# misfire on cylinder 3



## VT 4-motion (Jun 14, 2009)

I have a code of cylinder 3 misfiring. Plugs, wires and ignition coil are good. I can't find any vacume leaks. I checked the voltage of all four o2 sensors, all seem to be ok. Mass air flow sensor has been cleaned. Intake air temp sensor and water temp sensor resistance were within specs. I did disconnect the battery a while ago, could this cause the problem I am having? Any other ideas would be greatly appreciated!


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## Slimjimmn (Apr 8, 2006)

*Re: misfire on cylinder 3 (VT 4-motion)*

did you REPLACE the plugs and wires or did you just look at them and say yeah, they look ok. ?


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## VT 4-motion (Jun 14, 2009)

The plugs are new ngk oem. Haynes manual said 4000-6000 ohms on the wires, they all read 5000. I was going to order new ones tomorrow anyway. I put a new coil in yesterday but had no improvement. thanks for responding.


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## VT 4-motion (Jun 14, 2009)

I also changed the fuel filter. The plugs were changed before the valve cover gaskets. A few of the plugs and wire boots had alot of oil on them. Can the oil ruin the plugs? It was about a month before I changed the gaskets.


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## dutchGTIdriver (Jan 10, 2009)

i had same problem.. its most likely your injectors..
i had misfire in #1.. i have new coil pack, wires and plugs.. so i knew it wasnt one of those creating the issue. i took out my injectors.. got them all ultrasonically cleaned at a shop and then ended up having to buy 1 new one as it was toast.


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## dutchGTIdriver (Jan 10, 2009)

Good DYI.. it lead me through with no problems!
REPLACING FUEL INJECTORS ON A MKIV 12V VR6
by: VgRt6


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## VT 4-motion (Jun 14, 2009)

Thanks for the info, it looks like that will be my next move.


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## Slimjimmn (Apr 8, 2006)

*Re: (VT 4-motion)*

you have a v6 not a vr6, totally different engines. I have never seen an injector on a 30v v6 go bad or heard of one go bad. If the spark plug tubes have oil in them arround the spark plug enough to cover the end of the plug wire than you need to get the oil out of there and replace the wires. (just pull the plug and spray brake clean in there and then put the plug back in and run the engine to clean out the oil)


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## VT 4-motion (Jun 14, 2009)

The new spark plug wires will be in tomorrow morning. I cleaned the oil out last week, but I have a feeling it did some damage like you said. If I drive it in tiptronic mode with a light foot and keep rpm's between 2000 and 3000 there is almost no misfire until I come to a stop. I'm hoping the wires help. Thanks again.


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## spitpilot (Feb 14, 2000)

*Re: (VT 4-motion)*

Did you flex the wires while connected to your ohmmeter? Sometimes you can get good resistance reading with wire just laying there, but during flexing it can cause an issue..also check the spring clips that make contact to plugs..I had misire issue that came and went...seemed only at certain rpms...tore my hair out checking and changing parts that could have caused the problem...finally during one last check B4 taking it in for a running scope test...I happened to notice black marks on one plug electrode..seems the spring contact had "lost tension" and would cause poor contact..only when that particular wire hit resonance frequency at certain engine rpms..devious problems are the ones that come and go!


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## VT 4-motion (Jun 14, 2009)

Spitpilot, you are exactly right! I changed the wires right before I read your reply, and no more misfires. I should have replaced the old wires to start with. I guess I seriously over-thought this one. Thanks for everybody's help, problem solved. 
NGK plug wires were $140 from NAPA they ordered them overnight with no charge. They are actually Made In USA. http://****************.com/smile/emthup.gif 


_Modified by VT 4-motion at 3:30 PM 6-16-2009_


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