Arcing Coil

[BlackBourbon]

I searched for a while but didnt come up with anything. 87 Burb TBI. I checked for any loose wires or connections and also checked all the resistance values on the coil with a manual and multimeter. For some reason I'm getting some nice blue spark between the band of the coil and the coilwire post while running. It sits there and idles fine, just arcs like crazy

 

[dyeager535]

I think they get cracks or something in them...I noticed my setup was doing it when I used an old coil, I believe I replaced it (can't recall if new or just another used one), and don't believe it does it anymore, but honestly never checked. Coil I don't believe ever actually caused problems.

If mileage and/or driveability aren't suffering, I don't think I'd worry about it...well, ok I would...I don't think it's right, but it's not harming anything if the truck runs as it should.

 

[BlackBourbon]

Yeah I guess I'll just slap a new coil on there and see if it fixes it. I've been goin through replacing sensors(MAP,O2,Ign. Module,etc) trying to figure out the running issues I've been having and now this haha. Next is to pull and clean the EGR valve.

I just wanted to start building the damn thing but don't want to start on that until it's up and running right. If I throw some lift, axles and tires at it right now it would just be a 6000lb yard ornament haha.

 

[trikstark5]

I had a similiar problem and just replaced the coil with one from MSD. Problem is all gone now.

 

[throttleissues]

If the center contact button in the dist cap is wasted, you can get the same thing due to increased resistance. You oghtta replace the coil wire too, cuz I'm sure it now has carbon tracks in it that will bring the problem back even on a new coil.

 

[4X4HIGH]

I think they get cracks or something in them...I noticed my setup was doing it when I used an old coil, I believe I replaced it (can't recall if new or just another used one), and don't believe it does it anymore, but honestly never checked. Coil I don't believe ever actually caused problems.

If mileage and/or driveability aren't suffering, I don't think I'd worry about it...well, ok I would...I don't think it's right, but it's not harming anything if the truck runs as it should.

Wow, now add a very small fuel leak at the TBI lines and you don't see a problem.

The coil should NEVER be arcing at anytime, anywhere EVER. He needs to replace the coil ASAP before he burns the truck to the ground if a leak does develop.

 

[dyeager535]

Maybe your guys coil is mounted close to fuel lines...mines nowhere near it, so no problem in my case.

Regardless, spark plug wires never arc? Exhaust isn't hot enough to ignite fuel? Don't think I've ever bought a used vehicle that didn't need plug wires.

But I do agree...additional ignition sources are not needed!

 

[BlackBourbon]

Wow, now add a very small fuel leak at the TBI lines and you don't see a problem.

The coil should NEVER be arcing at anytime, anywhere EVER. He needs to replace the coil ASAP before he burns the truck to the ground if a leak does develop.

Haha exactly what I was thinking. Just wanted to see if anything else could be the culprit before I bought a new coil.

 

[4X4HIGH]

TBI rigs have the coil mounted directly behind the fuel lines. Yes, other hot sources can start a fire but you're guaranteed a fire from fuel spraying onto an arcing coil.