78 460, LONG Cold Crank to Start... Ideas?
 

78 460 with an Edelbrock Performer, mechanical fuel pump and inline pressure gauge...... Clean filter..... Let the truck sit for 2 to 3 days or more, and the pressure gauge reads absolute zero.... Set the choke, crank the starter, and it has to crank it's brains out for 30 seconds to get gas and fire. After that, it starts right up every time, and instantly. Cold crank is driving me nuts. What are your thoughts? Fuel pump? Carb float? There are NO gas leaks...... Zero. I'm interested to hear what you'se guys think.

Before my 79 460 quit working on me (no compression), it would do the exact same thing. Needed a lot of cranking to get gas to the carb. After the initial hard to start, it would fire right up if driven everyday. I'll be watching for an answer as to the why.

Performer is an intake, I assume you mean Edelbrock AFB carb.

This is one of the reasons I hate them, I have several that have done this since they were new. I have no idea why. put a 4160 on and they start instantly. the fuel is draining out of the float bowl and I don't know how you stop it, or where it's going.

If it's not an AFB what do you have it can probably be fixed.

ethanol fuel likes to evaporate out of fuel bowl faster than e-free gas. Happens over the course of a few days. Hot weather effects it more as well..
Not saying this is your issue but something to keep in mind while tracking it down.
My 460's do the same.

Try a anti back flow check valve. https://www.siliconeintakes.com/liqu...d--p-9581.html

try a cooler thermostat, better gas (91 octane or better yet- avgas lo lead 100) and follow up before winter. If you don't want to try this, then let it set an hour, start it and run it 5-10 seconds and let it set another hour, start it and let it run 5-10 seconds and by then I bet it will have gas in carb and not be soooo hot it boils it. Remember when a carburetor is running, it draws air through and cools it keeping gas from vaporizing. as soon as shut off it boils gas and heat soaks. just some thought to try.

ALL of my trucks do that. Drives me nuts too. 460, 400, 351m, 6 cyl... you name it. All have edelbrock carbs except for the 6cyl. thats stock. Thanks for the anti backflow check valve suggestion 77&79f250, I have been thinking that would solve it for a while now, and you just made me order a few!

I'm noticing a trend. I have an Edelbrock AVS2 currently because so many people were raving about them, the throttle response is amazing compared to the normal 1406/1405 but immediately after taking a holley off and putting the edelbrock on cold starts are terrible. It also seems to slowly flood after shut off and bleed all the fuel pressure off. Then I go to start it after a few days and it ends up flooded even if I give it like one pump. I only got rid of the holley because the secondaries kept leaking and all I could decide on was that the seats were too worn. But the holley would always fire off immediately with one pump.

Yeah, the comments here and on previous threads are all the same. I'm going to try a check valve inline to see if it helps the problem. Makes sense, and for the price it's worth a try.

The exit valve in your fuel pump is an anti-backflow valve.

Well if it is, it doesn't seem to be working. At all. NO finely tuned engine should take 30 seconds or more to be fed with gas. Just ridiculous.

Then either your fuel pump needs replaced, or your POS carb does. you shouldn't need JC Whitney accessories to start your vehicle.

Does any reputable company make a higher volume mechanical pump for a 460............? I've seen a number of "Pro Comp" pumps but know nothing about the company.........

Volume from any pump that will fit it is plenty.

Good luck, I changed the pump on mine and it didn't fix the problem.

it does with todays crappy gasoline. get a fuel pressure gauge and see what psi you get with it running.
Mechanical pumps usually work or they don't. There are exceptions like the pump I replaced on the 86 with a 460. after cooling off it would start and run for about 10 minutes and than stall.
Would not restart at all unless you put gas in the carb. Replaced the pump and problem solved. Never experienced that with a mechanical pump before.
If I don't start my truck after a week or more I must pump the pedal several times and crank it for longer than I wish for fuel to fill the bowl.
I'm sure if I spliced in an electric pump, it would solve that issue but I'm waiting on this new mechanical pump to fail before I go down that road.
I read this alot with edelbrock carbs, just do a search you'll find this on jalopy and other auto forums besides here..