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Fuel system question

This is for one of you 'very mechanical' guys. I need to know if an original Carter fuel pump on a '55 V-8 would have an 'anti drain back valve' in it. Here's my dilemna. After sitting a week or so, I give the gas pedal i/2 throttle, let off, hit the key and it fires before the engine turns over once. Good huh! HOWEVER, if I don't blip the throttle immediately after it fires and the engine dies, I have a hell of a time getting it to fire again. It takes way too much cranking before it fires. It seems as though there's enough fuel in the bowl of the carb to give it a squirt with the 1/2 throttle, but before the carb the lines are dry back to the tank. A properly operating anti-drain back valve would not allow the fuel to siphon back to the tank. Bye the way, if the car sits for less than a week, the above scenario does not happen. The car fires off and stays running. The pump that is on the car now is one of those cheapo Airtex pumps. Thanks for your thoughts Dexter

Reply to
dwcars
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Not per se, but the check valves that are a normal part of any mechanical fuel pump should prevent drain back.

A week is pretty good, really, I don't know that I'd be overly concerned about it. You probably didn't notice the same issue on your daily driver back in the 70s or 80s because, well, you drove it every day.

nate

Reply to
Nate Nagel

Reply to
dwcars

no yo uwere right the first time, it was a carter. the sixes used A/C.

nate

Reply to
Nate Nagel

Dexter, no "anti-drainback" valve, as such. Not needed. The fuel inlet is at the top of tha carb bowl, and there is an air cushion above the normal fuel level. So even if the standing fuel in the line to the pump were to drain back down, the vacuum developed could not suck fuel out of the carb bowl.

If the carb bowl is going dry, one of two things is likely happening: either the bowl is porous, and fuel is leaking out, or the fuel is simply evaporating. Modern gasoline has a higher vapor pressure than what was the norm when the car was new, so the latter is a distinct possibility.

If the car routinely starts, after a long sit, after 10-20 seconds of cranking, I wouldn't let it worry me too much. At least you should have oil pressure before it lights off. Starters are cheaper than a set of engine bearings.

OTOH, if the car is hard starting after ANY duration of stop, them you may have a percolation or vapor lock problem.

Gord Richmond

Reply to
Gordon Richmond

Problem......... gas evaporating out of carb. Solution............. electric fuel pump. BTDT

Reply to
Jerry Forrester

Amen to that... All of my cars operate on electric fuel pumps!

JT

Jerry Forrester wrote:

Reply to
Grumpy AuContraire

It doesn't necessarily have to 'operate' on the electric fuel pump. One could just use the electric pump to refill the carb. The manual pump will pull the fuel through the electric pump when it's not needed.

Reply to
Jerry Forrester

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