misfire crap. any other ideas at all!?!

[volks88]

alright so im getting misfires in 3 and 5. i changed the plugs and gapped to .026. i have new egt's and new 02's. i have swapped out coil packs but misfire continues in those cylinders. i have swapped injectors and also the ignitors. still the same. im getting no codes except for misfires in 3 and 5. this is at idle. if im trying to take the car into boost by stomping on it it just cuts out. help please! let me enjoy my stg3

[exorcet]

have you done a compression and leakdown test?

also what fueling setup are you running?

[volks88]

have you done a compression and leakdown test?

also what fueling setup are you running?

tests were done about 2500 miles ago when the stg3 was installed but not after. EPL fueling

[Audi S4 Turbo]

have you done a compression and leakdown test?

also what fueling setup are you running?

How is your stage 3 doing man?

[elijahallen]

Pressure tested I hope??

[volks88]

Pressure tested I hope??

doing it tomorrow. did a compression test tonight and everything checks out. when i hit 20psi in 3rd it falls on its face and hits limp mode.

[volks88]

would one or two bad coil packs cause misfires in other cylinders? i swapped the coil packs out from cylinder 5 which had 50 misfires with cyl 4 which had 2. when i changed them they both had plenty of misfires. im ready to burn this fucking thing!

[AudiSportB5S4]

yes it would, i had that problem man. look back to one of my threads i was aBOUT TO sell the bitch lol. i had 2 bad coils causing other cylinders to go a little haywire as well. best bet is to swap fresh coils in before buying (if you can) to see if thats the problem, also check coolant temp sensor, doesnt sound like that but make sure you do a good boost check, maybe something is loose under a lot of pressure so do the test at 15-20 psi

[volks88]

yeah i'll boost leak test tonight. when i roll the throttle on it's fine, makes boost fine. when i stomp it it cuts out. im just more concerned with the misfires at idle and if its it or not i need to fix it. coils on the car are probaly very old. it really seems like im not getting good spark when i hammer it. heres why i think this.... after the stage 3 was installed in ran great! then it started to miss and got worse. i changed the plugs and again, ran great. only to do the same thing. changed plugs again after fixing the maf code and it crapped out only faster. to me it seems like an spark issue because why else would the new plugs help and then fade out? it seems like what the new plugs were making up for has finally crapped out completely. thats why im now thinking coil packs??

[AudiSportB5S4]

certianly does LOOK like coilpacks may be your problem. especially if you keep changing the plugs ya know. bro i had the SAME problem! the ppl who fixed it installed 6 new coils and a new coolant temp sensor. oh and 6 new plugs haha

[AudiSportB5S4]

take a looksee at my thread

http://www.audizine.com/forum/showth...ring+continues

[volks88]

also the only codes im getting is random multiple misfires and then basically certain cylinder misfires (3/4/5/6) sometimes 1 and 2 but not always. according to vag when i read blocks 15 and 16 cyl 3 and 5 get the most but its not limited to those cylinders. it jumps around and varies alot.

[The_Jerbel]

Did you properly gap the new plugs? What engine load do you see at idle? Try swapping the coils with some on cylinders that don't misifre. Also try swapping the ICM's and see if the misfires move.

Sounds like you may not be getting requested boost and going into soft limp mode. Do that boost leak test and then go from there.

[drkenan]

I'm having a similar problem (though doesn't sound as bad) and I'm pretty sure that it's from a leaky valve cover gasket fouling out the plugs. Did you check that?

[volks88]

Did you properly gap the new plugs? What engine load do you see at idle? Try swapping the coils with some on cylinders that don't misifre. Also try swapping the ICM's and see if the misfires move.

Sounds like you may not be getting requested boost and going into soft limp mode. Do that boost leak test and then go from there.

gapped new plugs at .025. swapped coils from cylinders that werent misfiring to ones that were and then they both were misfiring. also swapped ICM's with each other and also from another car just to make sure i didnt have 2 bad ones. does 17% sound right?? im pulling that from nowhere really i just thought i remeber seeing that number lol

[zoik]

had similar problem with misfiring. my mechanic changed the plugs, checked the coils, replaced the injectors. it ended up being the ignition control module. i don't know if there is a way to check those though

[The_Jerbel]

He did check those by swapping them with some from another car.

17% sounds right if that's what you are running at idle.

[volks88]

17% sounds right if that's what you are running at idle.

yeah its at 17%. i might just replace all the coils at this point. i dont know if they have ever been changed and its not that bad of a hit. that way i'll have new coils anyway. this is getting really old fast

[volks88]

anyone?

[volks88]

8D0 907 551 M,,2.7l V6/5VT G 0002,
,2480,32.3,970.0,980.0
,2680,82.0,2550.0,1120.0
,3040,128.6,2550.0,1720.0
,3600,185.0,2550.0,2400.0
,4200,183.5,2550.0,2450.0
,4840,165.4,2550.0,2340.0
,5440,151.9,2550.0,2300.0
,6000,140.6,2540.0,2220.0
,6520,130.1,2550.0,2170.0

[AudiSportB5S4]

my idle load is 18.8% right around it stays though.... so are you getting a compressor and a tester tonight or something ?

[volks88]

my idle load is 18.8% right around it stays though.... so are you getting a compressor and a tester tonight or something ?

i just built my tester. whats pissing me off is that if i roll the throttle on lightly i can get it right on its edge of hesitation and its still fairly quick. once i hammer the throttle though it bogs down.

[AudiSportB5S4]

what people told me was that if your having problems during WOT its usually a plug/gap issue. my problem was AFTER WOT, returning to part throttle it would begin to misfire.

[exorcet]

since you've changed plugs several times, how did they look? specifically the ones in the cylinders that are misfiring?

have you logged o2 voltages - maybe you are running too rich? how do the exhaust tips look?

[exorcet]

How is your stage 3 doing man?

good! it was good talking to you tonight -- can't wait to meet up and do some runs.

[The_Jerbel]

Try unplugging the MAF and see how it runs. Of course, only after you have done a pressure test. Also log block 115 as I suggested above.

[Kievskiy]

did you try to swap coil amplifiers? two black chip looking things on top of the airbox, mine did burn at one time, also stop gapping plugs, try the other new set, i got Bosch platin 2 and it works like a champ now !

[s4nicetry]

also the only codes im getting is random multiple misfires and then basically certain cylinder misfires (3/4/5/6) sometimes 1 and 2 but not always. according to vag when i read blocks 15 and 16 cyl 3 and 5 get the most but its not limited to those cylinders. it jumps around and varies alot.

The ICM's can be notoriously problematic in the S4's, if one module is bad and is causing a cylinder or multiple cyl. misfires, then the motor attempting to compensate and adjust can cause misfiring throughout other cylinders in the engine as well not just the cylinders of the faulty ICM. So before you go and change all of the coilpacks out make sure your ICM's are operating correctly first, as that sounds more like your issue to me.

[volks88]

The ICM's can be notoriously problematic in the S4's, if one module is bad and is causing a cylinder or multiple cyl. misfires, then the motor attempting to compensate and adjust can cause misfiring throughout other cylinders in the engine as well not just the cylinders of the faulty ICM. So before you go and change all of the coilpacks out make sure your ICM's are operating correctly first, as that sounds more like your issue to me.

also swapped ICM's with each other and also from another car just to make sure i didnt have 2 bad ones.

unless i had 2 bad and the other car had 2 bad ones i think im ruling those out. thanx tho

[s4nicetry]

unless i had 2 bad and the other car had 2 bad ones i think im ruling those out. thanx tho

Sorry chief I missed that line, coils could certainly be a good possibility, have you checked for air leaks at all?

[volks88]

Sorry chief I missed that line, coils could certainly be a good possibility, have you checked for air leaks at all?

im at the shop right now about to do it. it just seems to me the way that it started was boost leak related. i was entering on the on ramp and in 3rd i was about to shift into 4th (around 6000rpm) and boom, there was a small noise and then the car shuddered. ever since then it hasnt been right and shudders when hitting boost unless i roll the throttle on gently. im really outta ideas and im seriously thinking about parting the car out[O_O]

[AudiSportB5S4]

i got the same way believe me it pissed me off to no end, my thread was misfiring continues about to sell lol. give us your report after a boost leak check certainly sounds like it could be related. have you checked things like IC hoses, maybe a little loose and under boost they are coming off?

[The_Jerbel]

Try this on your ICM's before replacing all the CP's...
ICM testing

[volks88]

ok so no boost leaks. compressions good.fuel pressure is good. swapped out the n75 with a MBC and turned down the boost to 14psi. car has a hesitation at 36,3700 rpm until 4200 rpm's. then quits. o2's are good, maf readings in gps are good. the thing at those rpms is that when we were watching vag, when it hit that spot it was pulling as much as 8 degrees timing, then when it was past 4200 it returned to normal. now when i turn the boost up it does this but in a more significant manner. i just left the shop and when the car was cold i couldnt get it to miss at those rpm's. as the car got warmer it got progressively worse and it started doing it at exactly those rpm's. a sensor maybe? software issues?

[The_Jerbel]

you replaced the CTS yet?

[volks88]

you replaced the CTS yet?

nope haha i was just searching and reading about that. will replace tomorrow

[volks88]

CTS replaced and no help at all. i'll give this problem untill the weekend. if its not figured out im probably going to cut my losses and part the entire car.

[The_Jerbel]

Try testing your ICM's like in the link I gave you above.

[volks88]

ok so after all that it was my coil packs. once warm they were the problem. swapped them out and its good to go. i will never believe anyone if they tell me bad coil packs cannot make other cylinders misfire. thanx everyone for the advice, problem solved

[AudiSportB5S4]

good to hear. it was my problem as well... they replaced all 6 just for insurance because you never know lol. now go enjoy that beastbeast