Engine running ruff after setting 78 L82
Thread Starter
Burning Brakes
Joined: Jul 2017
Posts: 1,114
Likes: 149
From: Frisco TX
From what I understand if it was the coil it would be ok cold then start failing when the engine gets hot. That's not happening.
If the ignition module fails you can't start the car. The car still starts normally.
1967 Pedal Car Champion
Joined: Mar 2020
Posts: 9,053
Likes: 4,194
From: US-PNW
Certainly could be. But there is only 5000 miles on the engine since the rebuilt.
From what I understand if it was the coil it would be ok cold then start failing when the engine gets hot. That's not happening.
If the ignition module fails you can't start the car. The car still starts normally.
From what I understand if it was the coil it would be ok cold then start failing when the engine gets hot. That's not happening.
If the ignition module fails you can't start the car. The car still starts normally.
A failing ignition module can behave perfectly fine until it gets hot -- it's really just a coil of a different design. You could test this by running the car until it fails and then using a can of Dust-Off (upside down), spray the module for a few seconds, which will quickly cool it. Reassemble and see how it behaves.
Thread Starter
Burning Brakes
Joined: Jul 2017
Posts: 1,114
Likes: 149
From: Frisco TX
For electronic components, I don't think miles are as important as age.
A failing ignition module can behave perfectly fine until it gets hot -- it's really just a coil of a different design. You could test this by running the car until it fails and then using a can of Dust-Off (upside down), spray the module for a few seconds, which will quickly cool it. Reassemble and see how it behaves.
A failing ignition module can behave perfectly fine until it gets hot -- it's really just a coil of a different design. You could test this by running the car until it fails and then using a can of Dust-Off (upside down), spray the module for a few seconds, which will quickly cool it. Reassemble and see how it behaves.
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,810
From: Cool Northern Michigan
Len,
The distributor Spring Bushing affects every single volt in the entire Ignition system.
Every single sparkplug firing goes through that bushing. Every single spark at thousand per minute, go through that bushing.
The bushing rubs on the rotor, correct? Or I should say the rotor rubs on the bushing.
So, what I am getting at is, the high resistance of the old gnarly bushing is restricting the voltage to the plugs. Instead of each plug receiving 50,000 volts, perhaps there is only 10,000.
Car runs like crap w/o a good, clean, blue, spark
Anyway, new dizzy is 25 yrs old? H-m-m-m-m-m-
When does it become "Not new?
The distributor Spring Bushing affects every single volt in the entire Ignition system.
Every single sparkplug firing goes through that bushing. Every single spark at thousand per minute, go through that bushing.
The bushing rubs on the rotor, correct? Or I should say the rotor rubs on the bushing.
So, what I am getting at is, the high resistance of the old gnarly bushing is restricting the voltage to the plugs. Instead of each plug receiving 50,000 volts, perhaps there is only 10,000.
Car runs like crap w/o a good, clean, blue, spark
Anyway, new dizzy is 25 yrs old? H-m-m-m-m-m-
When does it become "Not new?
Last edited by HeadsU.P.; Nov 2, 2024 at 07:35 PM.
Thread Starter
Burning Brakes
Joined: Jul 2017
Posts: 1,114
Likes: 149
From: Frisco TX
Len,
The distributor Spring Bushing affects every single volt in the entire Ignition system.
Every single sparkplug firing goes through that bushing. Every single spark at thousand per minute, go through that bushing.
The bushing rubs on the rotor, correct? Or I should say the rotor rubs on the bushing.
So, what I am getting at is, the high resistance of the old gnarly bushing is restricting the voltage to the plugs. Instead of each plug receiving 50,000 volts, perhaps there is only 10,000.
Car runs like crap w/o a good, clean, blue, spark
Anyway, new dizzy is 25 yrs old? H-m-m-m-m-m-
When does it become "Not new?
The distributor Spring Bushing affects every single volt in the entire Ignition system.
Every single sparkplug firing goes through that bushing. Every single spark at thousand per minute, go through that bushing.
The bushing rubs on the rotor, correct? Or I should say the rotor rubs on the bushing.
So, what I am getting at is, the high resistance of the old gnarly bushing is restricting the voltage to the plugs. Instead of each plug receiving 50,000 volts, perhaps there is only 10,000.
Car runs like crap w/o a good, clean, blue, spark
Anyway, new dizzy is 25 yrs old? H-m-m-m-m-m-
When does it become "Not new?
I checked all of my plugs with thee inductive timing light and all are firing.
That doesn't describe what you said about the voltage drop.
Which still could be the problem.
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,810
From: Cool Northern Michigan
I know of not one timing light capable of indicating that you do or do not have full voltage at the plugwire.
Its just a flash of light, strobe. But how many volts?
That rotor is arcing badly. Its arcing because of the bushing.
Pull it out and replace it. Obviuosly with new rotor also.
I bet you a chili dog, fries and a chocolate shake, your IGN issues will go away.
Its just a flash of light, strobe. But how many volts?
That rotor is arcing badly. Its arcing because of the bushing.
Pull it out and replace it. Obviuosly with new rotor also.
I bet you a chili dog, fries and a chocolate shake, your IGN issues will go away.
Melting Slicks
Joined: Jun 2014
Posts: 2,226
Likes: 497
From: NJ
If I understand what you saying is that the car should be running very badly. But this is not that severe. Like just 1 cyclinder is missing.
I checked all of my plugs with thee inductive timing light and all are firing.
That doesn't describe what you said about the voltage drop.
Which still could be the problem.
I checked all of my plugs with thee inductive timing light and all are firing.
That doesn't describe what you said about the voltage drop.
Which still could be the problem.
Thread Starter
Burning Brakes
Joined: Jul 2017
Posts: 1,114
Likes: 149
From: Frisco TX
I know of not one timing light capable of indicating that you do or do not have full voltage at the plugwire.
Its just a flash of light, strobe. But how many volts?
That rotor is arcing badly. Its arcing because of the bushing.
Pull it out and replace it. Obviuosly with new rotor also.
I bet you a chili dog, fries and a chocolate shake, your IGN issues will go away.
Its just a flash of light, strobe. But how many volts?
That rotor is arcing badly. Its arcing because of the bushing.
Pull it out and replace it. Obviuosly with new rotor also.
I bet you a chili dog, fries and a chocolate shake, your IGN issues will go away.
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Thread Starter
Burning Brakes
Joined: Jul 2017
Posts: 1,114
Likes: 149
From: Frisco TX
Burning Brakes
Joined: Aug 2011
Posts: 830
Likes: 288
25 years and 5,000 miles. Doesn't sound like it is driven much.
Car runs not as bad when first started then gets worse as it warms up? Gets worse as the choke goes off and the engine gets less fuel?
While the issue might be distributor related it would seem to me to be more carb related. All it takes is a little varnish in the wrong spot and you have troubles.
After tuning up the distributor, it might be time for a carb rebuild or at least cleaning. If that gas treatment sits too long it will start to build up on the jets.
Just something else to look into.
Car runs not as bad when first started then gets worse as it warms up? Gets worse as the choke goes off and the engine gets less fuel?
While the issue might be distributor related it would seem to me to be more carb related. All it takes is a little varnish in the wrong spot and you have troubles.
After tuning up the distributor, it might be time for a carb rebuild or at least cleaning. If that gas treatment sits too long it will start to build up on the jets.
Just something else to look into.
Thread Starter
Burning Brakes
Joined: Jul 2017
Posts: 1,114
Likes: 149
From: Frisco TX
25 years and 5,000 miles. Doesn't sound like it is driven much.
Car runs not as bad when first started then gets worse as it warms up? Gets worse as the choke goes off and the engine gets less fuel?
While the issue might be distributor related it would seem to me to be more carb related. All it takes is a little varnish in the wrong spot and you have troubles.
After tuning up the distributor, it might be time for a carb rebuild or at least cleaning. If that gas treatment sits too long it will start to build up on the jets.
Just something else to look into.
Car runs not as bad when first started then gets worse as it warms up? Gets worse as the choke goes off and the engine gets less fuel?
While the issue might be distributor related it would seem to me to be more carb related. All it takes is a little varnish in the wrong spot and you have troubles.
After tuning up the distributor, it might be time for a carb rebuild or at least cleaning. If that gas treatment sits too long it will start to build up on the jets.
Just something else to look into.
I didn't know about gas treatment cashing varnish. When I was checking for spark I started the engine 8 times with no problem.
The roughness is the same when the car is 1st started or when is has been driven for 30 minutes or so.
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,810
From: Cool Northern Michigan
Let's get back to basics.
Let's get back to post # 35 photos.
Thanks to my lap-tops ability, I was able to zoom in on your rotor Len.
Let's see. What two words would describe the condition of that rotor? Let me see. Let me see.
Oh ya. Holy crap. That thing is burnt and has an arcing mark where the spring bushing rubs.
I am not saying you need a new distributor. In fact, I think the cap itself can be cleaned of the mysterious splatter marks inside. Terminals look ok too.
However, change the rotor and bushing.
Glancing at Summits rotors, they have an el-cheapo, black one, for $5.99. (Likely has a one-week warranty)
They also have a red MSD quality unit for $27. (hint-hint)
They also have a Low Resistance MSD Spring Bushing for less than $20.
P.N. MSD 8412
You have three little phillip screws on the coil dust cover.
You have four bolts under that holding the coil in.
Under that is a rubber insulator and the bushing. Which appears in the photo as carbon tracked.
Very easy replacements.
Let's get back to post # 35 photos.
Thanks to my lap-tops ability, I was able to zoom in on your rotor Len.
Let's see. What two words would describe the condition of that rotor? Let me see. Let me see.
Oh ya. Holy crap. That thing is burnt and has an arcing mark where the spring bushing rubs.
I am not saying you need a new distributor. In fact, I think the cap itself can be cleaned of the mysterious splatter marks inside. Terminals look ok too.
However, change the rotor and bushing.
Glancing at Summits rotors, they have an el-cheapo, black one, for $5.99. (Likely has a one-week warranty)
They also have a red MSD quality unit for $27. (hint-hint)
They also have a Low Resistance MSD Spring Bushing for less than $20.
P.N. MSD 8412
You have three little phillip screws on the coil dust cover.
You have four bolts under that holding the coil in.
Under that is a rubber insulator and the bushing. Which appears in the photo as carbon tracked.
Very easy replacements.
Thread Starter
Burning Brakes
Joined: Jul 2017
Posts: 1,114
Likes: 149
From: Frisco TX
Let's get back to basics.
Let's get back to post # 35 photos.
Thanks to my lap-tops ability, I was able to zoom in on your rotor Len.
Let's see. What two words would describe the condition of that rotor? Let me see. Let me see.
Oh ya. Holy crap. That thing is burnt and has an arcing mark where the spring bushing rubs.
I am not saying you need a new distributor. In fact, I think the cap itself can be cleaned of the mysterious splatter marks inside. Terminals look ok too.
However, change the rotor and bushing.
Glancing at Summits rotors, they have an el-cheapo, black one, for $5.99. (Likely has a one-week warranty)
They also have a red MSD quality unit for $27. (hint-hint)
They also have a Low Resistance MSD Spring Bushing for less than $20.
P.N. MSD 8412
You have three little phillip screws on the coil dust cover.
You have four bolts under that holding the coil in.
Under that is a rubber insulator and the bushing. Which appears in the photo as carbon tracked.
Very easy replacements.
Let's get back to post # 35 photos.
Thanks to my lap-tops ability, I was able to zoom in on your rotor Len.
Let's see. What two words would describe the condition of that rotor? Let me see. Let me see.
Oh ya. Holy crap. That thing is burnt and has an arcing mark where the spring bushing rubs.
I am not saying you need a new distributor. In fact, I think the cap itself can be cleaned of the mysterious splatter marks inside. Terminals look ok too.
However, change the rotor and bushing.
Glancing at Summits rotors, they have an el-cheapo, black one, for $5.99. (Likely has a one-week warranty)
They also have a red MSD quality unit for $27. (hint-hint)
They also have a Low Resistance MSD Spring Bushing for less than $20.
P.N. MSD 8412
You have three little phillip screws on the coil dust cover.
You have four bolts under that holding the coil in.
Under that is a rubber insulator and the bushing. Which appears in the photo as carbon tracked.
Very easy replacements.
Thread Starter
Burning Brakes
Joined: Jul 2017
Posts: 1,114
Likes: 149
From: Frisco TX
Thanks everyone for all of you ideas/support.
I just got a call from my mechanic. He said it was a bad spark plug in #4. They changed it and the engine is back to normal.
Not sure what makes a plug go bad but this one did.
I just got a call from my mechanic. He said it was a bad spark plug in #4. They changed it and the engine is back to normal.
Not sure what makes a plug go bad but this one did.
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,810
From: Cool Northern Michigan
If he didn't swap-out the Cap & Rotor, you have gained very little.
Both of those parts are shot. No other way to describe it, just plain shot.
Spring Bushing under the coil is bad too.
Rotor is burned at both ends, both contact places and the cap has questionable terminals.
Plus, a very mysterious spray pattern internally.
Both of those parts are shot. No other way to describe it, just plain shot.
Spring Bushing under the coil is bad too.
Rotor is burned at both ends, both contact places and the cap has questionable terminals.
Plus, a very mysterious spray pattern internally.
1967 Pedal Car Champion
Joined: Mar 2020
Posts: 9,053
Likes: 4,194
From: US-PNW
Plugs can go bad in a couple of ways: they can have a cracked porcelain insulator that causes the spark to go to the engine block rather than the tip to ignite the fuel; they can get loaded up with debris that inhibits a good, consistent spark; the electrode can erode away; or they can get damaged on installation so that the gap is way too small. I'm sure there are other things but that's what came to mind.
I agree, for the inexpensive cost of a rotor and cap (~$50 combined), now is the time to change them. Shouldn't take more than 10 minutes for your mechanic, maybe 20 for you (you must keep the plug wires in the proper order on the cap).
I agree, for the inexpensive cost of a rotor and cap (~$50 combined), now is the time to change them. Shouldn't take more than 10 minutes for your mechanic, maybe 20 for you (you must keep the plug wires in the proper order on the cap).
Thread Starter
Burning Brakes
Joined: Jul 2017
Posts: 1,114
Likes: 149
From: Frisco TX
Plugs can go bad in a couple of ways: they can have a cracked porcelain insulator that causes the spark to go to the engine block rather than the tip to ignite the fuel; they can get loaded up with debris that inhibits a good, consistent spark; the electrode can erode away; or they can get damaged on installation so that the gap is way too small. I'm sure there are other things but that's what came to mind.
I agree, for the inexpensive cost of a rotor and cap (~$50 combined), now is the time to change them. Shouldn't take more than 10 minutes for your mechanic, maybe 20 for you (you must keep the plug wires in the proper order on the cap).
I agree, for the inexpensive cost of a rotor and cap (~$50 combined), now is the time to change them. Shouldn't take more than 10 minutes for your mechanic, maybe 20 for you (you must keep the plug wires in the proper order on the cap).
I am curious how a plug just stops working. Hopefully he saved the spark plug and it shows something.
Le Mans Master
Joined: Jun 2019
Posts: 7,649
Likes: 2,466
From: Indiana
can you comment n what were the plugs?
Thread Starter
Burning Brakes
Joined: Jul 2017
Posts: 1,114
Likes: 149
From: Frisco TX
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,810
From: Cool Northern Michigan
Some of us had trouble with a bad batch of NGKs.
There were also some fake NGKs going around.
But I had 3 out of a dozen fail.
Most of those NGK issues were resolved a while back.
There were also some fake NGKs going around.
But I had 3 out of a dozen fail.
Most of those NGK issues were resolved a while back.