My Cyl.3 misfire suggestions PLEASE

[Boosted_N54]

for the past week every morning when i start the car it misfires on Cyl.3 with a little rough idle then it calms down. today i decided to change all 6 spark plugs and all 6 coil packs and when i started up the car i scanned it for codes with my cobb AP and i got the misfire cyl.3 again so i deleted the code and took the car for a drive after a while when it warmed up i went WOT i pushed the car hard and i scanned the car for codes and it did not find any code i then shut off the car started up the car searched for codes again and no codes. all i can say is the car felt really good when i pushed it with the new plugs and coils. what do you guys think it can be? i have a feeling tomorrow morning when i start up the car it might give me the misfire again?

i have 65,000 miles i have done walnut blasting in the past i have Cobb AP on STAGE 0 ( stock ) and a CAI all spark plugs and coil pack were purchased from my BMW dealership . my old spark plugs looked bad

can it be the vanos solenoids??

should i reset my ECU with my COBB AP ?

[Boosted_N54]

Originally Posted by Ian///M

You sure you cleared the code after the last time it was started with the old plugs & coils?

Could be injector

yea . what other symptoms would i see if it was the injector?

[RaceTruk]

misfire can be caused by spark, coil, or injector.
you're supposed to swap sparks to a different cylinder,
if it moved, then its that spark,
if it didnt, you move the coil to another cylinder.
if it moved its you coil,
if it didnt, then you try injector.
new injectors require coding though for your car.

not that 65k miles you shouldn't get all new sparks and coils, but that wasn't necessary to rectify or even diagnose this problem

[Boosted_N54]

Originally Posted by RaceTruk

misfire can be caused by spark, coil, or injector.
you're supposed to swap sparks to a different cylinder,
if it moved, then its that spark,
if it didnt, you move the coil to another cylinder.
if it moved its you coil,
if it didnt, then you try injector.
new injectors require coding though for your car.

not that 65k miles you shouldn't get all new sparks and coils, but that wasn't necessary to rectify or even diagnose this problem

Well I just wanted to change all the plugs and the the coil it packs because I'm going fbo just to be on the safe side

[Garabins]

If you have new plugs and coils, then your injector is probably leaking. Let the car sit over night, and pull #3 plug. If the plug is wet with fuel, then your injector is leaking.

[Boosted_N54]

So like I said today this morning when I started up the car I got the misfire cylinder 3 again but after awhile it goes away and it does it come back after I deleted it even if I shut off the car for half an hour and restart the car it won't show up if it is the fuel injectors what would be the symptoms how would the car react because after when I Drive the car and drives normal really good

[Boosted_N54]

So like I said I woke up this morning I start up the car and I got the misfire cylinder 3 again after I deleted it , it never came back i even shut off the car for half an hour restart her up again and it didn't show any codes. If it is the fuel injector what symptoms should it have? How would the car react? Because the car runs fine even when I go wot

[Garabins]

Originally Posted by Da _Grk_Tuner

So like I said today this morning when I started up the car I got the misfire cylinder 3 again but after awhile it goes away and it does it come back after I deleted it even if I shut off the car for half an hour and restart the car it won't show up if it is the fuel injectors what would be the symptoms how would the car react because after when I Drive the car and drives normal really good

Overnight the injector leaks fuel onto the plug, so when you start it up first thing in the morning it will misfire until the plug dries up. When the plugs are dry, the misfire will go away because your injector leak isn’t so bad, but it will get worse overtime. I had the same issue you are having. My car would misfire for 5 minutes every morning and it would be ok for the rest of the day. The injector and misfires will get worse over time...you might want to start saving for new injectors $1,000 from ECS tuning, and $100 to get them coded at the dealership. The install is very simple and straight forward, so you might want to save a bunch of money and do the install yourself.

[Boosted_N54]

Do I have to replace all injectors or that just that 1 ? How much can it be for just one injector? I am going FBO tomorow will this make the case worse?

[vivanapoli806]

Originally Posted by Da _Grk_Tuner

Do I have to replace all injectors or that just that 1 ? How much can it be for just one injector? I am going FBO tomorow will this make the case worse?

I would get the misfire taken care of before u start adding more power and bolt ons. I think u have to replace either all 6 or at least 3 at a time. Get in contact with vendors on here like Phil@reeves and getbmwparts.

[Boosted_N54]

Originally Posted by vivanapoli806

I would get the misfire taken care of before u start adding more power and bolt ons. I think u have to replace either all 6 or at least 3 at a time. Get in contact with vendors on here like Phil@reeves and getbmwparts.

Why not only 1 injector why do I have to replace all of them or 3 at a time?

[Boosted_N54]

What do I need to code my injectors my self

[vivanapoli806]

Originally Posted by Da _Grk_Tuner

What do I need to code my injectors my self

Idk about coding them. But there are two banks. Bank 1 and bank 2. Each one has 3 injectors and need to be replaced together. It's crazy how many things have to be coded for this car when u replace them.

[Tiago@VRSF]

You can diagnose the injector by moving it within the same bank. If that misfire occurs in the new cyl, you'll know if it's the injector.

I'd post up a log so we can see if there's anything obvious you may have overlooked.

[Boosted_N54]

I guess this might turn out to be good new. 3 days ago I put some gas Shell 93oct and ever since then I don't get my misfire cyl.3 no more. cross my fingrrs this is it. can the misfire happen from bad gas? I only put 93oct

[Boosted_N54]

bump

[mike@x-ph.com]

Originally Posted by Socrates.Tii

bump

Socrates first start by swapping the injector and check if the misfire is now on a different cylinder. If so its a bad injector, you do not have to change all three you can change only that injector, mechanic has to coded for you though.
If it is a bad injector let me know.

[rocketpop]

You can get away with changing just the one if its the same model. If your going from the older model to the new model you at least have to all 3 in the same bank.

[Boosted_N54]

I'm just saying that I DONT get the misfire anymore ever since I put some shell v power 93 octane . can It be from bad gas? Although I always put 93oct moble