i swapped in a 350 in place of my 305 a while back, and it seems like the car wants more gas when its just sitting. it will die everynow and then. the timming is fine, i have changed that a few times and it did fix it some,, but not completely. Now i used the stock 305 pump...is this feedin my stock QJET and beffed up 350 enough gas?

 

From what I have read and heard over the years the stock 305 fuel pumps are hardly adequate for the stock motor,let alone a bigger stronger motor.I would definitely look into upgrading my pump to feed that motor,there are many manufacturers out there..Carter,Holley,Edelbrock,and the list goes on.I have no experience with any of the stock 305 stuff as I bought my Z minus motor and fuel system years ago,but i hope this helps ya out.

 

yeah that helps, thanks for the info, i just didnt know if that was my problem or not. what are pros and cons of getting a pump that flows more? obviously a pro is gonna be more fuel to feed the beast. but does that also mean worse fuel mileage?

 

how bad of in idea would it be to get a stock 350 pump? or can someone give me some ideas on what to look for.. i mean i look in jegs and summit,, and there are alot to pick from. i just want to be able to put it in and thats it, no fabrications of hoses or anyting like that. so what would go right into my car no questions asked?

 

I doubt that's your problem. Weak fuel pumps are shown during high power situations, not sitting and idling. When it dies on you, have you pulled the air cleaner and checked for accelerator pump shot? If it's there, then you've got fuel, and you've got another problem.

I'd check for a loose electrical wire to the ignition system. Coils and distributor pick-ups have been known to have a circuit open when hot (and sitting and idling is one time they get hot).

FWIW, I have a stock replacement pump on mine - the pump that was on the engine wouldn't feed the stock LG4 when I got it running, but again, that was only under WOT and after several seconds in that state. This 2-1/2 year-old replacement pump feeds the modified engine with no problems, and I've had it up to 6300 RPMs under power.

The nice thing about a stock-type pump is the return line - helps to avoid vapor lock. Since 3rd gens didn't come with carb'd 350's, you'll have to ask for a 305 pump. But, there really isn't anything different between the pumps. Ask for an L69 pump, you should be fine.

As long as the pump you have doesn't have more than 6 or 7 psi at the carb, you aren't going to overwhelm the carb. It is possible to have higher volume but at the same pressure as a stock pump, so the carb isn't going to care that the pump can supply more volume - it'll just shut off what it doesn't need (the pump just fills the fuel bowl, nothing else).

 

hmmmm so in other words,,, my pump is fine. and it usualy shuts off when its cold,, not hot. even though it will do it when its hot to, just not as much.just when im like barely giving it gas, or just letting it idle at a stop.