Jump to content
vairter

separate carb priming electric circuit

6 posts / 556 viewsLast Reply

Recommended Posts

The previous owner of my 1975 '02 wired up the electric fuel pump so that it begins to operate in the "Fahrt" ignition key position.  I've been using this position for a couple of minutes before starting the car in order to fill the carb (Weber 32/36) fuel bowl since I only drive the car every couple of weeks.

 

I just figured out that this procedure will also apply power to the electric choke heater, causing the choke to fail to close fully before starting.  Needless to say, this has caused me some grief in getting the car to cold start.

 

Has anyone tried to run a separate switch+fuse directly from the battery to enable operation of an electric fuel pump without using the ignition key, so that the choke isn't simultateously warmed up?

 

Terry

 

Share this post


Link to post
Share on other sites

You shouldn't need a few minutes to fill the float chamber of a carb with an electric pump. Few seconds max, assuming it's dry to begin with.

Share this post


Link to post
Share on other sites

Yeah, 5 seconds.

 

But it would be easy enough to wire the choke to a circuit that's

only on in the run position.

 

Your meter is your friend.

 

t

Share this post


Link to post
Share on other sites

I used a fuel pump relay from an E30. It allows the fuel pump to run only in start position or when there is a signal from the coil. Took some time with my multimeter and the E30 wiring diagram, but it works great and is safer in case of accident.

Share this post


Link to post
Share on other sites

and for added anti-fuel-death, the inertia relays from '80s Fords are good, too.

 

t

Share this post


Link to post
Share on other sites

We have do to it in our race cars.  We are required to run an oil pressure switch that kills power to the fuel pump in the case of no oil press.  We just wire in a momentary switch or button that bypasses the OPS to fill the carb so it will start without cranking for 10 seconds.

 

You only need to prime it for a matter of seconds 2-3 max.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.




×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.