fuel pump acting up?

[Jwguerrero3]

I have a 08 speed3 with front mount, intake, cobb tune, and full catless exhaust and recently cracked the little connection that sits on top of the fuel pump. the car still runs but i got a CEL that read "circuit malfunction cylinder 2" and the car seems to cut that cylinder. To fix that i jsut turn the car off, then turn it back on and its as if nothing happened, so i clear the code and im on my way. side note still waiting for new fuel pump. today while coming home from work i noticed it was misfiring like crazy, sputtering through gears, and all in the same cylinder as the circuit malfunction. my question is there anything else that could be wrong or could it just be that I need to replace the fuel pump. please help.

Sincerely,
Javier Guerrero

 

[chimmike]

you're getting upgraded fp internals, right?

 

[MSMS3]

^This. OP, listen to this man. He speaks truth. With your mods you MUST upgrade that pump. Putting a new stock pump on the car without upgrading the internals is a recipe for disaster. If you have already upgraded the internals in the stock pump on the car now, some might say it is possible that you could use those internals and swap them into your new stock pump. But, not knowing their condition or quality (not all upgrade pump internals are equal), it's better to do it right with new upgraded AutoTech internals.

 

[Jwguerrero3]

I don't have upgrade fuel pump internals because I'm reading the same numbers as if I did have upgraded ones. Some guys around my area consider my car to be a "factory freak" cuz I pull on them with half of what they have lol. The first time I got some kmd's, or whatever they are called' and they were TOO tight and did not fit. But I am looking at getting upgraded internals. But other than that could there be any reason for misfire that anyone may know of.

 

[MSMS3]

Are you actually datalogging or simply visually, real time monitoring the fuel pressure? If you're just watching a digital readout, you can miss significant negative data that would show up on the datalog. A lean out of AFR due to low fuel pressure can happen in less than one second. This dangerous condition might not show up visually on real time monitoring but would be clear as day on the datalog.

Believe us when we say you NEED the pump internals. I ended up with unacceptable fuel rail pressure even with Hypertech and my mods below and had to upgrade. I don't think I would have caught that just by watching a digital readout. Datalogging showed the drop down to 600 or so, with a quick, almost immediate recovery. I would not have noticed that just by looking at a gauge or digital readout.

Having said that, we really need to know the exact CEL code number, rather than your interpretation of it, since what you describe could be covered by several different codes. I'm guessing (and that is not a good way to diagnose) that your code MIGHT be P0202, which would indicate a fuel injector problem on cylinder 2. It could be the injector going bad, or the injector seal, or high resistence, a short or open circuit on the wiring to the cylinder 2 injector, etc. A datalog with proper PID's selected would tell us more, but knowing that exact CEL might exclude some things and help us move in the right direction.