Help with Electrical Gremlin

[Steve69]

Hey Guys

Ive took my mustang out a few times this year and noticed a electrical problem and Im looking for some areas I should be checking. Last year
I installed a new Holley Avenger Carb 570 and a Mallory Hyfire box and
a Msd Blaster. Im also running a Unilite distributor. I also made sure I
had 12volts of powere at run position going to the Hyfire box.

The problem Im having sometimes at idle the engine is shutting off like the
switch is being turned off. Go to restart and it fires right off again. Sometimes when Im cranking the engine over it wont fire until I bring back to the run position. It hasn't shut off when driving the car which is good thing. Any Sugestions on this. I was leaning towards ignition switch.

Thanks

 

[stangonline]

Hmm. Most ignition boxes have 2 wires - one that dges directly to the battery (must go to battery +, cant splice into another 12v) and one that goes to a KOEO 12v, which simply tells the box to turn on. If by chance you put both of these together and to a KOEO or KOER, you could have that problem.

 

[Steve69]

Yea your right. There was a fulltime power that connects to battery
and the other wire which is ingnition power on. I did double check the
wires and there wire correctly.

 

[Steve69]

What is Koeo and Koer?

 

[stangonline]

Yea your right. There was a fulltime power that connects to battery
and the other wire which is ingnition power on. I did double check the
wires and there wire correctly.

Ok, well the other thing to check is the amp draw. If its too high, the voltage could be dropping too low to power the ignition box. Also, just for testing, move the wire that is ignition power on directly the the battery, just to see if it fixes the problem - do not drive, or leave it like that.

 

[stangonline]

Been a long time, so I might have them screwed up - I intended them to mean key on engine off, and key on engine running.

 

[Steve69]

I also just added a 130amp 3G alternator and didn't think of the amps.
I have between 13 and 14 volts when engine is running. Not sure about
the amps.

 

[bnickel]

you may not have enough voltage to the coil. i had this problem when i had an external resistor on the car in conjunction with the factory resistor wire.