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View Full Version : Misfiring continues. Your help is wanted



A4Rob
04-11-2007, 01:35 PM
My car continues to misfire under boost. I have switched the plugs AGAIN, back to the NGK BRK7E, from the 6E's (gapped at .028). I just replaced the ICM also. Now, I just ordered 4 new coil packs and a fuel filter. Does anyone have more ideas to fix the problem?

Could it be a dirty throttle body?

Thanks for any help in advance

clconversion
04-11-2007, 01:48 PM
Hey Rob I just took out my BKR7E's on my T28 sustem because of misfiring and put in the Bosch F5DP0R's and now it runs great

A4Rob
04-11-2007, 01:58 PM
Are those the same plugs that 034 sells?

pac1085
04-11-2007, 02:02 PM
034 does sell them, they are the $15/each platinum ones. They are ok but some people have issues with them. They fouled out REALLY easy for me. I hear good things about those 3-prong bosch plugs that 034 carries as well.

nizmosx
04-11-2007, 04:33 PM
Hey Rob I just took out my BKR7E's on my T28 sustem because of misfiring and put in the Bosch F5DP0R's and now it runs great

i had this issue as well. its your gapping on the plugs.

also you could have possibly got away with just changing the boots on the coil packs and not the entire units.

turboquattro068
04-11-2007, 04:40 PM
YEAH DUD EI HAD THE SAME PROBLEM, STILL GETTING MISFIRES, it may be the plugs, i changed out my coilpacks and icm, i only get misfires mainly when i just start the car, and also, a small number..very unoticeable when shes warmed up?! could be same problem, but yeah it sucks!



LOL, I love my run-on sentences!

turboquattro068
04-11-2007, 04:42 PM
I have an extra throttle body thats in excellent shape, extra icm, and two extra coils, let me know if u need something rob

offroader1006
04-11-2007, 05:55 PM
i had the same problem under load, random cylinder misfires, it was the plug gap, i had it about .004" too much. regapped and no problems since.

Poopie
04-11-2007, 06:37 PM
believe it or not my misfires were clutch related. If your clutch is slipping and you have an aggressive tune, the load readings will be way off and the fuel map will be wrong leading to misfires and timing pull.

A4Rob
04-11-2007, 07:50 PM
Well it is NOT my gap. I have a very fine tool that measures gap and I have re-gapped them twice now. It is a very tight .028.

I actually might be interested in the throttle body if my new coils and plugs do not work.

mikeyvuitton
04-11-2007, 07:53 PM
probably a bad coil pack, if a spark plug swap dosnt fix it.

Poopie
04-11-2007, 07:54 PM
run some logs of your throttle body. I think its block 3. Log that block and block 20. then log 3 and 31 to see what we are working with.

Matt@JHM
04-11-2007, 07:56 PM
Well it is NOT my gap. I have a very fine tool that measures gap and I have re-gapped them twice now. It is a very tight .028.

I actually might be interested in the throttle body if my new coils and plugs do not work.

If you are running a lot of boost, you need a tighter gap. From what I understand more pressure makes it harder for the spark to jump the gap.

Try to re-gap them a little smaller and feel the results.

I know someone who runs a .021 gap - although it's an s4 pushing 22-25psi.

Poopie
04-11-2007, 08:03 PM
i know not everyones car is the same....but there really isn't a need to go that low.

A4Rob
04-11-2007, 08:03 PM
I understand that the boost can "blow out" the spark, but I have been running 23-25 psi for over 3 years now. I have always gapped at .028.

This monday I am swapping out all 4 coil packs, Bosch tri thingy plugs, and replacing the fuel pump. we'll see what happens

Poopie
04-11-2007, 08:04 PM
fuel pump is a good part to upgrade anyways. Is it the stock pump?

A4Rob
04-11-2007, 08:08 PM
Yes stock pump. I am getting the Bosch 044 soon to support my 75/lb injectors

ice cream man
04-11-2007, 08:08 PM
could be a boost leak , have you ever vagged you car?

A4Rob
04-11-2007, 11:04 PM
It is not a boost leak. I have had my A4 for 4 years, 3 of which were big turbo. I know what a normal boost leak feels like. I am misfiring like a bitch. It's never been this bad. Normal misfires I have cured with new plugs or N75, but this one is unlike anything I have felt. I just hope it is not pre-detonation.

Nukkah03
04-11-2007, 11:15 PM
man I had plenty of misfires, always end up being the coilpack boot. Ask jeremy he can vouch how many of those I went through. Check to see if there is any rips or tear on any of them. Good luck man!

Nebone
04-11-2007, 11:22 PM
VAG the car while driving, do readings on individual cylinders, narrow it down to which one. Most likely a bad coil or vacuum/boost leak.

clconversion
04-12-2007, 10:29 AM
does anyone know the part # for the Bosch plugs the 3 prong ones ?

offroader1006
04-12-2007, 12:34 PM
Well it is NOT my gap. I have a very fine tool that measures gap and I have re-gapped them twice now. It is a very tight .028.

I actually might be interested in the throttle body if my new coils and plugs do not work.

eh, mine was at .028 and that was the reason, with 20 psi, i put it down to .024 using the gap calculator on NGK's site.

alen
04-12-2007, 12:37 PM
This monday I am swapping out all 4 coil packs, Bosch tri thingy plugs, and replacing the fuel pump. we'll see what happens

Are you going to replace just the coil packs and see if that is the issue (then move on to the plugs if not), just to troubleshoot the cause of misfires?

I've been getting misfires lately ever since my dyno day. I run high boost with j31 and never really had problems with misfires. If I am WOTing I would get like 10-15 misfires in random cylinders...so I put in a fresh set of 6Es at 0.028" and same thing happened. However, in the past few days it has been running perfectly. I've been testing it out lately but then I would get a misfire or two...sometimes! I don't know if it's the coilpacks since all cylinders would misfire.

Do you have high carbon on your plugs?

A4Rob
04-12-2007, 12:41 PM
Yes lots of carbon

turboquattro068
04-12-2007, 12:44 PM
a4rob we are in the same exact ballpark man, ive replaced my icm, coils, and plugs, gapped them at .028, im going to check the plugs tomorrow see what they look like and not, when i first start the car if i dont let it warm up really good it misfires until it gets warm, misfires really badly! I'm going to change out my fuel pump soon, and maybe go with a 5bar fpr....... lets stay in touch and figure this out

A4Rob
04-12-2007, 12:49 PM
I will definitly keep you posted. Monday when my 034 box comes I plan to do all the replacing.

jaybquick@JHM
04-13-2007, 11:23 AM
I never get missfires and mine runs 21 to 25 p.s.i. You should NEVER get missfires.

The only time I get missfires is when I have too large of a gap on my spark plugs, usually when they get some mileage and get wider than .025. When I upped the boost to 25 p.s.i at the track I started getting missfires above 6000 rpm, I tightened the gap down to .023 and it went away. I have 115k on my stage 3+ car and NEVER had a bad coilpack, just plug gap issues and a coil boot once.

It is simple how the ignition systems work. Spark plugs missfire due to increased resistance in the combustion chamber. This higher resistance occurs in 3 ways. High boost, too large of a spark plug gap and the wrong fuel mixture, usually lean or a combination there of. YORU CAR HAS HIGHER BOOST THAN THE FACTORY IGNITION WAS DESIGNED FOR> therefore you must tighten the gap to a smaller number until the missfires go away. The factory coil packs just don't have the power to fight all that new found resistance. P.S. It will miss worse with high octane fuel due to it burning at a slower rate.

Oh yeah, I was an ASE master certified tech with his smog license for 5 years and raced all kinds of cars namely Mustangs for over 15. So I ain't blowing smoke up your butt.

YOU NEED TO REGAP YOUR PLUGS.

There are at least a dozen S4 owners who have fixed their problems by simply listening to me. Obviously I can't see your car in person, but I have been right about this 9 out of 10 times. Unfortunately a lot of people modify their cars with no basic concepts of how ignition systems work in relation to combustion chamber pressures and mixtures.

mike-2ptzero
04-13-2007, 11:48 AM
I never get missfires and mine runs 21 to 25 p.s.i. You should NEVER get missfires.

The only time I get missfires is when I have too large of a gap on my spark plugs, usually when they get some mileage and get wider than .025. When I upped the boost to 25 p.s.i at the track I started getting missfires above 6000 rpm, I tightened the gap down to .023 and it went away. I have 115k on my stage 3+ car and NEVER had a bad coilpack, just plug gap issues and a coil boot once.

It is simple how the ignition systems work. Spark plugs missfire due to increased resistance in the combustion chamber. This higher resistance occurs in 3 ways. High boost, too large of a spark plug gap and the wrong fuel mixture, usually lean or a combination there of. YORU CAR HAS HIGHER BOOST THAN THE FACTORY IGNITION WAS DESIGNED FOR> therefore you must tighten the gap to a smaller number until the missfires go away. The factory coil packs just don't have the power to fight all that new found resistance. P.S. It will miss worse with high octane fuel due to it burning at a slower rate.

Oh yeah, I was an ASE master certified tech with his smog license for 5 years and raced all kinds of cars namely Mustangs for over 15. So I ain't blowing smoke up your butt.

YOU NEED TO REGAP YOUR PLUGS.

There are at least a dozen S4 owners who have fixed their problems by simply listening to me. Obviously I can't see your car in person, but I have been right about this 9 out of 10 times. Unfortunately a lot of people modify their cars with no basic concepts of how ignition systems work in relation to combustion chamber pressures and mixtures.


You must be talking about blow out. I ran 24psi with normal plugs at .032 with no problem and am still running stock ATW coil packs while running 32psi boost with the bosch tri plugs which are F6DTC and can be bought at 034 and Eurocode. Rob is going 034 stand alone so will most likely be going waste spark anyway.



turboquattro068 - Why do you want to go with a 5bar fpr? That just makes things worse since you are already pushing the fuel pumps out of their PSI rating. The best thing to do is run larger injectors and 3 bar fpr. Fuel pumps dont have a good flow rating when running at 80psi, since 5bar is already 72.5psi that doesn't give you much room for boost on top of that and means you either have to run more injector pulse because of the drop off of flow from the fuel pump.

jaybquick@JHM
04-13-2007, 11:57 AM
You must be talking about blow out. I ran 24psi with normal plugs at .032 with no problem and am still running stock ATW coil packs while running 32psi boost with the bosch tri plugs which are F6DTC and can be bought at 034 and Eurocode. Rob is going 034 stand alone so will most likely be going waste spark anyway.



turboquattro068 - Why do you want to go with a 5bar fpr? That just makes things worse since you are already pushing the fuel pumps out of their PSI rating. The best thing to do is run larger injectors and 3 bar fpr. Fuel pumps dont have a good flow rating when running at 80psi, since 5bar is already 72.5psi that doesn't give you much room for boost on top of that and means you either have to run more injector pulse because of the drop off of flow from the fuel pump.

Yup blowout. What does the 034 setup do to the coilpacks to make them handle that boost at that gap.

The oem ecu is very sensitive to plug gap, well at leat for us S4 guys. I would imagine the same. I even have a wideband on my car and I hold an 11.5:1 AF all the way to redline. You were at the track with me once when I had to regap my plugs due to top end miss. Remember that?

mike-2ptzero
04-13-2007, 12:08 PM
Yup blowout. What does the 034 setup do to the coilpacks to make them handle that boost at that gap.

The oem ecu is very sensitive to plug gap, well at leat for us S4 guys. I would imagine the same. I even have a wideband on my car and I hold an 11.5:1 AF all the way to redline. You were at the track with me once when I had to regap my plugs due to top end miss. Remember that?



Well with the 034 IIc unit I have always ran the bosch tri plugs that they sell. I dont think the 034 unit does anything different to control the stock ATW coil packs but I guess I can always ask Javad or Nate. When I was running the singles it was back when I was running the stock ECU with custom GIAC tuning at 24psi.


Have you thought about running the Bosch tri plug? Nice thing about them is that you never have to gap them.

jaybquick@JHM
04-13-2007, 12:25 PM
Well with the 034 IIc unit I have always ran the bosch tri plugs that they sell. I dont think the 034 unit does anything different to control the stock ATW coil packs but I guess I can always ask Javad or Nate. When I was running the singles it was back when I was running the stock ECU with custom GIAC tuning at 24psi.


Have you thought about running the Bosch tri plug? Nice thing about them is that you never have to gap them.

I will have to try them next time I need plugs. I have the denso irridiums

turboquattro068
04-13-2007, 12:54 PM
im running decent size injectors to begin with, how do you increase your injector pulse?.......Im upgrading my fuel pump asap, what do you reccomend and whats the easiest to drop in!?

A4Rob
04-13-2007, 02:46 PM
im running decent size injectors to begin with, how do you increase your injector pulse?.......Im upgrading my fuel pump asap, what do you reccomend and whats the easiest to drop in!?


Bosch 044 unit is 10million times better than a Walboro 255.

Eurotuned_A4
04-13-2007, 02:53 PM
im thinking about getting the the bosch tri ones. i just cant stand the way the ngks i have used start so crappy in the cold. i never had an issue with the boschs

A4Rob
04-13-2007, 02:58 PM
Here is what I ordered:
4 Bosch tri plugs
New eBay ICM
4 Coilpacks
8 ft of vac hose
Fuel Filter
MAF wiring Harness (old one is kinda melted)


Hopefully this shit will get all sorted out so I can drive!

Oh yea, also I have some updates on my body work too :)

mike-2ptzero
04-13-2007, 03:05 PM
Bosch 044 unit is 10million times better than a Walboro 255.

Very much so, plus 034 sells the Bosch 044 as a drop in which is the setup I run in my car.


turboquattro068 - Tuner has to increase it when doing the tuning for the chip. The dbw guys can increase or decrease it but that is across the board. What size injectors are you running now and what FPR? If you are running a 4bar you could use a 3-6bar fpr and add a little fuel pressure at a time, then add the Bosch 044 pump which will help flow because it is the best flowing pump when runinng near 80psi.

turboquattro068
04-15-2007, 09:47 AM
right now im running a 4bar, I seem to be running a little lean. I also run the ngk colder plugs wich suck right now because the weather here is like 40 degrees, i have to let the car warm up or i get misfires from hell. Should i definitly upgrade my fuel pump? I'm thinkinng of ordering one today, and who is this 034 guy? Or is it a company?

mike-2ptzero
04-15-2007, 09:56 AM
right now im running a 4bar, I seem to be running a little lean. I also run the ngk colder plugs wich suck right now because the weather here is like 40 degrees, i have to let the car warm up or i get misfires from hell. Should i definitly upgrade my fuel pump? I'm thinkinng of ordering one today, and who is this 034 guy? Or is it a company?

Well upgrading the pump wont hurt that is for sure.

034 Motorsport

link to their fuel pump page on their site (http://www.034motorsport.com/index.php?cPath=24_78)

A4Rob
04-15-2007, 10:21 AM
Alright UPDATE!,

I vagged my car and got misfires in cylanders 1 and 3, MAF output too high, throttle body and N75.

I also noticed my MAF wires were pretty melted so I replaced those and swapped plugs over to the Bosch Platnum f5dpor. It ran good for about ten minutes then my car completely shut off. It felt like my Maf was shot... again, so I unplugged it and limped the car back home. I obviously need another new MAF element, so I will be picking that up this week. When the car WAS running good, it would occasionally "misfire" but the VAGcom wouldn't pick it up. I think this is telling me that my stock fuel filter IS clogged. So when my stuff comes I will be replacing all of it and updating this thread to tell you whats all going on. It's kinda like a BLOG. haha

turboquattro068
04-15-2007, 02:40 PM
dude sounds like you got a short to ground with your maf wires and the rest of em, happend to me before, check all your engine fuses, i cant remember wich ones but they say timing i think, if that fuse is blow thats your problem!!!

A4Rob
04-15-2007, 03:53 PM
dude sounds like you got a short to ground with your maf wires and the rest of em, happend to me before, check all your engine fuses, i cant remember wich ones but they say timing i think, if that fuse is blow thats your problem!!!

Good idea. Thanks for the advice

turboquattro068
04-15-2007, 04:50 PM
all that wiring is connect, mine melted together at one point in time, blew one of my fuses, i went through a new maf, icm, blah blah, then just poopped a new fuse in, haha, good luck

A4Rob
04-22-2007, 12:47 PM
UPDATE #3

Well I think I figured out my problem. When I was replacing my fuel filter, I noticed that one of the small "out" lines from the filter was kinked! After replacing the filter, I pulled the line out and it was pretty much broken! I ordered a new line from the dealership. I think that this will solve my fuel delivery problem.

http://img.photobucket.com/albums/v468/a4robm/IMG_1993.jpg


While the car is down for a few days, I replaced all 4 coil packs and switched to some of the Bosch Tri Plugs. Also, I installed the 034 stainless coil cover:p It looks pretty cool. With all this new stuff I think it is about time to go all out and put the 034 in soon. SO, SOMEONE PLEASE BUY MY T28 setup so I can make another purchase from 034
http://img.photobucket.com/albums/v468/a4robm/IMG_1997.jpg


Oh and here is the harness that Tab and BMthorn built for my MAF

http://img.photobucket.com/albums/v468/a4robm/IMG_1999.jpg

My project is NEVER ENDING

jaybquick@JHM
04-22-2007, 04:17 PM
The only thing that sucks about changing those ingnition components while it is down, is that if it is all better. You won't know for sure what it was. Since an ignition problem or lean condition will cause missfiring up in the rev range.

A4Jon1.8t
05-06-2007, 11:17 AM
How exactly do you spot this, cause I think I have the same problem. At first I thought it was my diverter valve but I pulled it and regreased/repacked it and it's still happening. It seems to hold boost "okay" taking off from a light under normal acceleration. But on the interstate, when I get on the gas a little, I'm getting an initial increase in boost then it drops off about a half second after it builds. If I stay on the gas it repeats over and over in rapid succession. Seems to only happen in the mid, to high rpm range.

A4Rob
05-06-2007, 11:59 AM
How exactly do you spot this, cause I think I have the same problem. At first I thought it was my diverter valve but I pulled it and regreased/repacked it and it's still happening. It seems to hold boost "okay" taking off from a light under normal acceleration. But on the interstate, when I get on the gas a little, I'm getting an initial increase in boost then it drops off about a half second after it builds. If I stay on the gas it repeats over and over in rapid succession. Seems to only happen in the mid, to high rpm range.


That is how mine started. Trust me, it will get so bad that you will not even be able to spool at all. My car is running perfect now after $300 worth of maintanance stuff. I would suggest exactly what I did:
eBay ICM
4 new coils
Bosch tri plugs
Fuel filter (check your stock "out" line for kinks)

A4Jon1.8t
05-06-2007, 01:14 PM
Thanks. I don't have the $$ for the ICM or the filter right now but a friend of mine is going to give me his old coils and plugs until I get paid. Thanks for the info.