MTFCA Forum

Today I did what I wanted to do for a very long time- I installed a 12 volt fuel shutoff valve. I connected everything up and decided to connect the power to the bottom of the 1926 coil box. It works, but I realized that that now I am switching between the Battery/Magneto. My concern is that the magneto could burn out the solenoid at higher RPM or fail/turn off at lower RPM.

What are your suggestions on how to connect up a fuel shutoff valve?

Matt

Without the valve, there is no chance of the solenoid burning out or the engine cutting out at low revs. If that is the worry, just throw the thing away. I wonder why it was necessary in the first place.

Allan from down under.

I agree with Allen, best fool proof solution is to remove the electric fuel shut-off valve.
Some people that do not want to crawl under the car to turn on or off the fuel valve add a second valve at the carb, not me, but some people.

It is a DC device, so should not work on the AC from the magneto. It would need it's own power supply from the battery. On the first go around with my Chevrolet over head, I used a VW carb that had one. I was running a distributor so was no problem wiring it into the ignition switch. You are going to have to wire up a stand alone switch that feeds from the DC side only.

Thanks for the advice.

I added the electronic fuel shutoff because sometimes the float sticks and gas floods down. I want it as a part of the key switch to avoid the case of turn off the fuel at every stop.

Is there any good way of using the key switch to run accessories from the battery like you do on a modern car ?

Matt

the only way I see to run it off of the switch is to use a low current relay (or you could go direct, but I wouldn't) and only run on battery.

I have to say, though that your solution to putting in an electric valve for a leaking carb is like Boeing placing cushions along their flight route to minimize crashes instead of go to Root Cause. I personally have a hand valve at the carb on all my T's because once, after 5 years, one leaked and I felt that a gravity feed system posed a risk for unmonitored off-site (or other) storage. It's easy. I agree that valves are good, but why not fix the problem? Leaking carbs can be fixed, and if they leak more than rarely, your car's performance will suffer significantly. FWIW.

would this work?

An electronic cutoff to solve a sticking needle and seat is weird. As Scott says, just fix the problem at the root, and fit a tap at the carb if you must have insurance.

Allan from down under.

The AC from the mag will NOT trigger the solenoid unless you have an AC solenoid to trigger your gas shut off. If you try to run a DC 12V (or worse, 6V) solenoid off the AC output of the mag, you will at best be gifted with a pile of smoking slag... the mag will put out up to 36 VAC...

IF you want to put a DC fuel solenoid shutoff on your car (and in 30+ years of T ownership I cannot figure why someone would do this) it needs to be on a separete fused DC link off a DC source. Running AC though it will not only not work, but heat that thing up (flashing on and off) to the gasoline combustion point.

We did a fuel pump and solenoid on an early 23 Lincoln... we had 2 fuses and a circuit breaker in line of that, and it STILL worried us. I would recommend a mechanical and physical shutoff... because you're not talking 2010 technology (nor even a '70's vehicle) but something that, if you're not willing to realize it's nature, will come back to bite you.

Matt, Try mounting a Model A fuel shutoff inside your 26 touring firewall, at least it will not fail in the off mode at a bad time.

Matt, If this fuel shut off is for your 1926 touring with the cowl tank and you do not want to open the hood every time, then you could use a Model A fuel shut off mounted on the inside passenger side of the firewall. Plum the fuel line over to the firewall, mount the shut off inside firewall with in and out fuel flow fittings in holes you make in the firewall. Keep the holes as small as possible so if you ever want to go back stock they would weld up easy after the tank is out. It is not power or automatic but at least it will not fail in off mode on a tour requiring you to remove it to drive, you may forget to turn it on but will soon figure it outand nd turn it on. it happens to Model A drivers.

.

O

How about an oil shutoff valve for the leaking oil?

Something like this would take a lot less plumbing then the Model A valve:
https://www.ebay.com/c/23011818009

Now that I finally realize this is a '26 with a fuel shut off built into the sediment bulb 18" away from the carb. I don't even recommending a shut off at the carb. Open the hood and turn it off. It's an antique car. If it's a burden, then I'm guessing that the front end isn't getting oiled, floorboards are not coming out to grease the ujoint and driveshaft bushing, steering bushing isn't being greased, and the steering gearcase isn't being serviced regularly either. It's an antique car.

The mere fact that there is 12V available in the car tells me that bandaids have already been applied instead of repairs, and honestly an electric fuel shut off is a bandaid, too. I don't say this to be critical, but to say that problem solving on this car is not directed at the causes but the symptoms, which will never be satisfactory in the end.

Matt. I think the electric fuel cutoff is a good idea. and have thought about adding one Myself. and since most of the T houses sell them there must be a market. I always turn the fuel off after a drive with the valve on side of the carb on both My open express and the 26 touring which also has a valve on the gas tank sediment bowl. I have had a carb float stick on the express and it will put a lot of gas on the ground in a short time. and the 26 with the vertical tank would be worse. just run valve off 12 volts. install a small toggle switch on the front of the driver seat base or put it in the dash. Your car may already have a doner hole or two in the dash from prior projects. mine did it also serves as a hidden kill switch. and if You are concerned about the electric valve failing connect it in parallel with manual cut off. should help cut down on hood latch wear which after a hundred years is pretty worn anyway. A under hood inspection is still a mandate on a regular basics. running Your T out of gas empting the carb fuel bowl can cause the valve to stick in the muck they sell for gas these days even in a good carb. AX Me how I know. Yes I have had the floorboards out of My car didn't take long with a sawzall. (Funny) ? Good Luck.