# VR6 Turbo misfires coilpack, maf...?



## [email protected] (Mar 16, 2004)

**EDIT* Car is now running much better after doing the "jbweld fix" to the coilpack* 
Car is a 98' GTi VR6 Turbo
Specs on the setup:
ATP turbo kit
C2 motorsports ODB2 chip, maf, 440cc injs.
Precision SC61 turbo
JE Pistons 8.5:1
Currently the car has bkr6e vpower copper plugs, I've had 7s and it does the same thing. Tried the Iridium NGK 7s and they were very bad. Plugs have been gapped anywhere from .024-.020 and no matter what, this issue still exists.
It seems to have gotten steadily worse over the past few months. What's weird is that once it gets to a decent operating temp, but before its been running for a while you can make a low boost run with a blinking cel, but you can't really feel the misfires. Then if you try to make a pull through another gear it misfires like crazy.
I think its a combination of the coilpack and old stock plug wires. 
My plan is to get the autotech wires and a new coilpack from parts4vws, unless anybody knows where to get one for under $250.
One day I tried unplugging the MAF, but that just made it fall on its face and drive like crap.
Let me know what you guys think. Probably won't be getting the coilpack/wires for a few weeks, because I just got done spending a bunch on money on replacing 3rd gear and getting some wiring issues sorted out. Its not absolutely necessary right now anyway, because the car runs great when I'm not in boost. (under ~3000rpms)



_Modified by [email protected] at 11:15 AM 10-10-2005_


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## jsnVR6 (Feb 5, 2001)

*Re: VR6 Turbo misfires coilpack, maf...? ([email protected])*

I know my car missfired when the plug wires were not fully seated. I would definatly change the plug wires first. I got new wires and have not had a single missfire since http://****************.com/smile/emthup.gif


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## [email protected]vr6dynos.com (Mar 16, 2004)

*Re: VR6 Turbo misfires coilpack, maf...? (JsnVR6Corrado)*

Alright, sounds good. I guess I'll order some wires soon then and see if that helps.
Now which ones should I get. 
Autotech 10.4mm- $140








or
Magnecor KV85 8.5mm - $120
I'll probably go with the autotech, but if anyone has any advice on the subject I would appreciate it.


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## Zupek (May 10, 2000)

*Re: VR6 Turbo misfires coilpack, maf...? ([email protected])*

been there done that....
Simple explaination is a boost leak. Mine was a hairline crack in the exhaust manifold. It was also a bad knock sensor. But I tried it ALL. Different plugs, different wires, race fuel, etc. No matter what you do, its a waste of money because if you fix the wrong thing, the problem comes back right away.
Best thing to do. STANDALONE....
MAF's suck


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## [email protected] (Mar 16, 2004)

*Re: VR6 Turbo misfires coilpack, maf...? (fatfreevw)*

Yeah, sometimes I feel like it is the knock sensor kicking in, but I've had it on a wideband and it does it with anything from 11:1 to 12.5:1 a/f ratios. 
If I had the money to do standalone right now I would, but I think I want to go with DTA and its a decent chunk of change.
Whats the best way to check for boost leaks? The misfires actually seem to be a lot worse as soon as the wastegate opens up.


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## Zupek (May 10, 2000)

*Re: VR6 Turbo misfires coilpack, maf...? ([email protected])*

pressure test...which is pretty much closing the system off @ the end and putting the air into the engine without an exit...
if you can get pressure with a smoke tester, your set


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## [email protected] (Mar 16, 2004)

*Re: VR6 Turbo misfires coilpack, maf...? (fatfreevw)*

smoke tester? Can anyone tell me or show me where I can find more info on pressure testing? Now that I think about it, this could be one of my problems.


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## Zupek (May 10, 2000)

*Re: VR6 Turbo misfires coilpack, maf...? ([email protected])*

a fog/smoke testing machine is normal @ a lot of ma & pa shops. It just releases air with a smoke into the the throttle body and you look for it seep out of the system somewhere. But it doesnt have much pressure. 
Or you can do the water test w/ air pressure...which is pretty much cover your car in soapy water and pressurize the system. If it bubbles in certain areas, its a possible boost leak.


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## patatron (Aug 10, 2003)

*Re: VR6 Turbo misfires coilpack, maf...? ([email protected])*

Old plug wires are a huge cause of misfires on forced induction cars. I would guess this is all of your problem. http://****************.com/smile/emthup.gif


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## Zupek (May 10, 2000)

*Re: VR6 Turbo misfires coilpack, maf...? (patatron)*

yeah it would be good to replace them anyways....go through the basic things...alot of car guys have a tendancy to look for the most complicated thing when it usually the easiest...so by all means try what you want


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## [email protected] (Mar 16, 2004)

*Re: VR6 Turbo misfires coilpack, maf...? (fatfreevw)*

Definitely going with the plug wires first, then after that, a coilpack probably. Is the 1.8t MAF the same as mine?


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## mechsoldier (Aug 14, 2004)

*Re: VR6 Turbo misfires coilpack, maf...? (fatfreevw)*

You can test the wires with a ohm meter, they should have over 1k ohms of resistance and the longer the wire the more resistance it should have (the exact specs should be in the bently) also you can try spraying the wires with water, the water will make the spark take the path of least resistance and it'll misfire if the insulation is degraded.
Do yourself a favor and check the coil's resistance and compare to specs too....don't just throw parts and money at the thing 


_Modified by mechsoldier at 7:46 AM 10-1-2005_


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## Evolution Marine (Sep 18, 2003)

*Re: VR6 Turbo misfires coilpack, maf...? (mechsoldier)*

You can test the coil pak by spraying water on it at night with no lights around the car and reving the motor from the engine compartment. If the coil pak is bad it will arc.







- Bob


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## DieGTi (Jun 19, 2001)

*Re: VR6 Turbo misfires coilpack, maf...? (Evolution Marine)*

Just did this on my car before I drove across the US. The connector on my front bank knock sensor was corroded from the engine/wiring being out of the car for a year. A spritz of wd40 on the connector and it's all good. What codes are you getting with the blinking CEL? The computer doesn't read from the knock sensors until the engine coolant is up to 140 iirc.


_Modified by DieGTi at 7:41 PM 10-2-2005_


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## [email protected] (Mar 16, 2004)

*Re: VR6 Turbo misfires coilpack, maf...? (DieGTi)*


_Quote, originally posted by *DieGTi* »_Just did this on my car before I drove across the US. The connector on my front bank knock sensor was corroded from the engine/wiring being out of the car for a year. A spritz of wd40 on the connector and it's all good. What codes are you getting with the blinking CEL? The computer doesn't read from the knock sensors until the engine coolant is up to 140 iirc.

Actually, for some reason one day my coolant temp gauge on the dash stopped working. On the vagcom i just get misfire codes.


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## MiamiVr6T (Jul 24, 2004)

*Re: VR6 Turbo misfires coilpack, maf...? ([email protected])*

coilpack had solved all my misfire problems.. waiting to put in new wires i had purchased when i eventually change the plugs


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## [email protected] (Mar 16, 2004)

*Re: VR6 Turbo misfires coilpack, maf...? (MiamiVr6T)*


_Quote, originally posted by *MiamiVr6T* »_coilpack had solved all my misfire problems.. waiting to put in new wires i had purchased when i eventually change the plugs









What is your turbo setup? How bad were your misfires?


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## [email protected] (Mar 16, 2004)

*Re: VR6 Turbo misfires coilpack, maf...? ([email protected])*

Oh, and what should my fuel pressure be at idle? I should be running 3 bar with the c2 stuff i think, so 44psi with the fpr vac line removed at idle?
I'm asking because I think I'm running more like 60psi.


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## MiamiVr6T (Jul 24, 2004)

*Re: VR6 Turbo misfires coilpack, maf...? ([email protected])*

well on cold starts i can feel the car sputtering till it gets a good temp... and when i tried to boost the car it wouldn't let me pass 4lbs like if it had a revlimiter.. it would sputter like crazy and would have to let off.. off boost wasn't that bad.. i mean if you haven't changed the wires or coilpack before then that'll prolly be my guess


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## [email protected] (Mar 16, 2004)

*Re: VR6 Turbo misfires coilpack, maf...? ([email protected])*

I definitely think its coilpack/wires, but my fuel pressure also bothers me. I have an adjustable fpr and with the inline fuel pump turned on I get like 60psi of pressure, vac line removed.
If I pull the fuse for the pump the pressure drops to like 34psi. Right now I have the fuse pulled on the inline and the pressure set at 44psi and it runs smoother, gets better mpg, but doesn't run good in boost still.


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## a4chris (Jan 27, 2000)

*Re: VR6 Turbo misfires coilpack, maf...? ([email protected])*

Eric, last time your car was here the coil pack post were hanging by a moment cause you filter is pressed up against it, change coil pack first then wires or both at the same time. every mis-fire will be gone.
Chris Green


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## veedub11 (Mar 10, 2002)

*Re: VR6 Turbo misfires coilpack, maf...? (BALLIN-AUDI)*

Magnecor > Autotech


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## [email protected] (Mar 16, 2004)

*Re: VR6 Turbo misfires coilpack, maf...? (BALLIN-AUDI)*


_Quote, originally posted by *BALLIN-AUDI* »_Eric, last time your car was here the coil pack post were hanging by a moment cause you filter is pressed up against it, change coil pack first then wires or both at the same time. every mis-fire will be gone. 

Thanks, but do you have any idea why my fuel pressure goes up so much with my inline pump running. It kills my gas mileage and makes the car run much worse off boost. Clogged return line?


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## DieGTi (Jun 19, 2001)

*Re: VR6 Turbo misfires coilpack, maf...? ([email protected])*

Sounds like it could be a bad FPR. Try priming the pump without firing the injectors to see what type of pressure the pump can build up passing through the inline pump(with the fuse removed) and to see if it might be a FPR issue.


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## a4chris (Jan 27, 2000)

*Re: VR6 Turbo misfires coilpack, maf...? ([email protected])*


_Quote, originally posted by *[email protected]* »_
Thanks, but do you have any idea why my fuel pressure goes up so much with my inline pump running. It kills my gas mileage and makes the car run much worse off boost. Clogged return line?

sounds like a bad FPR, or a weak intank pump.
Chris Green


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## Zupek (May 10, 2000)

*Re: VR6 Turbo misfires coilpack, maf...? (DieGTi)*


_Quote, originally posted by *DieGTi* »_Sounds like it could be a bad FPR. Try priming the pump without firing the injectors to see what type of pressure the pump can build up passing through the inline pump(with the fuse removed) and to see if it might be a FPR issue. 

i think to prime the pump all you have to do is turn the key to the On position without starting the car. But i could be wrong...


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## DieGTi (Jun 19, 2001)

*Re: VR6 Turbo misfires coilpack, maf...? (fatfreevw)*

With OBD2 you'll have to jump the relay to prime the pump. OBD1 will prime by key.


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## [email protected] (Mar 16, 2004)

*Re: VR6 Turbo misfires coilpack, maf...? (BALLIN-AUDI)*


_Quote, originally posted by *BALLIN-AUDI* »_Eric, last time your car was here the coil pack post were hanging by a moment cause you filter is pressed up against it, change coil pack first then wires or both at the same time. every mis-fire will be gone.
Chris Green 


Chris was right. I took the coilpack off and JB welded it on top to cover any cracks and help support the plug posts. Car runs amazing now. Still get flashing cel when in boost for a while.


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## Boostedvrt69 (Jul 19, 2015)

Zupek said:


> been there done that....
> Simple explaination is a boost leak. Mine was a hairline crack in the exhaust manifold. It was also a bad knock sensor. But I tried it ALL. Different plugs, different wires, race fuel, etc. No matter what you do, its a waste of money because if you fix the wrong thing, the problem comes back right away.
> Best thing to do. STANDALONE....
> MAF's suck


So what did u do to find that?? I just replaced the whole ignition set up on my vrt and its running like garbage, very bad misfire under boost like a 100hp is gone


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