cfaber

This might be worth a shot..

how deep in the engine is this valve?

Um.. my understanding is the blinking CEL is very bad, either airlock in the fuel line or bad gas, etc. But it's bad enough that it can destroy your cat in your UP.

Interestingly cyl #4 with LWFW or even slightly slighter than stock tends to throw misfires more than anything, many cases of this are on this thread, I've experienced this as well and I've tried swapping everything and replacing the plugs, etc.

it seems that if the problem is related to harmonics within the fuel line between FPR and rail, an analog in line fuel pressure gauge should indicate this (with wild movement at select RPM range)

Hey, are you guys running updated firmware on your Cobb AP? Since upgrading the instances of stutter I've seen have gone down a huge amount.

Your other option is to find a tuner in your area and get some help

yeah

Have you done a leak down test on it yet?

No, it is a recall issue though, and if you haven't had the main fan relay replaced yet I _highly_ recommend you do it before you fry your ECM

does your cooling fan run constantly?

clean MAF and reflash, see if that addresses it.

*nods* but it wasn't the original map.

I'm actually worried about this my self. My original stock map was lost when my AP decided to quit and when they repaired it they shipped me a completely blank one.

Eh? I had this problem right out of the box. You mean K&N is putting way too much oil on the filter?

I'm wondering how much of this issue is MAF getting dirty, at least on my car. Stupid oily K&N cakes the thing in a pretty short time, and if it's getting sketchy readings all the time from that...

"Woohoo! I love hospital parties" - Taco

bah, hipsters just move to what ever is just popular enough. android this year, apple last year. They're just phones that random asshole corporations produce. Get over your selves.

yeah I had the ap in the car at the time but it wasn't hooked up. If I can catch it in time I'll stick it on there. Like I said, it was quick then over and not experienced since.

I think the "bouncing" was just an effect of the ECM trying to keep the car from stalling out as the RPM's dropped to critical levels. So really it was bounce up, then fall back down to stall, the back up again.

yeah no code at all. What I did was start the car (it was already warmed up), back out of a space, quick bit of power then shift to neutral and brake (waiting for the wife). at that point no pedal input just stand on the brake and watched it bounce wildly for a second or two then it went right back to normal.

No CEL, and it was only for a second, if TPS was out of adjustment / reading bad I would think I would see this much more frequently.

So interestingly the stumble is back, Watched tonight with AC on while idling it would bounce down to about 500 RPM's then jump back up to 1500-1700 then dump back down into the low RPM range. This was totally out of the blue.

don't know if this has anything to do with the studder but I recently replaced the gas cap and haven't had a studder since.

TYPE OF STUTTER/STUMBLE Steady throttle/Increasing throttle/Both: steady, at idle, sometimes while falling back to idle. MODS Intake: K&N stock. Exhaust: stock Fuel: 93oct Turbo: stock Engine Management: cobb ap, fuel saver map, but noticed with performance as well Tuner and revision of tune(if you don't mind): MAINTENANCE Sensors changed: gutted STI uppipe /w bung welded closed and resistor. Plugs changed: all Coil Packs changed: switched around, no problems found. OTHER SYMPTOMS Check Engine Light: CEL with misfire on CYL4 Etc: Studder only when AC is on and at idle. RESULTS What has and hasn't worked for you: plugs, oil, filter, MAF cleaning If something worked, how long has it been working for: reflash (temporary or permanent) Noticed this much more after installing new clutch and slighly lighter FW.