View single post by edward_davis
 Posted: 07-01-2006 07:04 pm
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edward_davis



Joined: 07-06-2005
Location: Eugene, Oregon USA
Posts: 162
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 I have to agree with Mark's assessment.  I had a similar problem that was a result of my old pump alternately having no pressure and too much pressure.  I bought one of the new Facet pumps, a black Posi-flo pump rated for the lowest pressure, 1.5-4 psi.  This pump is a lot quieter than the older brass-cube pumps; it only makes noise when it's priming, after I initially turn on the ignition.  You can get this sort of pump at most auto parts stores, and they're relatively inexpensive.  

The new pump made too much pressure anyway, so I installed an adjustible pressure regulator in the trunk.  I agree with Mike, it would have been better to install it in the engine compartment; I had to use my pressure gauge to fine-tune the pressure regulator so that the pressure at the carbs was the appropriate amount, 2.5 psi.  I actually had to set the regulator slightly higher than 2.5 for there to be enough pressure at the carbs - at 2.5 psi, the carbs were sucked dry by the engine. 

My fuel system also has the bypass that Mark describes, but it wasn't enough to keep the carbs from flooding.  Since I have an aftermarket aluminium tank, I'm not sure that it has the correct restrictor.  I put my pressure regulator after the bypass and everyting works fine.

Here's a picture of my setup on JHPPG:

http://jhppg.com/gallery/1974-No-18713/DCP_0096

Here's the website for the Facet pumps:

http://www.facet-purolator.com/mcl/pages/frame_src/tech_frmsrc.html

I don't have any association with those folks, of course; I just got their pump to work in my car.

Be sure to check your oil for gasoline contamination after having the flooding problem.

Last edited on 07-01-2006 07:05 pm by edward_davis