but its still there, like humping (not long crank), hump hump hump after pressing start button for like 10 seconds then it smooth out all by itself. It's been alleviated so the cynlinder #1 misfire code never shown up, but the P2AAF fuel pump plausibility code is still there, . I know that my coils are mixed brands, would it be the final culprit?

I'd have to defer to someone else with that one. I'm having that same P2AAF listed in my shadow codes but pro tools shows nothing. My car runs absolutely mint. I've yet to notice it stumble even once. Is your code showing up in the shadow code area?

[FrankHop]

Originally Posted by 335xiE90

I'd have to defer to someone else with that one. I'm having that same P2AAF listed in my shadow codes but pro tools shows nothing. My car runs absolutely mint. I've yet to notice it stumble even once. Is your code showing up in the shadow code area?

yo man, I'm not sure whether if it's really in the shadow code area becaue I read that code via my tiny, ancient cobb gadget, it just shows every existing codes.

I was thinking like better to post an update after I can pull a log for a 30 min drive. So it turns out that, now it's the cyl #6 actually has way more misfires (but not enough to lit the engine light), and meanwhile injector #6 has significantly lower electric charge than other 5, by at most 50 volts, not sure what is actually happening, but I guess a few more days of diet or instant noodles would fix this issue by bringing index12s to bank #2 and a whole fresh set of Dinan coil pack

[whyzee125]

Yup, sounds like all injectors were worn with #1 being the worst. A full set of 6 index 12's should have you running nicely. Out of curiosity, which index were your old injectors?

[FrankHop]

Originally Posted by whyzee125

Yup, sounds like all injectors were worn with #1 being the worst. A full set of 6 index 12's should have you running nicely. Out of curiosity, which index were your old injectors?

Yeah totally agree that they all need to be replaced.

I only provided the new parts and fund to a trusted local indie to do the job and totally forgot to ask them the previous index #, I will keep it update after swapping bank#2’s.