Normal Spark?

[4Cruizn]

Does this look like typical spark?  Trying to chase down a spark issue I think . . . 

[brads70]

I may have been around Chevy's too long but isen't it suposed to be sparking from the side of the termanal not the top?
Almost like the rotor isen't pushed down far enough?

[moparmaniac59]

It looks like a LOT of juice going thru that rotor. I can't say what's causing it, but it does (to me) look a bit excessive as far as the electrical arc marks. I hope you can find the cause. What else is it doing besides excessive arcing? 


                                                                      Matt B.

[4Cruizn]

What else is it doing besides excessive arcing? 

Once it warms up, it starts to miss.  Last time I drove it . . . missed BAD . . was a hot day.   

[moparmaniac59]

Last time I saw anything like that was on my 1970 Barracuda 383 motor. I had the same type excessive burn/arc marks (in my distributor cap) & misfire like you're having. As it was explained to me that somehow oil vapors from the crankcase was leaking up thru the distributor shaft into the cap and would actually burn everytime the distibutor fires causing the normal spark to be amplified by the buring oil vapors and causing pitting and eventually misfire. I don't know if that was true, but sounded plausable. I installed a new distributor and no more problems. I guess I could have rebuilt the old distributor. I'm not sure if this is what's going on for your car Dave, I just thought I'd throw that out there as it just occurred to me. Hope you can get it fixed! 

                                                                         Matt B.

[4Cruizn]

Last time I saw anything like that was on my 1970 Barracuda 383 motor. I had the same type excessive burn/arc marks (in my distributor cap) & misfire like you're having. As it was explained to me that somehow oil vapors from the crankcase was leaking up thru the distributor shaft into the cap and would actually burn everytime the distibutor fires causing the normal spark to be amplified by the buring oil vapors and causing pitting and eventually misfire. I don't know if that was true, but sounded plausable. I installed a new distributor and no more problems. I guess I could have rebuilt the old distributor. I'm not sure if this is what's going on for your car Dave, I just thought I'd throw that out there as it just occurred to me. Hope you can get it fixed!       Matt B.

So first what you are saying is this is not normal . . . . oil vapors??       Wow I never would of guessed that!    The damn thing is pretty much new . . . is it just a gasket?  O-ring maybe?     Kind of waiting for CP to jump in . . .    need opinions . . .

[AARuFAST]

Brad70 is correct.  The spark should be off the side. The tip of the rotor should send the spark to the plug pins.
You either have the wrong rotor or cap. The ROTOR is making contact on the edge which makes the rotor look burnt.
Or the rotor is not pushed all the way on the shaft.  Seeing the coil carbon ball looks like it was not pushed full on shaft.

[Chryco Psycho]

Sorry , been working 12+ hrs a day for weeks , lack of sleep & !/2 brain dead right now 
 I have been trying to figure out the electrical / heat issue with your car for a while , not coming up with good answers so far
 The center terminal in the cap looks chipped off , usually the spark will jump to the sides but the spark is getting to the terminal so I do not see that as the issue . the corrosion on the tip of the rotor looks normal to me , I often just files them to clean them up , the larger the gap the more power the coil will have to build to jump it so unless the gap is so large the coil is too weak to jump it ? The spark should fail under load not idle though . How do the wires test for resistance , how do the plugs look ? At least you have a vented cap .

[ShelbyDogg]

When I test my spark ECUs I get a least a 1/2" spark from the center coil wire to ground.  Look at your ignition system and stop studying your cap so much. I don't have problems with rotors and yours should work fine.

[AARuFAST]

Pic shows how rotor should look inside of cap.

Pic shows how it is wrong inside of your cap.  It looks like you have the wrong rotor

Do u still have the original rotor to match it.

Get a new correct rotor and cap since the carbon ball is damaged.....

[4Cruizn]

I should say this is for the convertible . . . Stock 440 . . . . Going to replace and compare the new with the old today.   Will see what happens. 

[ShelbyDogg]

Only thing I ever check in my distributors is:
1. The reluctor to pickup gap.
2. make sure I can't move the shaft side to side to close the reluctor to pickup gap, (worn bushing)
3. that the reluctor is put down on the pin in the correct direction of rotation, (correct orientation point the rotor correctly according to the 8 points on it.   You checked this, right? Look for the markings on the reluctor, down by the pin slot. 2 ways to install it.

I don't think I've changed a rotor in forever.

[4Cruizn]

Only thing I ever check in my distributors is:
1. The reluctor to pickup gap.
2. make sure I can't move the shaft side to side to close the reluctor to pickup gap, (worn bushing)
3. that the reluctor is put down on the pin in the correct direction of rotation, (correct orientation point the rotor correctly according to the 8 points on it.   You checked this, right? Look for the markings on the reluctor, down by the pin slot. 2 ways to install it.

I did look that over and it appears to be correct.  I checked the gap and that is good as well.  Chryco set it up and I have to assume it is correct.  So I pulled out plug 1 and 3 and even with my limited experience reading spark plugs, I was happy with what I saw.  Need to go for a ride and see if the new cap and rotor helped at all. 

[brads70]

Hi Dave!     I just happened to be installing my distributor into the new 451 last night so I snapped a few pictures to show you what mine looked like after 3 years of driving. Notice were the "spark contact?" is . Picture explains it better? 

[dodj]

I like aarufast's theory. Rotor just too high? Or wrong rotor? His suggestions make logical sense to me.