Intermittent miss

[Car15]

I have a miss that just comes and goes on a 1967 barracuda.
The only thing I can see wrong is the perotrnix 3 distributor cap doesn't lock down tight like most other caps it wiggled around on the distributor. Does anyone else's pertronix do that?

 

[TrailBeast]

I have a miss that just comes and goes on a 1967 barracuda.
The only thing I can see wrong is the perotrnix 3 distributor cap doesn't lock down tight like most other caps it wiggled around on the distributor. Does anyone else's pertronix do that?

Bend the retainer clips so it does fit tight, but the intermittent miss is probably something else.
WAY too many possible answers to that one.

 

[Tooljunkie]

The gods need more to go on.
Engine, mods,whether its hot or cold ,particular gear or rpm when it happens. During accel or decel.

 

[Car15]

The gods need more to go on.
Engine, mods,whether its hot or cold ,particular gear or rpm when it happens. During accel or decel.

340 during acceleration under load usually around 3 4 grand hot or cold no mods really just the distributor ,flamethrower coil and a holley

 

[Car15]

Bend the retainer clips so it does fit tight, but the intermittent miss is probably something else.
WAY too many possible answers to that one.

No clips on the pertronix like the mopars have this is a L shape rod you push down and turn into position

 

[Car15]

Idk ive had bad voltage regulators act like that too

 

[TrailBeast]

340 during acceleration under load usually around 3 4 grand hot or cold no mods really just the distributor ,flamethrower coil and a holley

I would start with the ignition system and timing first and if everything looked good move on to carburation.
Since you have a Holly, you know about power valves?
If not there are some guys here that can help with that, because I'm not a Holley pro.

No clips on the pertronix like the mopars have this is a L shape rod you push down and turn into position

I hate those things even when they work right.
They do normally work fine as long as the spring is capable and the cap fits though.

 

[KitCarlson]

Get some long leads for your voltmeter and read the voltage at coil plus to ground as problem occurs.

Take the cap off, look at terminals inside to read tracking pattern. Caps typically have an index, perhaps the cap is 180 off.

 

[Car15]

I would start with the ignition system and timing first and if everything looked good move on to carburation.
Since you have a Holly, you know about power valves?
If not there are some guys here that can help with that, because I'm not a Holley pro.




I hate those things even when they work right.
They do normally work fine as long as the spring is capable and the cap fits though.

Get some long leads for your voltmeter and read the voltage at coil plus to ground as problem occurs.

Take the cap off, look at terminals inside to read tracking pattern. Caps typically have an index, perhaps the cap is 180 off.

I got the cap indexed correctly it's just doesn't sit on there tight, and only does it going down the road .

 

[Car15]

The voltage regulator was very hot was the other thing I noticed today

 

[KitCarlson]

The voltage regulator was very hot was the other thing I noticed today

That is a sign of trouble. What is the voltage at blue wire going to coil +. Was the ballast resistor byoassed, as it should be?
Please report on voltage, that gives us something to work with. The coil charge time is inversely proportional to voltage. Low voltage fails to properly charge the coil at higher RPMs.

 

[Car15]

That is a sign of trouble. What is the voltage at blue wire going to coil +. Was the ballast resistor byoassed, as it should be?
Please report on voltage, that gives us something to work with. The coil charge time is inversely proportional to voltage. Low voltage fails to properly charge the coil at higher RPMs.

Ballast is bypassed I'll get back with on the coil . Key on position or engine running?

 

[KitCarlson]

Yes, engine running, per post #8, what happens to voltage when missing happens...

 

[Car15]

Coil voltage

Yes, engine running, per post #8, what happens to voltage when missing happens...

Jumped around mostly stayed at 18v and down to seven here and there.
Run position it's at 12v
The battery is at 13 v

 

[KitCarlson]

Coil voltage

Jumped around mostly stayed at 18v and down to seven here and there.
Run position it's at 12v
The battery is at 13 v

Sounds like wiring issues, things like bad connections at bulkhead connector, possibly regulator, or grounds. With engine running, should see 13.8V might deviate a few tenths, some temperature related.

Both 18V and 7V very bad, not something you want to drive like that...may damage electronics, wiring, battery or electrical fire.

If regulator is mechanical, upgrade to electronic. Also review the numerous prior posts, by 67Dart273 bout trouble shooting wiring and charging system.

 

[Car15]

Sounds like wiring issues, things like bad connections at bulkhead connector, possibly regulator, or grounds. With engine running, should see 13.8V might deviate a few tenths, some temperature related.

Both 18V and 7V very bad, not something you want to drive like that...may damage electronics, wiring, battery or electrical fire.

If regulator is mechanical, upgrade to electronic. Also review the numerous prior posts, by 67Dart273 bout trouble shooting wiring and charging system.

I seen the mad upgrades if that what your referring to but as far as connections go I had 13 v on both sides of the bulkhead where the alternator wire goes in and the dark blue wire comes out .

 

[KitCarlson]

It makes a difference, if electrical load is on the system. Voltage drop is current times resistance, no current, no drop. In post #14, there was a 1V difference. And 18V to 7V, that is crazy, and major problem. What type of meter are you using? Seems like readings are to nearest volt.
I am not saying mad upgrades is necessary, just good connections. 67Dart273 has many posts on measuring voltage drops, and trouble shooting.

 

[Car15]

It makes a difference, if electrical load is on the system. Voltage drop is current times resistance, no current, no drop. In post #14, there was a 1V difference. And 18V to 7V, that is crazy, and major problem. What type of meter are you using? Seems like readings are to nearest volt.
I am not saying mad upgrades is necessary, just good connections. 67Dart273 has many posts on measuring voltage drops, and trouble shooting.

18 volts on the coil positive is crazy high or the difference in spikes and lows?
I'm going to do the mad upgrades but I want to fix this issue first .
I just have a cheap meter from like Wal-Mart or something

 

[KitCarlson]

I am trying to help, but have you read my post #15? The regulator system if working correctly, regulates IGN circuit voltage to 13.8V at about 68F, it will go a few 0.1V higher when colder and lower when hot.
A battery voltage over 14.5V is too much, and suggests voltage drop problems. The field of alternator is controlled by the regulator, the regulator senses IGN, but with voltage drop the battery voltage will run higher, by the voltage drop between IGN, and battery. If 18V, was measured at IGN, that may suggest the regulator is stuck, and may be providing full field, however drops to 7V, suggests poor connections. This means there is likely more than one problem.

 

[Car15]

I am trying to help, but have you read my post #15? The regulator system if working correctly, regulates IGN circuit voltage to 13.8V at about 68F, it will go a few 0.1V higher when colder and lower when hot.
A battery voltage over 14.5V is too much, and suggests voltage drop problems. The field of alternator is controlled by the regulator, the regulator senses IGN, but with voltage drop the battery voltage will run higher, by the voltage drop between IGN, and battery. If 18V, was measured at IGN, that may suggest the regulator is stuck, and may be providing full field, however drops to 7V, suggests poor connections. This means there is likely more than one problem.

Yeah I read them I needed to read them slowly lol! you started talking about voltage drops when i had had such high numbers the light bulb just came on lol