The Ford Barn

Seattledavid · 04-28-2023, 07:25 PM

I installed a Stromberg E-fire on my 1947 Ford Super Deluxe that is 6 volt positive ground. I used the correct one and the plug wires from Stromberg also and the 1.5 ohm coil they suggested. I finally got the car to start after I charged the battery. It is running rough at higher speed. The voltage coming from the ignition to the white wire is over 6 volts but if I check the voltage on the negative side of the coil it is only about 1/2 a volt. Shouldn’t it be 6 volts?? Is that causing the rough running. Do I need to advance the spark also??

Dave

tubman · 04-28-2023, 07:45 PM

This is the second time in two days that this has come up. Please read this thread in it's entirety, paying special attention to my post, #15 : https://www.fordbarn.com/forum/showthread.php?t=325962.

JayChicago · 04-28-2023, 07:48 PM

Do you have your coil wired backwards? Your car is positive ground. You wrote: "voltage on the negative side of the coil it is only about 1/2 a volt." But that side of the coil is the ground, positive. Input, the hot side, is negative. I have read a car will run with coil in backwards, but not well.

Also, 1/2 volt reading on the ground side of the coil sounds right to me. It is going directly to ground thru the distributor, so shouldn't be holding much voltage there.

Seattledavid · 04-28-2023, 08:01 PM

I have the + side wired to ground and the negative side of the coil wired to the black wire from the e- fire so that should be correct. Shouldn’t I have 6 volts on the negative side or am I confused.

JayChicago · 04-28-2023, 08:14 PM

OK. E-Fire. Sorry. I'm not familiar with that, so I will shut up.

deuce lover · 04-29-2023, 06:22 AM

Sponsored Links (Register now to hide all advertisements)

Suggest you contact Stromberg in UK by email since they make the unit.
https://www.google.com/url?sa=t&rct=...7lD0ZTo9sp53KU

BlueSpark · 04-29-2023, 10:25 AM

Are you measuring the - side with the engine running? The distributor has a transistor that drives the coil instead of points. If the transistor is "off" there should be no voltage across the coil. If the transistor is "on" there should be close to 6V across the coil. I dont know if these distributors will keep the coil energized if the engine is not running, I hope not. Put your meter across the coil primary and turn the engine over slowly. You should see the voltage change from 6V to 0V and back over and over. A measurement with the engine running is meaningless unless you use an oscilloscope. If I get a chance today I will see if these efires will stay "on" if the engine is not running.

aussie merc · 04-30-2023, 01:31 AM

also please be aware that the E fires are electronic and are very dependant on smooth voltage [no micro spikes] and have a minimum voltage requirement when cranking to work so battery and wiring condition is paramount . Mallory actually have hidden in their line up two items that should be fitted with their distributors and when you read the fine print they say that 1 or both MUST be used with generators and are desirable with alternators .Back to E fires i would wire them directly off the battery [not the solenoid ] via a relay as the battery will act as a condenser and absorb the majority of the micro spikes and ensure smooth constant voltage . As for the battery biggest one that will fit and ensure that the starter etc are in good working order to maintain best possible voltage when cranking

04-28-2023, 07:45 PM	#2
tubman Senior Member Join Date: Dec 2013 Location: Minnesota, Florida Keys Posts: 10,402	Re: Stromberg E-fire This is the second time in two days that this has come up. Please read this thread in it's entirety, paying special attention to my post, #15 : https://www.fordbarn.com/forum/showthread.php?t=325962.

04-28-2023, 07:48 PM	#3
JayChicago Senior Member Join Date: Jan 2019 Location: Chicago Posts: 747	Re: Stromberg E-fire Do you have your coil wired backwards? Your car is positive ground. You wrote: "voltage on the negative side of the coil it is only about 1/2 a volt." But that side of the coil is the ground, positive. Input, the hot side, is negative. I have read a car will run with coil in backwards, but not well. Also, 1/2 volt reading on the ground side of the coil sounds right to me. It is going directly to ground thru the distributor, so shouldn't be holding much voltage there. Last edited by JayChicago; 04-28-2023 at 08:07 PM.

04-28-2023, 08:01 PM	#4
Seattledavid Junior Member Join Date: Apr 2020 Posts: 29	Re: Stromberg E-fire I have the + side wired to ground and the negative side of the coil wired to the black wire from the e- fire so that should be correct. Shouldn’t I have 6 volts on the negative side or am I confused.

04-28-2023, 08:14 PM	#5
JayChicago Senior Member Join Date: Jan 2019 Location: Chicago Posts: 747	Re: Stromberg E-fire OK. E-Fire. Sorry. I'm not familiar with that, so I will shut up.

04-29-2023, 06:22 AM	#6
deuce lover Senior Member Join Date: May 2010 Location: Southern France Posts: 5,326	Re: Stromberg E-fire Sponsored Links (Register now to hide all advertisements) Suggest you contact Stromberg in UK by email since they make the unit. https://www.google.com/url?sa=t&rct=...7lD0ZTo9sp53KU

04-28-2023, 07:25 PM	#1
Seattledavid Junior Member Join Date: Apr 2020 Posts: 29	Stromberg E-fire I installed a Stromberg E-fire on my 1947 Ford Super Deluxe that is 6 volt positive ground. I used the correct one and the plug wires from Stromberg also and the 1.5 ohm coil they suggested. I finally got the car to start after I charged the battery. It is running rough at higher speed. The voltage coming from the ignition to the white wire is over 6 volts but if I check the voltage on the negative side of the coil it is only about 1/2 a volt. Shouldn’t it be 6 volts?? Is that causing the rough running. Do I need to advance the spark also?? Dave

04-29-2023, 10:25 AM	#7
BlueSpark Member Join Date: Feb 2023 Location: San Jose CA Posts: 61	Re: Stromberg E-fire Are you measuring the - side with the engine running? The distributor has a transistor that drives the coil instead of points. If the transistor is "off" there should be no voltage across the coil. If the transistor is "on" there should be close to 6V across the coil. I dont know if these distributors will keep the coil energized if the engine is not running, I hope not. Put your meter across the coil primary and turn the engine over slowly. You should see the voltage change from 6V to 0V and back over and over. A measurement with the engine running is meaningless unless you use an oscilloscope. If I get a chance today I will see if these efires will stay "on" if the engine is not running.

04-30-2023, 01:31 AM	#8
aussie merc Senior Member Join Date: Sep 2016 Location: sydney australia Posts: 1,038	Re: Stromberg E-fire also please be aware that the E fires are electronic and are very dependant on smooth voltage [no micro spikes] and have a minimum voltage requirement when cranking to work so battery and wiring condition is paramount . Mallory actually have hidden in their line up two items that should be fitted with their distributors and when you read the fine print they say that 1 or both MUST be used with generators and are desirable with alternators .Back to E fires i would wire them directly off the battery [not the solenoid ] via a relay as the battery will act as a condenser and absorb the majority of the micro spikes and ensure smooth constant voltage . As for the battery biggest one that will fit and ensure that the starter etc are in good working order to maintain best possible voltage when cranking