recently updated thread 1987 305 carb complaint

 

Was the car origionally carb'd? or fuel injected? It sounds like it may be a fuel pump problem, generally fuel pumps send fuel in fluid motion (not pulsating)

 

car is original carb 305 installed new fuel pump today starts easier but still off idle poor excelleration did notice a large flow coming out return line back to tank almost as if pump was working . blew compressed air thru both lines to tank but found a large vacume when removing gas cap . please any ideas im a old pontiac guy my first chev powered pontiac with flat spot off idle????????

 

I don't believe you mentioned what carb it has.

p.s. it's "acceleration".

 

your correct aceleration! it original equiptment chev 305 with original quadrajet electric control main metering? at times previously found heavy start up smoke white/blue intermitently .when occurs very slugish throttle . carb was rebuilt previous to purchase looked in air horn when vehical was off pumped acerator pump dry like older quad that ball not seated . disassemble carb lip seal looked good replaced same occurance. replaced fuel pump today same hesitation no smoke start up? found return line which goes back to tank to be flowing large volume even filled pump and carb . vacume in gas tank when opening ??? any other info adjusted timing no change ?