1973 stock carb (1 Viewer)

[adavis]

I just posted for advice on upgrading to a factory vacuum advance distributor and it got me thinking.....I have another question about my 1973 F155. Mark rebuilt the factory 1973 Aisin and did a great job....it runs super nice. My only question is that when it sits for a while (anything over a week) it takes quite a bit of cranking to start. It's like the fuel drains off, but there are no leaks. I choke it and pump quite a few times before it fires. It starts right up and idles great, but I am just wondering if something is wrong that would cause it to require cranking for so long? Once it fires up, if I kill it before it's warm it will fire right up again.....it's just the initial starting that takes so long.

Any idea what might cause this, or is it just normal? Thanks for any suggestions.

 

[charliemeyer007]

Seems normal to me for a carburetor engine, gas evaporites. Fuel injection has spoiled folks for instant starting. Plumb in a cheap diode electric fuel in line with your engine driven one. When you turn the key to on you will hear rapid ticking as it primes up the system, when it quits ticking - mash the gas pedal once, then set the choke, release the pedal - crank; it will start right up. That's how I do my 72.

 

[miller]

I have a 70 carb that I rebuilt and does same thing. The bowl drains down after several days so takes time to fill it back up. It seems pretty common. You can do a search for carb bowl draining to get more info.

 

[adavis]

Thanks for the input. I assumed it was normal, since it runs so well once it fires up, but I figured I'd ask just in case there was a simple fix.

 

[brooklyn]

Same here — that’s why I sometimes read the Sniper fuel injection threads. But, the cost is too much for me when I can just try and be patient starting the truck

 

[65swb45]

Very, very normal. RFG is more oxygenated, which is most of the problem, as well as being ‘lighter’(less likely to clog fuel injectors), which also makes it more prone to evaporation. Not a big problem in a ‘closed’ EFI system.

as I tell customers on a regular basis, I’m just glad that what is dispensed at the pumps in 2024 even works in our ancient vehicles.

When the change first happened back in the ‘80s I was more concerned, and I installed an inline electric pump on a toggle switch and a Stewart Warner fuel pressure gauge to tell me when the system was fully primed before turning the starter over. That was in my SBC K5, which was a very thirsty beast.

 

[adavis]

Very, very normal. RFG is more oxygenated, which is most of the problem, as well as being ‘lighter’ , which makes it more prone to evaporation. Not a big problem in a ‘closed’ EFI system.

as I tell customers on a regular basis, I’m just glad that what is dispensed at the pumps in 2024 even works in our ancient vehicles.

When the change first happened back in the ‘80s I was more concerned, and I installed an inline electric pump on a toggle switch and a Stewart Warner fuel pressure gauge to tell me when the system was fully primed before turning the starter over. That was in my SBC K5, which was a very thirsty beast.

Thanks Mark. You can disregard the voicemail I left you today.

The carb is still working great and I will just continue to be patient when I wake her out of slumber.

 

[65swb45]

Bumping this for the guy that left the voicemail at my shop a couple of days ago. If this is your only problem, you don’t need a rebuild; you just need patience.