Could this be reason of misfire/rough idle???

84GNv6

Member
Joined
Apr 29, 2009
Havent had my ttype very long but it does have a rough idle and a misfire. I have little to none mechanic knowledge. Could this be the reason? What wires are best for our cars and what spark plugs are recommended. Any help is appreciated. Thanx!

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Get the Kirban set. Around $50. They are grey like the factory wires, and cut to same length as factory. Just make sure to seat the wire to the plug. The plug boot slides on the wire and I was getting misfiring until properly seated them.
Plugs Autolite 23.
 
1. Looks to me like the module potting material is melted out, and running down the sides....Fatal.
2. When replacing the wires, plugs, use di-electric grease on all connections.
3. If you don't know the ins/outs of these cars, find someone that does, and learn from them. Your GN "experience" will have a much higher chance of being a success.
 
Pul that plug wire off with it running. If no change in rpm, idle, that could be it. Do it with each wire to isolate which cyl has the miss.
 
I wouldn't pull them off with it running, I never liked that technique.

But, pull them one at a time and look for rust/corrosion of the coil terminals. If there is any, then you can clean it but it will come back. You should just replace those wires. Kirbans, or BlackGN1 on the board here both make good wires.

Bob
 
use a test light with it running ground light to battery then us the pointed end push it throw the top of the spark plug that an easier way to test when done get some silicone put a lit coat on top of the plug wire to seal the hole let it dry.
 
i guess you've been shocked before so instead of saying i wouldn't do it that way either, till us what way would you do it
 
I don't have a way to test the spark with the engine running. But pulling the wire off the tower while running forces the spark to crossfire to the mounting bolt, which is not good for the longevity of the coil. Poking holes in the insulation is going to mess with the high voltage breakover capability of the wires. Using a test light on a circuit that has 30,000 volt spikes in it is a pretty rough way to test this anyway.

The stock ignition is a reasonable performer when in top condition. Just maintaining the parts is the first step. Corroded/rusty coil terminals is a symptom that the wires are in need of replacement, and perhaps the coil as well.

What the OP should do is remove the wires one at a time and clean and inspect them. But for a rough idle he also needs to look into vacuum leaks, BLM issues, injector issues, etc.

The RTV on that one wire means that there are probably other issues going on with them and replacing them is a good idea.

Bob
 
Thanx for the feedback guys...I will be replacing wires. Will update when I do. A chevy friend of mine recommended acdelco wires and acdelco platinum plugs. How do these work on our cars or should I just go kirban wires.
 
Thanx for the feedback guys...I will be replacing wires. Will update when I do. A chevy friend of mine recommended acdelco wires and acdelco platinum plugs. How do these work on our cars or should I just go kirban wires.
No on the plugs use only copper core regular plugs,wires are fine. Agian as stated get a friend that know these cars they are regular cars you will be better off and so will the car.
 
Where are you located? That will help getting you with someone that can really help.

OH....Come on......30,000 volts will "LEARN YA!":D Until you get hit with a spark a time or two, you just haven't lived yet.:p No it won't kill you, either. (unless you have a pace maker) but OH MAN!!!! does it feel good! Ever been hit by an MSD ignition??? That'll WAKE you up better than a Quad Espresso/ Red Bull from Starbucks!
 
Bob is giving you great advice: clean and replace and components that look nasty! If you still have issues, here are a couple of time tested tips the help you track down the cause of a miss:

To help you figure out your misfire, here are a couple of safe and effective ways to short out cylinders with the engine running:
1. With the IAC unplugged, Unplug one injector at a time and listen. This kills the fuel and the cylinder goes dead.
2. Install 6 1" pieces of vacuum hose between the coil tower and the wire boot. With a test light connected to ground, touch one piece of vacuum hose at a time. The vacuum hose is only mildly conductive and will not miss until you provide an easier path to ground (through the test light).

Any cylinder that does not drop rpm is your problem cylinder. If you run a compression check or leakdown test, start on these cylinders first.
 
You could also have someone mist water over the wires while you power brake it a little and put a load on the engine.
 
I use a temp gun , each cylinder exhaust should be the same. One real cold (fuel no spark or is it spark no fuel?)I forget.that's the dead one.I have never been shocked or burnt
 
Pull the wires one by one and test them with an OHM meter. There is a spec on what range they should be in. If you can't find the range, compare them to each other. This is step one. Your test results will determine where you go next.
 
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