Starting issue w/ new Edelbrock carb...

[randymbtech]

Hey guys, I'm having an issue with my new carb setup. I converted my TBI 350 to carb w/ a comp cams extreme 4x4 cam, edelbrock performer manifold, hei distributor, and an edelbrock 600 carb. I installed the proper Mallory return style regulator, (set at 5 psi) so I could use the stock electric fuel pump. The truck runs incredible, but has a hard time starting when it's hot. It starts up cold perfectly. The problem happens when the truck is hot, and I shut it off, then try to restart within a few minutes. I smell gas, and I have to hold my foot to the floor to get it started. I can't find a fuel leak, but I smell gas, like the carb is leaking back into the motor when it sits, and flooding it.

I removed the brand new Edelbrock, and replaced the needles, seats, and floats. I adjusted the new floats as per the Edelbrock directions, but it still sucks. I re-checked the fuel lines and regulator, but everything seems right. Has anyone had this problem?

I want to switch to a Q-jet carb, but I don't want to spend $300 and have the same problem. Any advice would be greatly appreciated. Thanks.

[Fast305]

Hey guys, I'm having an issue with my new carb setup. I converted my TBI 350 to carb w/ a comp cams extreme 4x4 cam, edelbrock performer manifold, hei distributor, and an edelbrock 600 carb. I installed the proper Mallory return style regulator, (set at 5 psi) so I could use the stock electric fuel pump. The truck runs incredible, but has a hard time starting when it's hot. It starts up cold perfectly. The problem happens when the truck is hot, and I shut it off, then try to restart within a few minutes. I smell gas, and I have to hold my foot to the floor to get it started. I can't find a fuel leak, but I smell gas, like the carb is leaking back into the motor when it sits, and flooding it.

I removed the brand new Edelbrock, and replaced the needles, seats, and floats. I adjusted the new floats as per the Edelbrock directions, but it still sucks. I re-checked the fuel lines and regulator, but everything seems right. Has anyone had this problem?

I want to switch to a Q-jet carb, but I don't want to spend $300 and have the same problem. Any advice would be greatly appreciated. Thanks.

The Edelbrocks are very prone to fuel boiling in the float bowls on a hot engine. When it boils it goes right into the intake and floods out the engine. I would look for some kind of composite spacer or heat reducing gasket to run between the manifold and carburetor.

[randymbtech]

That sounds like a great idea, I'll try that. Thanks fast305!

[whitelightnin92]

typical edelbrock carb, better than a leaking holley by far tho. it isnt too bad to live with.
i do have one stupid question. you dont pump the accelerator before cranking do you? just asking because some people seem to think you have to do that everytime you start it.

[randymbtech]

Nah, I only pump it once when it's cold. Thanks though.

[randymbtech]

Well, now I am at a loss. I tried a phenolic 1 inch spacer under the Edelbrock, and the problem was the same. I went down to a local specialty carb shop, and talked to him about the problem. He thought it was the Edelbrock, so I had him build me a remanufactured Q-jet to my engine specs. I installed it yesterday, the truck runs excellent, but the hot start issue is still there. It is MUCH better than it was w/ the Edelbrock, but I still smell gas when I shut the truck off hot, and it dosen't start back up without giving it some throttle.

I am thinking that the only thing left is the Mallory regulator is junk. Any ideas before I sell this thing? LOL.

[NEUMANNZZ]

what did you set timing too?

[randymbtech]

I don't remember what the base timing is, It's been a while, but I set the total advance at 32 degrees. I think it's right on the money, because when I use 87 octane fuel, it pings a little bit. When I run 93 octane, it dosen't.

[randymbtech]

I can't figure why it stinks like gas when I shut it off hot. I made sure that the fuel pump relay shuts off when I shut the key off, that's fine.

[NEUMANNZZ]

fuel lines touching the block or exhaust?
does pressure regulator get hot?

[Swims350]

gotta be the carb, probably as mentioned before, the need for a heat gasket. I bought the edelbrock heat insulator gasket for mine from autozone and it fixed mine.

quadrajets are the same way, they too have a heat insulator gasket.

If not then I'd think timing, but with what you said timing sounds right on to me. If nothing else retard it a lil and see if it helps.

Now I also had to block the return line on my monte carlo with an edelbrock because when it sit it would loose gas out of the filter. If you hit the pedal, whether it's pump it out hold it half open when it's hot does it make a difference?

[big red chevy]

my buddy has a monte carlo did the same thing it ended up needing a vented gas cap to release pressure not sure if same problem but may want to look into

[Swims350]

the charcoal canister is used to vent the tank as well, if it's not venting it must be plugged up.

[randymbtech]

Going to look into both of those ideas, thanks!!!