Need Vacuum Solenoid

[TheSilverBuick]

To be Debbie doubter, what if the vacuum can/lines rupture? Why not run the filter before the priming pump to reduce the reservoir? Again, only wire the pump to kick off if the inertia switch or kill switch are hit so that the injection pump maintains prime unless an emergency occurs.

[DanStokes]

TC - my ears are open! I have the turbo modified for a bit more pressure and about twice the volume. I know the pump needs some mods to get the effect of the turbo.

Randal - the thing will run a long time on the contents of the fuel filter. Diesels will idle forever on not much fuel. I really think I have a fairly simple solution given the factory arrangement. I don't know what German brainiac decided to make the engine stop by applying vacuum, or why they didn't just put in a solenoid in place of the vacuum thingie.

The way it works is that the vacuum deal inside the injection pump forces the rack back to the point that no fuel flows. No fuel flows thru the injectors so they don't lose prime either. This leaves the whole rest of the fuel system charged with fuel and ready to fire up as soon as the key is cranked. Anything that kills fuel ahead of the pump would require repriming the system before the engine would run again. By using a vacuum can and a NO solenoid any time I remove power the injection pump gets vacuum and the engine stops. Just what the ECTA ordered and it works for a regular shut off as well.

I've chased my tail on this a lot and I'm pretty sure this is as simple as it can be done and meet all the requirements. I'm really NOT one to overthink stuff - you can ask ME!

Dan

[TC]

It's actually not easy to make a Diesel (at least a M-B Diesel) stop running when the battery power is cut. Being fully mechanical and requiring vacuum to make it die it takes some thinkin' cap time. I THINK I have it sorted. We'll see when I fire it up for the first time.

Dan

I didn't know you were working on a Benz diesel, 5 cylinder I presume....... I rebuilt quite a few of them when we had the Benz business, there's a trick to getting more power out of them it, do you know about it??

[TheSilverBuick]

Dan, perhaps we are over thinking the problem? Or I missed something. How does the injection pump get the fuel? Couldn't you simply shut off the fuel to the injection pump? I know you aren't supposed to starve the injection pump, but what if the priming pump was wired into the cut off and intertia switches so it was only starved "in an emergency"? If you cut fuel to the injection pump how long before the engine shuts down? Then maintain the vacuum switch for "normal" shutting off of the engine? Then one of those Evap switches could be wired to a momentary switch to shut the engine off.

[DanStokes]

It's actually not easy to make a Diesel (at least a M-B Diesel) stop running when the battery power is cut. Being fully mechanical and requiring vacuum to make it die it takes some thinkin' cap time. I THINK I have it sorted. We'll see when I fire it up for the first time.

Dan

[Deaf Bob]

Thanks guys. The cruise control solenoid might work but I have a call in to Peter Paul Electronics and will pop the big bux (~$50) for an instrument grade 12VDC 3 port solenoid. I KNOW that will work and should be durable. They're supposed to get back to me today so we can get it ordered.

One of the drawbacks to working in instrumentation for so many years is that I know what the good stuff is and sometimes it's hard to settle for the "good enough". The Monarch tach (on order), the pyrometer (here) and other goodies like that - I'm used to these things and am comfortable with them. I posted this thread hoping that there was a common salvage yard part that would work just as well, but my fussy got in the way.

Again, THANKS

Dan

Dan, the way I see it, better to be fussy and alive than..... Ya know...
After all ME needs you as much as you need her!

[DanStokes]

Thanks guys. The cruise control solenoid might work but I have a call in to Peter Paul Electronics and will pop the big bux (~$50) for an instrument grade 12VDC 3 port solenoid. I KNOW that will work and should be durable. They're supposed to get back to me today so we can get it ordered.

One of the drawbacks to working in instrumentation for so many years is that I know what the good stuff is and sometimes it's hard to settle for the "good enough". The Monarch tach (on order), the pyrometer (here) and other goodies like that - I'm used to these things and am comfortable with them. I posted this thread hoping that there was a common salvage yard part that would work just as well, but my fussy got in the way.

Again, THANKS

Dan

[TC]

Hey Dan would this work, it does say it's normally open..... It's a vacuum switch to active the lockup on an automatic that has a lockup converter.... There are others with different vacuum ranges, just search "Lockup Vacuum Switch" and others will appear, here is what I found....

http://www.ebay.com/itm/Adjustable-Universal-Vacuum-switch-1-6-inHG-lockup-700r4-2004r-350c-superior-/300824732720?pt=LH_DefaultDomain_100&hash=item460a8d2430&vxp=mtr

[TheSilverBuick]

I'm pretty sure no, but I can track them down tomorrow and double check. The evap one opens with power and the cruise control one closes AND vents the vacuum when switched off.

[DanStokes]

Thanks Randal. THAT'S what I was looking for. Are either of those normally open?

I did send off an E-mail to Peter Paul (major makers of solenoids) to see what their stuff would cost. They're supposed to get back on Monday according to their computer-generated response.

Dan

[TheSilverBuick]

Tons of Evap vacuum switches out there and some old cruise control unit ones that will probably work for you.

Here is something I made to control my Thunderbird's vacuum head light doors when the OE valve failed. I used this until I finally broke down and bought a rebuilt OE valve.

The top one is an evap valve on all sorts of GM cars for a dozen years (on the carbon canister). I think a nipple should be threaded into the port pointed at the screen, unless you are simply going to leave it open to the air to bleed the vacuum. The bottom one is the vacuum release valve from a cruise control set from the '70's.

[Barry Donovan]

subaru has one, I saved 3 of them, 20 years old, errorless.

I think they called them purge valves, but easily made a switch.

they are getting 106 bucks for them for reasons i could guess.


tiny little valve.

or you could look purge valve at ebay (they are the damn control valve)
just look for electric version.
funny enough, what you want as normally open..you can change your mind and go normally closed. that is why I kept the valves, they can do anyhtng..a bit like a relay to electricity, except its vacuum.

I see delphi for gm and the dodge viper is a few beefy examples

[Beagle]

I was actually serious about the nasal aspirator.

http://www.nostalgicairparts.com/air-conditioning/vacuum-actuator-solenoid-412.php

[TC]

Dan fallow the link I'm sure something will work.....

http://www.ebay.com/sch/i.html?_odkw=fuel+pump+vacuum+switch&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313&_nkw=vacuum+switch&_sacat=0

Or this one.... I added 12v to the search...

http://www.ebay.com/sch/i.html?_odkw=vacuum+switch&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313&_nkw=vacuum+switch+12v&_sacat=0

[TC]