I brought my 61 Dynamic 88 back from the dead after 20 or so years of sitting. The more I drive it, the more crap is breaking. I need to address my fuel pump. I can buy a rebuilt dual for $130 on ebay or a rebuild kit for $69 plus shipping. My question is...Is there an advantage or disadvantage to putting just a plain ole' mechanical fuel pump on and putting in a vacuum reducing valve from the manifold?

And by the way, this vacuum reducing valve...Is it an actual valve? or a fitting to reduce the size to the 1/8 vacuum line?

FYI-I'm not restoring this to original. I'm just getting it reliable for a daily driver.

Thanks
Gary

 

I don't see why you couldn't. The reason the HVAC vacuum was sourced from the fuel pump was because there isn't as much variation in vacuum from the fuel pump diaphram as engine load changes as there is running it from manifold vacuum, and they were trying to avoid the system switching modes if say, engine was struggling up a long grade where there would be very little manifold vacuum. Ford did the same thing with their vacuum windshield wipers.

Run it off manifold and hide a vacuum storage ball somewhere, and I think you'll be fine. If I were going to do all that, I'd use an electric fuel pump and get rid of two problems.

BTW, welcome to the world of early-60s Oldsmobiles.