ZODIAC13

33 love working on old classic cars and trucks and looking for some helpful advice to fix my 1974 GMC Sprint have a 350 small block butt some days it'll start that has playing gas good fuel pump but some other days I have to stuff a hose and a rag around the gas tank and force air into it to force air up to the front of the car too so it can pump the gas into the carburetor and after that the car runs fine as long as I go out and started up everyday or every couple of days but when it sits for 3 - 4 days too long all the gas drains out of the line and the filter and everything and then it won't start does anybody have any helpful ideas of what the problem is I would really appreciate it if somebody could give me something to go on the car is a classic it is a rare car and I would like to get it fixed and back on the road can you help

Marshy

What carb is on it, Q-jet? Sounds like it could be one of two things. Either fuel pump is bad/going bad or the bowls of the carb are draining empty when it sits.

ZODIAC13

It has a Edelbrock carburetor 4 Barrel but it also sounds like and has a knocking on the top end of the engine so I was thinking camshaft but if it is the carburetor and the camshaft how could I fix that do I have to rebuild the whole motor and replace the carburetor or what

Marshy

Sounds like you have 2 separate issues to me. How much is a mechanical fuel pump anyways, why not just replace it and see if that helps? I don't usually recommend just replacing parts without some way to test it but fuel delivery system is quite simple and believe a pump replacement is cheap and easy. How many miles are on it, maybe replace the filters while your at it.


Would it be possible to capture the knock on video and post it for us to hear?