[BADS335]

Ok, so I went to the track the other day, pretty sure I got some crap race gas. Car had serious KR at various boost and spark levels. Then the car was missfiring. Most noticably at idle. I just inspected the plug (code calls out cylinder 3) and it looked fine. I just swapped them a few weeks ago. Swapped out cylinder 2 and 3 coil packs (counting from front of engine/car to back) and the code did not move. I am now thinking the crap fuel fouled an injector. Has anyone experienced this? I will do some research, but is there a write up on how to swap injectors? I will be pretty pissed if that gas messed it up. Oh and last time to the dealer (I think Nov) I was told I have the latest HPFP. But I really do not think it is pump related since it pulls the same cylinder code every time.

Thanks

[GeorgiaTech335coupe]

I highly doubt the gas messed up your injector. It was probably on its way out. The problem with swapping injectors is that they need to be coded. The physical part of swapping/replacing injectors is very easy, but without coding them they won't run properly and can cause misfires just from not being coded so it won't help much.

[BADS335]

I have the software for coding. So I can swap injectors and code them then see if the engine code moves. Assuming I can figure out the coding software properly.

Thanks

[GeorgiaTech335coupe]

The basic process for removing injectors is: remove ac filter/cowl/engine cover, remove coils on injectors to be swapped (this makes room to work), remove ecu connection to injector, loosen nut on flared fuel piping that connects fuel rail to injector (let pressure subside before removing completely), completely loosen nuts on each side and remove small pipe, cover openings with rag (car will randomly squirt fuel out and it will get you in the face), remove bolt that holds bracket that pushes a group of 3 injectors down, remove bracket, pull injector out. From what I remember that is the basic steps. Overall it is not that difficult. I could have forgotten some steps.

[JamesM3M5]

TIS states the seals are used after one single heat cycle. You should replace the seal and decoupling element any time the injector is installed and run.

[BADS335]

Originally Posted by JamesM3M5

TIS states the seals are used after one single heat cycle. You should replace the seal and decoupling element any time the injector is installed and run.

I was affraid of this. Same with diesel engines.

Any way to make sure the injector is indeed the issue before I drop $150 on a new one?

[BADS335]

Ok, new injector is in and coded...still missing, still 10703 after resetting the code. I am totally lost and annoyed.

[BADS335]

Any suggestions?

[BADS335]

I swapped coils again to no avail. It is dedicated to one cylinder. What else can I do?

[GeorgiaTech335coupe]

So cylinder 3 has a new coil, plug and injector now and is still misfiring?

[Lulz_M3]

Maybe a valve issue, how many miles? Have you cleaned the valves yet?

[BADS335]

GeorgiaTech: Correct
Lulz: 44k miles...no I have not had the valves cleaned.

[BADS335]

Ok, I am going to do a valve cleaning this weekend. Last resort before dealer. I am lost and frustrated. It needs to be done regardless so I will not be as frustrated if it doesn't work as I am for buying an injector for no reason.

Thanks for all the feedback and I am open to any other suggestions. I will update the thread and probably do a write up on my work.

[enrita]

i guess you already tried removing any tune you might have?

[BADS335]

Originally Posted by enrita

i guess you already tried removing any tune you might have?

Yes. I put the ProCede in bypass mode. If cleaning the valves does not work, I will remove the unit completely and see if that helps too. But this is not something that came up after installation or a tune change. It was running fine with it in. Actually, it has been getting progressively worse.

[CSL_E36]

I hope the walnut blast cures your issue, it would def push me to get that done, as I am in your shoes and running out of patience.

[BADS335]

Originally Posted by 96LTWM3

I hope the walnut blast cures your issue, it would def push me to get that done, as I am in your shoes and running out of patience.

Yeah, I'm losing it.

[Simple5]

Originally Posted by BADS335

Yeah, I'm losing it.

Bro I am in the same boat as you. Cylinder 3 misfire with a JB4. Swapped out all the plugs: nothing, swapped out all the coils: nothing, and now I will try to install another injector in it's place if that doesn't work valve cleaning like you then like you, if that doesn't work, last resort is the dealer...

[enrita]

Originally Posted by BADS335

Yes. I put the ProCede in bypass mode. If cleaning the valves does not work, I will remove the unit completely and see if that helps too. But this is not something that came up after installation or a tune change. It was running fine with it in. Actually, it has been getting progressively worse.

you should first completely remove the procede and see. if it missfires at idle its unlikely that is caused by the procede but you should remove any variables.

[GeorgiaTech335coupe]

Originally Posted by BADS335

Actually, it has been getting progressively worse.

Those words instantly make me think injector becuase that always happened when each one of mine went out.

Did you install the decoupler when you put the injector in?

[BADS335]

Originally Posted by GeorgiaTech335coupe

Those words instantly make me think injector becuase that always happened when each one of mine went out.

Did you install the decoupler when you put the injector in?

Yes, new injector and new decoupling ring. New plugs. Swapped coils. Still the same code.

[Simple5]

I replaced my injector with a used injector and so far so good... she purrs like a kitten. When I removed the old injector it was filthy.. i mean nasty.. looks like it was clogged to hell.

Good luck man. Hope you get sorted out.