My car has been running and starting poorly of late. The pattern has been that it starts great at first, but runs worse and worse and then dies and is really hard to start - backfires and generally runs poorly. This all started on the heels of installing a weber 38. As part of that process i was installing an electric fuel pump and was looking for a switched 12v power source. Checked the coil lead and only 6 v. That jumps to 7v when the car is running. The I terminal on the starter solenoid, which I believe feeds the coil, has 0 volts. Yes, 0. What gives? All leads welcome.
6 volts at coil??!! help
- Thread starter falcon fanatic
- Start date
A
Anonymous
Guest
Yes. 6 volts at the coil is normal. There is a resistor wire that runs from the ignition switch to the coil. The starter relay does not feed the coil, the igition switch does. That is also the only other place you will find a useable 12V Switched power source. I can recomend a auxillary fuse box. I can't remember who they are made by, but I will look it up. It will come from the batt, go to the box, and provide you with multiple switched and unswitched 12V sources. You could pigtail off the igition switch, but for anything other than switching to a 12V coil, I feel this would be too dangerous (cause an overload), and for an elec fuel pump, you need a dedicated power source with overload protection.
Bill
Bill
The "I" terminal on the starter relay feeds a full 12v to the coil when the starter is turning over. Then the voltage will drop to around 6v to the coil when it is running.
If your carb is flooding, adding an electric fuel pump may make things worse. If it helps, you'll probably need a fuel pressure regulator so the float is still capable of turning off the fuel at the same level.
When you add accessories to key switched voltage, use the keyed power to power up a relay coil and the relay wired to switch battery voltage to the accessory. That way you won't overload & ruin the ignition switch.
If your carb is flooding, adding an electric fuel pump may make things worse. If it helps, you'll probably need a fuel pressure regulator so the float is still capable of turning off the fuel at the same level.
When you add accessories to key switched voltage, use the keyed power to power up a relay coil and the relay wired to switch battery voltage to the accessory. That way you won't overload & ruin the ignition switch.
Am I crazy? I did the following:
Used the 6v lead to the coil to trigger a relay that feed a full 12v to both the coil and the pump. It works, but I'm worried that it's a kooky thing to do. Should i just leave the coil at 6v?
Used the 6v lead to the coil to trigger a relay that feed a full 12v to both the coil and the pump. It works, but I'm worried that it's a kooky thing to do. Should i just leave the coil at 6v?
Thats a darn fine question about leaving the coil at 6v. I thought that it was originally set that way so that the points would last longer?
I have done 2 Duraspark II upgrades and I did both by using the coil power wire to trigger a relay, but I also upgraded both with 12v coils.
Check out this unit from my '68,
it houses a 4 fuse block 25amp rated with 4 30 amp rated relays that each have 2 outputs and a GM module. I tucked it neatly behind the pass hood spring when I got done hooking everything up. I put a round end on a wire and plugged it into the original round female plug that went onto the coil. At the fuse block end I spliced, soldered, heat shrinked (heatshrank?) it all back together nicely. From this fuse box I have powered the electric choke, the 12v coil, the GM module and the remote power for the radio. That only uses 2 of the 4 relays (I like redundancy) And if I ever upgrade to electric fans or electric fuel pump I have extra connections.
And the best part, NO EXTRA HOLES needed to be drilled in my car, I made the bracket to use existing bolts/holes, same with the second one I did, which I still need to get pics of.
-ron
I have done 2 Duraspark II upgrades and I did both by using the coil power wire to trigger a relay, but I also upgraded both with 12v coils.
Check out this unit from my '68,
it houses a 4 fuse block 25amp rated with 4 30 amp rated relays that each have 2 outputs and a GM module. I tucked it neatly behind the pass hood spring when I got done hooking everything up. I put a round end on a wire and plugged it into the original round female plug that went onto the coil. At the fuse block end I spliced, soldered, heat shrinked (heatshrank?) it all back together nicely. From this fuse box I have powered the electric choke, the 12v coil, the GM module and the remote power for the radio. That only uses 2 of the 4 relays (I like redundancy) And if I ever upgrade to electric fans or electric fuel pump I have extra connections.
And the best part, NO EXTRA HOLES needed to be drilled in my car, I made the bracket to use existing bolts/holes, same with the second one I did, which I still need to get pics of.
-ron
Coupe, I really like that setup. I was lying in bed last night trying to figure out how to do something like that. My engine bay looks like spaghetti right now! Not to mention that the last time I went to start the car it went pfft and all electrical died. i just went to bed.
Falcon,
No. Originally I was using the mechanical pump and it was okay when cold, but wouldn't start when hot. A weber vendor suggested a phenolic spacer and converting to this carter pump that delivers 4.5 psi. When I asked about the regulator the "you don't need it. I set up all my webers like this." I have my doubts. I upgraded the idle jets because it was running too lean and I can't do the lean best idle adjustment now because it wont idle at all without the idle speed screw in, which nulifies the adjustment. This I was able to do with the mechanical pump. The more I fix the more I ruin!
Falcon,
No. Originally I was using the mechanical pump and it was okay when cold, but wouldn't start when hot. A weber vendor suggested a phenolic spacer and converting to this carter pump that delivers 4.5 psi. When I asked about the regulator the "you don't need it. I set up all my webers like this." I have my doubts. I upgraded the idle jets because it was running too lean and I can't do the lean best idle adjustment now because it wont idle at all without the idle speed screw in, which nulifies the adjustment. This I was able to do with the mechanical pump. The more I fix the more I ruin!
A
Anonymous
Guest
Okay,
Here is the link to the Aux Fuse Block/Circuit Isolator. It is very similar to what coupboy built for his car, only this has Circuit Breaker/Overload protection. Don't know if coupboy's has that, if so kudo's to coupboy. The units range al the way from 3 circuits to 12, and are rated for 30 amps, and are only about 50 bucks.
Click on the link below, and then choose Fuse Blocks from the frame on the left.
http://www.painlessperformance.com/catalogframe.htm
Bill
Here is the link to the Aux Fuse Block/Circuit Isolator. It is very similar to what coupboy built for his car, only this has Circuit Breaker/Overload protection. Don't know if coupboy's has that, if so kudo's to coupboy. The units range al the way from 3 circuits to 12, and are rated for 30 amps, and are only about 50 bucks.
Click on the link below, and then choose Fuse Blocks from the frame on the left.
http://www.painlessperformance.com/catalogframe.htm
Bill
