I've been trying to figure out a problem in the truck but haven't sorted it out yet. It seems like vapor lock. Starts AMAZING when cold. But turn the truck off hot and it'll start up again nice an easy within a minute or two of shutting off but let it sit for 5 minutes or more and it's a difficult start. I insulated the fuel line near the headers. I'm going to put more insulation on the other hard line running up from the fuel pump - havent done that yet. I changed the fuel pump just in case. If I open the hood right after shut off it seems to help with the problem a bit. Someone suggested try and carb spacer/insulator and see if that helps...
I had the same problem a couple of years ago with an Edelbrock carb. Hard starting when it was hot. After some internet searching, I found a super thick carb-to-intake gasket made specifically for the purpose of isolating the carb from engine heat/intake manifold heat.
GM used the same type of thick gasket (right from the factory) on Quadrajet carbs.
It solved my problem.
My car was a daily so paying a premium for premium at every fill-up was not something I wanted to do.
http://www.jegs.com/i/Edelbrock/350/9266/10002/-1
-- Edited by Chevy Dan on Friday 26th of August 2016 04:01:56 PM
Is this a new problem? what have you changed recently ? before the problem occurred.. Are you running a quadrajet? when is the last time you changed your fuel filter? What is new on the truck this year from last?? Headers??? Is the fuel line running too close to the headers.. Are the headers wrapped?? Some times you need to go back over the basics .. If you were not having this problem last year something has changed.. You can make a wood spacer of you have an old 4-barrel laying around for a pattern you can just use a hole saw to make the bore holes.. and sand them smooth.. I would say about 3/4 in Plywood should work.. But I am thinking if it ran fine last year then what has changed..Is it slow to crank or does it crank fine..???
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The insulator plate won't hurt but the carb would have to hit 180 to percolate the fuel . To hot to hold your hand on it for More then a second or two . Easy enough to check . Look down the bore and see if fuel is squirting out the jet , if the carb is cool or not to bad Id check the fuel pressure and float seat. if the pressure is over 5 psi it could be causing it to flood if the seat is weak.
Unfortunately smart a$$ answers are not helpful to fix the problem your having right now eh!!! I agree with Slim on checking the pressure on the pump.. However you will need to "T" the line to put a pressure guage on.. but simply to check would be to do a little test run around the block, with the air cleaner removed. when you back home and shut it down for the amount of time you say it takes for the problem to happen. open the hood make a visual inspection. make sure the choke valve is fully open with warm engine, get a light or a flash light, get comfy over the throttle plate of the carb so you have a good view straight down the carb bore before you touch the carb linkage. you should see a nice clean jet of fuel spray into the bore.. If not then you need check to see what is happening in the carb.. But look for the spray first.. You may have something other than a carb/fue;l problem.. Does it run fine at all speeds when driving..Is this an electronic GM HEI
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There is no elevator to success — you have to take the stairs.
So just to be clear Joe - you only have a problem with the edelbrocks carb and not what it's sitting on? I think I'm wearing you down. You'll be a Chevy in a ford guy soon enough!
Yes GM HEI. No other issues runs great, cold starts amazing. When hot and shut off starts right back up great unless it sits.
Same set-up I had. Edelbrock 600 on a SBC with an HEI and exactly the same symptoms.
To be honest, I wouldn't even bother taking the time to diagnose whether or not you have a "heat soak" issue, for the cost of a thick gasket and the fact that GM felt all Quad equipped cars and trucks needed a thick gasket, I'd just buy one and toss it on. I see this as being one of those "it can only help" situations.
Looks like it's pretty much sorted out. I picked up the edelbrock 9266 insulator gasket. they specifically for the performer carbs to prevent fuel percolating. Sounds like must be a common issue to me.
I installed the gasket suggested by Chevy Dan and immediately I'd say it's 95% better.
that's good glad to hear it's better. I have a 302 Ford with an aluminum intake, exact same carb and points distributor. It does the same thing. It's not as bad as yours sounded.
