bad coil??

[gn84guy]

Hey everyone,
I've had my 84 gn for just under two years now and its been a lot of fun, but now its actin up on me... Whenever i try to go under WOT it stumbles and makes an almost backfiring noise??? It is also ideling real rough like its on about 4-5 of its six cyl...Would this be because of a bad coil, cause the spark is too weak and its getting blown out by the higher boost or could it be something else? Just wounderin if you guys could give me your two cents on what you think it could be?
Thanks
-Bert

 

[Jerryl]

Change anything lately?
Did you measure the coil?
New plugs?
Good plug wires?
Fuel pump replaced? What pressure?
What are your O2, MAF, BLM numbers?

 

[gn84guy]

When it first started happenin i changed the plugs, and put new wires on it, unfortunatly that didnt help it.... As far as numbers go i dont really now i just got some guages for it and havent gotten them into it yet, and im also in the market for a scan tool but dont have one yet. I am surely not an expert in any means when it comes to these cars. Like i said i got this car not too long ago and im learnin as i go with it...
Basically, i just wanted to know if there where any other parts on these cars other than the coil that could cause this to happen?
Thanks for the response.
-Bert

 

[83ttypecooled]

bad misfire

Hi,
Sounds like a good possibility for a bad coil. Carefully, pull one wire from each coil while running and check output. A good coil will zap your a--, so be careful. A bad coil section will barely cross the arc when you use a test light as a safety. Fuel could be an issue too. More info needed!

 

[Jerryl]

Pull the wires and check the coil accress the towers.
This is out of www.gnttype.org

Coil Tower Resistance
(measure front to back, on top) 11K - 13K ohms
(for each of the 3 towers)

http://www.gnttype.org/maint/quickref.html

 

[gn84guy]

Ok. I guess the first place i'll start with when i get home from college this weekend is testing the coil. Thanks for the imput! I have only been on this site a little while, and from reading previous threads i've learned a heck of a lot! It will be a very good site for when i start to tweak this car. My goal is 12.5 qtrs with it. Just so i can stuff the "cubes are better" talk my brother is givin me with his 72 chevelle back in his face. I just can't wait to see his face when i stomp him that first time, but from the sounds of it i got a little bit of work and of course money...ahead of me.
Thanks again
-Bert