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Lazer Viking
04-04-2008, 08:25 PM
99.5 1.8t-
a few weeks ago my car started hesitating when i would get into boost, i could hold the car at 10hg's and then proceed boosting normally with no stubling, so i assumed it was just a boost issue, the it turned into a very obvious missfire under boost, and eventually turned into a missfire even at idle, i diagnosed the problem cyl as #2 and figured it was my icm taking a shit, so i ordered one and waited a week for it, didnt do anything [headbang]

i've checked all the plugs several times and got rid of the missfire at idle, must have just been a spark plug issue, but my missfire under boost is still present
i've unplugged the maf and ran worse, so i ruled that out.
i've disconnected the n75 and ruled that out
still getting a solid cel (dont have a way to get codes read till sunday)
everytime i pull the plugs out they are black and covered in gas

what the hell else could this be ?

mike-2ptzero
04-04-2008, 11:21 PM
99.5 1.8t-
a few weeks ago my car started hesitating when i would get into boost, i could hold the car at 10hg's and then proceed boosting normally with no stubling, so i assumed it was just a boost issue, the it turned into a very obvious missfire under boost, and eventually turned into a missfire even at idle, i diagnosed the problem cyl as #2 and figured it was my icm taking a shit, so i ordered one and waited a week for it, didnt do anything [headbang]

i've checked all the plugs several times and got rid of the missfire at idle, must have just been a spark plug issue, but my missfire under boost is still present
i've unplugged the maf and ran worse, so i ruled that out.
i've disconnected the n75 and ruled that out
still getting a solid cel (dont have a way to get codes read till sunday)
everytime i pull the plugs out they are black and covered in gas

what the hell else could this be ?



Did you move the coils around and see if the misfire changes cylinders?

Have you done a compression check?

Lazer Viking
04-05-2008, 05:29 AM
i have, and the missfire at idle went away when i switched the #2 coil to the #1 cylinder
but it was still missfiring under load

i have not done a compression test, because the car is fine at idle and when driving out of boost, which i think almost rules out dropping a cylinder, correct ?

trailertravis13
04-05-2008, 07:21 AM
I am having this same exact problem! I was going to start a new thread until I saw this. Here is what my car is doing (copied from my thread on AW).

I have a 98 1.8T, K04'd w/borla exhaust, labree HFC, and some other stuff. I haven't driven the car much in the past 1-1.5 years but usually take it out every now and again. Unfortunately I didn't take it out very much if at all between late fall and early winter. The car ran fine before that but after sitting 2-3 months it has run like crap ever since. Any time I go WOT and more than like 7-10psi of boost the car seems to misfire or bog down. I have gotten a misfire code a few times, off the top of my head can't remember the exact code. If it starts acting up I usually just back off the throttle. A few times I have held it to see what happens and the car will get act up from 10psi-16psi or so then once it gets through that it seems fine. I can't figure out what it is.

When I started driving it again I did an oil change and changed the plugs out and put new BKR6Es in. Didn't help. I thought maybe it was the gas so I put some injector/fuel system cleaner in. Since then I have driven about 500 miles and no help of any kind. I am out of ideas on what it could possibly be. I feel like it could be a bunch of things (injectors, bad 710N, N75, boost/vac leak, coilpack, ICM) but I can't seem to figure it out.

Has anyone had a similar problem?

djwimbo
04-05-2008, 08:02 AM
What are your spark plugs gapped at?
You may be experiencing pre-ignition due to a carbon buildup, actually for that matter it could be a number of things.
Cyl #2 gets the most air into it just b/c of manifold design. Swap injectors from #2 to #3 and see if it moves.
At higher RPM and definitely under boost, you engine is ingesting a ton of air. That air is electrical resistance, even more so in a boosted application. If your spark plugs are gapped correctly, it is possible that your coil/s aren't producing enough to ignite the A/F charge.

mike-2ptzero
04-05-2008, 08:38 AM
i have, and the missfire at idle went away when i switched the #2 coil to the #1 cylinder
but it was still missfiring under load

i have not done a compression test, because the car is fine at idle and when driving out of boost, which i think almost rules out dropping a cylinder, correct ?


Well one of the cylinders could have a much lower compression, so its always best to do a compression check to rule that out.

trailertravis13
04-05-2008, 09:26 AM
What should BKR6E's be gapped at? I only have them in at the gap they came with. Should I buy a new set and gap them or can I just gap the set with 500 miles on them and be fine?

Whats the best treatment for the carbon buildup? Seafoam or something like that? Someone suggested using BG-44K a while back but I can't find it anywhere in a store.

auto_euroticaA4
04-05-2008, 02:37 PM
im also having this problem, ive replaced coil #2 and MAF. car doesnt misfire anymore but i still get a cel. p1128 rich mixture i believe.

trailertravis13
04-05-2008, 04:40 PM
im also having this problem, ive replaced coil #2 and MAF. car doesnt misfire anymore but i still get a cel. p1128 rich mixture i believe.

Hmmm...I had my MAF replaced already I believe less than 2 years ago, which since I drive the car so little is probably less than 10k miles.

Lazer Viking
04-05-2008, 07:57 PM
i'll do a compression test on monday
i;ve already switched the plugs from some shitty autolite plugs that were in there, to some bosch ones, gapped at .28
i'll have the codes scanned tommorow, and hope it tells me more then cyl 2 missfire

_audible_
04-06-2008, 07:26 AM
im also having this problem, ive replaced coil #2 and MAF. car doesnt misfire anymore but i still get a cel. p1128 rich mixture i believe.

P1128 is a lean condition.

auto_euroticaA4
04-06-2008, 02:09 PM
^^thanks, my scanner doesnt give me p11 codes

Lazer Viking
04-06-2008, 03:25 PM
got the codes, all are missfires except
p1602 power supply (B+) terminal 30 low voltage (wtf is this )

also go this bitch to miss at idle again and got the miss to follow the #2 coilpack, so i have new coils comming

a4mark1
04-09-2008, 03:44 PM
wow. im having this exact same problem.
trying to troubleshoot as much as possible.
Ill post if I get anywhere.

I feel SOL

a4mark1
04-09-2008, 03:53 PM
question for all of us:

Do you have an aftermarket air-filter or CAI?

How many people with this problem have software?
how many do not?

Just throwing some things out.

I have no software, with a carbonio and a testpipe.
I wonder if there is a common denominator to our problem

Lazer Viking
04-09-2008, 06:25 PM
giac chip, stock intake, stock exhaust, forge 004

mark_2328
04-09-2008, 07:26 PM
My car is doing the same thing. Only when I put the throttle down like 3/4 of the way, and get into boost it starts bogging down and misfiring. Haven't thrown any codes yet. New ICM less than a year ago, and new coil in #2 cylinder. I'm going to do a boost/vac leak test tomorrow to see what that shows. Other than that, i'm stumped.

a4mark1
04-09-2008, 07:53 PM
My car is doing the same thing. Only when I put the throttle down like 3/4 of the way, and get into boost it starts bogging down and misfiring. Haven't thrown any codes yet. New ICM less than a year ago, and new coil in #2 cylinder. I'm going to do a boost/vac leak test tomorrow to see what that shows. Other than that, i'm stumped.


wtf, everyone is having the same problem....

I'm bout to bite the bullet and let a professional find out what is really wrong..

Lazer Viking
04-09-2008, 07:57 PM
you probably should, and then let us know [up]

UN-PIMP-Z-A4
04-09-2008, 08:12 PM
last time my car was misfiring was because of a leak from the turbo to the tp.
tighten the bolts and the problem went away

mark_2328
04-09-2008, 08:59 PM
Did that make it smell like sweet gas in/around the car while driving? I might have an exhaust leak also. I'm thinking about bringing it to the stealership to check it out, I'm getting frustrated.

a4mark1
04-11-2008, 07:22 AM
Did that make it smell like sweet gas in/around the car while driving? I might have an exhaust leak also. I'm thinking about bringing it to the stealership to check it out, I'm getting frustrated.

Do you have a testpipe and if so was it installed recently?

mark_2328
04-11-2008, 08:13 AM
No test pipe. Unfortunately.

whoace
04-11-2008, 01:30 PM
Sweet smell is normally coolant leak

mark_2328
04-11-2008, 01:53 PM
Don't think its a coolant leak. Not losing any..

a4mark1
04-14-2008, 11:09 AM
No test pipe. Unfortunately.

mine began to have a sweet gas smell after my test pipe was installed, so I guess no help there.

UN-PIMP-Z-A4
04-14-2008, 02:59 PM
i have a testpipe but its a naseau enducing smell...
Aint shit sweet about it... LOL!
once the bolts were tightened up the misfires went away.

a4mark1
04-15-2008, 04:14 PM
huh that might be my problem...
lol yes very nausiating, but it does indeed have a distinct sweet smell to it ;)

a4mark1
04-15-2008, 11:10 PM
un-pimp,
when it was misfiring/stuttering, did your CEL come on?


i have a testpipe but its a naseau enducing smell...
Aint shit sweet about it... LOL!
once the bolts were tightened up the misfires went away.