solenoids.... I think

[Bill ThompsonNM]

Perhaps a strange request.. I'm looking to replace the cold start cable (now defunct) on my '82 VW diesel rabbit pickup with something else since I can't get a replacement. One idea I had was to replace it with something electromechanical, some sort of latching solenoid? Basically I need to be able to move a lever about 1 inch. One direction advances the injection timing slightly when cold, the other is the normal setting.

Any suggestions as to what type of device to search for? and where?
I'm good at wiring and electronics.. but I haven't needed this kind of functionality before. Thanks.. :confused:

[Lee Schierer]

What about a pull choke knob on the dash like old cars used to have. Sort of like the gas lever on your push lawn mower.

[James Malcolm]

You could start at McMaster-Carr (www.mcmaster.com (http://www.mcmaster.com)) and search for solenoid. They have a few 12v models w/ 1" stroke starting at < $20.

[Scott T Smith]

70's and 80's vintage GM auto's with quadrajet carbs often had a small 12V solenoid on the carb to increase the idle when the AC was turned on. It only had a short travel though.

Another option is a solenoid used to turn off the fuel to a mechanical diesel injection pump. These are quite common, and probably your best choice. Most 70's - 90's vintage diesel engines have them.

A third option (and the least expensive) is a solenoid for an electric trunk release. They sell for around 12 bucks and have a cable coming out of them. They are unidirectional, so you'd need to put a return spring on the lever to move it back.

[James Malcolm]

Go with one of Scott's recommendations. Much easier to find a replacement part in a pinch from any auto parts store...

[Larry Edgerton]

Bill, you lucky dog! Those are cool little rigs.


Always kind of wanted one. Now with my jobs so spread out I could really use a small truck with that kind of mileage.

I like the idea of one you can control manually, it would be great for tailgaters................

[Bill ThompsonNM]

Rumor has it that vw is reintroducing a pickup. Probably more power but good mileage. My wife's diesel jetta wagon consistently gets almost 50 mpg.
I've wanted one of these for years. Overall in good shape. Got it painted and fixing little things one by one.
You can still find some if you watch CL or check junkyards who handle vw's. They usually know who has one for sale.
I'm getting about 45 mpg. Might do better when I put new injectors in this fall.

The trunk latch solenoid sounds interesting. Otherwise maybe I'll look for some sort of universal mower cable and perhaps adapt that. No rush it's not going to be cold for a good long bit.

[ray hampton]

do bicycles still use handle-bars brake unit , strip your kids bike for the cable

[Kevin W Johnson]

A third option (and the least expensive) is a solenoid for an electric trunk release. They sell for around 12 bucks and have a cable coming out of them. They are unidirectional, so you'd need to put a return spring on the lever to move it back.

A better option would be a door lock solenoid, they move in both directions, but do require a reversing circuit. The trunk solenoid would require power applied the entire time it needed to be pulled in, otherwise the return spring would just pull it back out.

Im thinking the choke cable would probably be the simplest fix.

[Bill ThompsonNM]

;). Hmm. Of course if I picked up the signal from the engine thermostat I could use a door lock solenoid and turn it on and off automatically.

[Scott T Smith]

A better option would be a door lock solenoid, they move in both directions, but do require a reversing circuit. The trunk solenoid would require power applied the entire time it needed to be pulled in, otherwise the return spring would just pull it back out.

Im thinking the choke cable would probably be the simplest fix.


Kevin, from an operation standpoint, I think that the single acting trunk solenoid is a better option, and this is why.

If a single stage solenoid is used where power is required to enrichen the circuit, and a spring pulls the enriching lever back otherwise, you don't have to worry about potentially damaging the engine if the switch gets hit and the solenoid is on while running (too rich a mixture will wash the fuel off of the cylinder walls, dilute the oil and result in accelerated piston to cylinder wear). Basically the spring is always holding the enrichment circuit in the "off" position, until being overridden by the solenoid.

Also, by requiring a "momentary interrupt" type of switch to activate the solenoid, you have a second "fail safe" in the system.