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View Full Version : what would cause misfires?



goldenchild
01-08-2006, 11:33 AM
ok i just replaced my plugs today and im missing. i also just replaced my coils a few months back. ones from ecs. what the hell else can cause a car to miss. im not runing rich anymore. this is only happening under higher boost levels by the way. yes of course i have em set at .028 and only thing im thinkin is my spark is gettin blown out or my coils are already losin their freakin juice. which ill be super pissed bc i just bought em

goldenchild
01-08-2006, 12:01 PM
http://www.nology.com/power.html

has anyone ran these before is so whats the opinions on em.

k0mpresd
01-08-2006, 12:13 PM
its not your spark being blown out or your coils..unless theyre not seated down properly..it sounds like you have another problem...and you dont need whatever those nology things are..there are lots and lots of vw 1.8t guys running stock coils, unless theyre running standalone and even some of those guys are running stockers

what plugs are you running? and do you have a wideband?

edit: and do you have a vagcom?

goldenchild
01-08-2006, 12:40 PM
i have access to em they r seated right i run the typical ngk bkr7e gapped at .028. i know most guys run stockers but an ignition upgrade isnt a bad thing. i get what ur sayin why waste ur money but if they actually work unlike the plasmas as u stated id be worth it to me to pick up a set

mike-2ptzero
01-08-2006, 01:27 PM
Have you done any logs to see how much adv timing the ecu is asking for and how timing is being pulled?

The stock coils have been used in many cars running up to 30psi and making up to and over 400 whp. So I dont think its a coil issue.

BTW the voltage out of the stock coils is controlled by the chip and set by the ecu. Plus making the gap smaller decreases the voltage and making the gap larger increases the voltage. So dont gap the plugs smaller then you really need.

tontod
01-08-2006, 06:04 PM
mike-2ptzero: I am having similar problems, what logs (blocks) should I take? And the logs should be taken at WOT, right?

mike-2ptzero
01-08-2006, 06:27 PM
Originally posted by tontod
mike-2ptzero: I am having similar problems, what logs (blocks) should I take? And the logs should be taken at WOT, right?

Should be Blocks
003
020

ABTa4t
01-09-2006, 09:56 AM
My fuel injectors were causing my car to misfire, sent the injectors back to RC and they confirmed 2 were bad.

goldenchild
01-09-2006, 10:35 AM
i think mike is right in my situation bc once i set i tback down to 20 psi which is what the file is written for it acts fine

k0mpresd
01-09-2006, 10:41 AM
so why do you think its misfiring? is the cel flashing @ you? done logs?

or is it just because boost drops @ high rpms?

goldenchild
01-09-2006, 11:28 AM
o it flashed and no the boost doesnt drop. it just stops buildin or holdin due to it misfiring. what psi do u run.

k0mpresd
01-09-2006, 11:31 AM
ouch...you def have a issue somewhere

21-22.5 depending on how cold it is outside

goldenchild
01-09-2006, 12:06 PM
22 is where i will see it bairly happen when im holdin it to redline when i up the boost anymore it gets worse

Daft
01-09-2006, 12:10 PM
Originally posted by mike-2ptzero

BTW the voltage out of the stock coils is controlled by the chip and set by the ecu.

Is this true for all B5 cars? I once had a chip that was cutting out at times with random misfires and I knew that the software had a hand in it.

On the AEB's we have that ICM that tends to go bad for some people. I knew that the ICM made the voltage changes but, I didn't know the ECU was still tweaking it that far down the chain.

I've also noticed how the ICM was moved into the coil packs on DBW cars.

k0mpresd
01-09-2006, 12:15 PM
Originally posted by goldenchild
22 is where i will see it bairly happen when im holdin it to redline when i up the boost anymore it gets worse
if your run your turbo @ 22psi and it starts misfiringenough to make the cel flash then you need to stop driving it until you figure out the problem

or buy a 1.8t block

do you have a wideband?

TomRitt18944
01-09-2006, 12:16 PM
sounds more like a fueling issue to me

k0mpresd
01-09-2006, 12:23 PM
Originally posted by TomRitt18944
sounds more like a fueling issue to me
me too...thats why i keep asking if he has a wideband

Daft
01-09-2006, 12:27 PM
Originally posted by TomRitt18944
sounds more like a fueling issue to me

Same here. Sounds like the ECU is seeing knock and pulling boost/timing to cover it's ass.

An ignition misfire is going to be brutal at 22Psi. Were talking some serious bucking.

Knock or pinging at 22Psi would be more likely to result in power loss from timing retard.

goldenchild
01-09-2006, 12:37 PM
it was flashin around 25 psi i simply said u can start to see it when i do 22 and it doesnt happen till right before i shift. i said i have access to the wideband

TomRitt18944
01-09-2006, 12:57 PM
well then whats the a/f on boost at 22psi? i doubt those 440's at 3 bar are going to keep up at 22psi

goldenchild
01-09-2006, 01:04 PM
what injectors are u runin right now? im prob goin to buy a wideband very soon just need to see how much i have left after my clutch and buyin my girl a cell phone...lol...i know

mike-2ptzero
01-09-2006, 01:22 PM
Originally posted by k0mpresd
me too...thats why i keep asking if he has a wideband

He doesn't need a wideband just to see if it is a fuel issue. Even using the VAG to log the 02 readings will do good enough. Plus a wide band can make the car look lean when there is a misfire issue even though the car is running rich during that time. The reason is because the fuel is burning as it goes out of the cylinder and past the wide band 02 sensor if its too close to the cylinder.

k0mpresd
01-09-2006, 01:47 PM
having a wideband in the car is a lot better than having to have a laptop plugged up all the time..

but it sounds like requested/actual boost and o2 readings would be a good thing to log [;)]

TomRitt18944
01-09-2006, 01:52 PM
i''m running 440's at 4 bar aka 505's, i know this isnt enough, which is one reason I'm only running 10psi