Just disable the starter and the distributor power lead, that would be enough
to detour any numb nut trying to steal the car, it would take a while to
find these changes and reverse them. If some one want your car bad
enough they will eventually succeed but at what cost and how much time.

Riggs.

 

I might just wind up doing both and have them both hooked to the key hole thing.

 

A cheap way is open the hood and take the ignition wire from the coil to the distributor on older cars. Most crooks won't carry a spare ignition wire with them.

 

thats a simple way to do until I get all the wiring setup for a much cleaner way to do it

 

Lets look at the options;

Ignition kill- to defeat, open the hood, find a 'Hot Wire' and connect it to the distributor/coil. guy (and your 'Vette) are gone 30 secs if he knows the general layout.

Starter kill- fine, until he shorts the big wire to the small wire.

Fuel cut-off. perfect, he's stranded, in the street. most thieves aren't going to hang around to troubleshoot, cops will get word and tow it to safety. Best place to mount it would be at the rear of the car, in the tank to steel line connecting rubber line. Beware though, Cut that line and the ENTIRE TANK will drain non-stop, so clamp it up-stream, before you do. You could also rob a impact fuel sensor out of a the wrecking yard, and hook this to it for added safety. I'm thinking this is my next project.

 

Yea I really like the fuel cut off and also the impact sensor(I have it on my f150 where it cuts the fuel if I get in a wreck)

 

All well and good for your F150...this is because your truck is fuel injected and uses an electric fuel pump that is in the fuel tank. And that is the way Ford designed it to be so you do not have fuel spurting out all over the place...because it is under pressure...after an accident.

GM uses a oil pressure/fuel pump cut off switch that cuts off the fuel pump on fuel injected Corvettes (84-96) when the oil pressure gets low enough. SO if the engine dies after an accident...the fuel pump stops running....due to low or no oil pressure.

The fuel is under pressure between the fuel pump on the engine and the carburator. The fuel coming from the fuel tank to the fuel pump is not under pressure....the fuel is being sucked from the tank. And eventhough the tank may have pressure in it ...depending if your fuel cap is vented or not vented...will still leak fuel out if it is ruptured in an accident.

I myself ...depending on the size of this fuel cut-off switch...would mount it BETWEEN the fuel pump and the carburator....if not down right beside the fuel pump. This is so that the fuel that is in the carburator is all the fuel the "punk" will get. And when they are trying to start your engine....the fuel pump is working....and will allow the fuel that is being drawn from the fuel tank to be retuned to the fuel tank via the return line....but not allowing any to get to the carburator....due to your switch. If you brought your car to me...that is where I would try to mount it...and get it plumbed into your hard lines.

"DUB"

 

Yea i got the idea from a 86 ranger i had, it had the impact cutoff on the passenger side interior firewall, just above foot level. About 2"x4"x3/4" it was, just a single 2 wire plug into it, guess it grounded through a mounting screw. Great little device. had a reset push plunge on top. would want to mount it in contact with the frame, i would think, but out of the weather, need a point that will transfer the shock of any impact well enough to the device. This idea would also work well with an electric fuel pump near the tank instead, the impact sensor could be used with this as well, addressing the dry running fuel pump issue noted by DUB, but you would need some type of pressure valve to take take the place of the one in the fuel pump, so your gas will circulate. I'm sure ones available, have to look. I'll come up with some thing, if you don't first.

I like that idea from a mechanical point of view,, but theft deterrence works best with a little slight of hand, you want to leave the potential thief scratching his head, and putting it out in the open like that is a give away. 5 more mins possibly. The electric fuel pump idea would work best, I think, all things considered. I see my new project.

I wonder if It would be a problem, the fuel pump trying to pull through a blocked line, for the fuel pump. I don't think you would want to run it like that for any extended period, but you couldn't really anyway, the engine is going to run out of fuel quite soon anyway. I don''t see problem with the idea, once you consider that. It might be wise to hook up some type of hidden indicator though, so you don't forget, and have the car die on the on-ramp. it's gonna work. my next project. I already ordered the RV valve. C.

 

RunningMan373,Stephen87,
I was going to advise on installing an electric fuel pump...but with it being a 74 ...I personally believe the best place for the fuel pump is IN THE TANK...like GM designed in later years. But that is only my opinion...for what that is worth.

Stephen86, I installed a wicked theft system in a 1978. I used the sending unit for an 1982 and installed the fuel pump in the tank....installed a fuel pressure regulator. I used the factory fuel pump on the engine and made it a "dummy"pump so that it did not function but allowed all connections to be factory correct and to flow fuel properly..

I then worked the 1989 VATS security system into the car that has the mirco chip in the key so the car could not be cranked unless you have the correct value of chip in the ingtion key. I installed the 1989 theft detterant system also..which was activated by the power door locks. All of this was done without needing a computer. The blank area on the gauge cluster where a warning light could go was used for the flashing light so the owner knew that the system was set when exiting the car....and it showed "security" when flashing. I installed at-top by-pass switch so the t-tops ..when out...would not cause the "security" light to flash. The underhood swtich was also worked into the system so if the hood were opened...and the alarm was set...the system would activate.

The car had the fuel pump cut off switch and a starter enable relay so that if you bypassed the starter and got it to crank...there was no way to get the fuel to pump. I tested it several ways and the car would only go about 20 feet and die....because of no fuel pressure...which was regulated to about 7-9psi.

This was a major undertaking...and your car can also have this ...but it may be more than you want to do...due to you stating you are trying to stall the "punks" so to speak.

I know this may not have been any help...it is just top let you know that the options are quite limitless....depending on how far you are willing to take this security issue. Which the system described above can STOP me. But will not stop a flatbed from coming up and pulling off with your car.

"DUB"

 

I am always open to new ways of doing this but I may not want to go that deep into it but I also am going to need to make sure that the relay that I use is a closed on fail type so that way to get it to close the switch I cut the power to it and to have it open I have to have power to it so that way if they find the wire to it thinking that if they cut it it will open it it will actually stay closed

 

OK. got the electric valve from RV Parts, it can't be used. It's a great quality valve, but inside the flow hole is only 1/8". Fuel starvation in short order. may keep it, it's a pretty cool valve, and can handle/stop air flow as well, so i might find a vacuum application for it, but it won't work for a fuel line, in this application.

 

Almost all of them are going to be power (12V) to open, so no worries there. I think I'll call the valve manufacturer, to see if they make a 3/8" version, bet they do. C.

Looks like model 195 will work, 3/8" npt fittings and 3/8" orafice.

http://www.afcvalves.com/mod195.html

 

cool thanks for the info I really appreciate the fact that you told me.