Hard time starting when engines warm???

[romes20]

Hi everyone, here is my problem. When cold starting the truck turns on perfectly fine but when I turn it off and say run into a store and come back out. I try turning it on and the engine turns over but has a problem actually firing up. Sometimes I have to try this a few times before firing. I've been trying to do some research and came up with "heat soak" or installing a heat sheild or phenolic spacer on the carb? Sorry I'm fairly new with all this so if someone could help me out that'd be great. It also replaced the battery about a month ago so thats brand new.

Thanks in advance,
Jared

[Rons86]

I know I'm on the wrong forum, but I had the same problem with my 86 using a 1406 Edlebrock carb and alum. intake. I solved my problem by putting a 3/4" spacer (wood laminate or composite) between the carb and intake. Took about 15 minutes and solved the problem immediately.

[Shyguy]

Edelbrock carbs have a tendency to have fuel boil problems when turned off hot and usually a phenolic spacer helps.

Edelbrock carbs seem to like fuel pressure constant below what a stock fuel pump puts out also.

[romes20]

awesome thanks guy, I have ordered the spacer.

[kevmic28]

I have an adapter plate between my ED carb and the stock manifold and still have the heat soak problem. Only does it when temps are over 90. It was way worse with the rochester on it though.
I have wondered if adding an electric fuel pump would help.

[Shyguy]

How thick is the adapter? The phenolic spacer is not really an adapter, it is a spacer to prevent heat getting to the carb.

An electric fuel pump might help, but you will also need a pressure regulator,

[kevmic28]

Its actually pretty thick. About 1/2 to 3/4 of an inch thick. Made from aluminum.

[Shyguy]

Originally Posted by kevmic28

Its actually pretty thick. About 1/2 to 3/4 of an inch thick. Made from aluminum.

Yep, that us pretty thick and should have been good.

Sounds about like the one my son is going to use on his 454.

[kevmic28]

I have an Edelbrock performer intake that I have had for a while but have not gotten around to putting on. I may switch it over with a spacer once it cools off outside.

[Andy4639]

My 71 had the same problem until I installed the mini starter. My 71 is Fuel injected so it wasn't a fuel problem.
Link:


http://67-72chevytrucks.com/vboard/s...d.php?t=417721

[romes20]

Once I get this spacer will my carb need to be re-adjusted???

[68 IRON]

I'm interested also....son's truck does the same thing. Edelbrock carb....didn't know those had a problem with heat. As far as adjustment...I wouldn't think so. Here we go....To The Top!

[Eddie H.]

You can't use an aluminum spacer, because it conducts heat. You need a phenolic spacer in order to insulate the carb from the manifold heat.

[BIGKEV]

What is your initial timing???

[romes20]

My spacer showed up today so I will install it and let you know if anything changes. Sorry how do I determine my initial timing? Im a newbie with engines.

[Rons86]

Your carb will not need readjusting. Get a timing light to adjust engine timing. There are lots of threads on this procedure.

[c10seconds]

I had the same problem. It was because my starter was getting hot due to the headers being so close to it
Posted via Mobile Device

[MagmaJct]

Gasoline has undergone changes over the years that old carburetted engines are just unable to adjust for. The major change is the oxygenation of the gasoline. Not only is that gas "leaner" to reduce CO emissions, but it also has a lower vapor point than gas of 30 - 40 years ago.

When the engine is running the carburetor gets a sufficient supply of cool fuel from the tank with minimal heating from the engine and related components. However, when the engine is shut off, and the cooling system is stopped. The heat is allowed to soak into the carburetor and the fuel system around and including the pump. This makes the gas vaporize and even "boil" out of the float bowl and into the intake manifold.

Not only does this flood the engine, but the vapor build up in the air cleaner causing a very rich mixture. In many cases the easiest way to get the engine started is to gradually press down the accelerator while cranking the engine. As it starts let off enough to maintain a stable RPM to purge the engine of the rich mixture.

This is the procedure I've used for years. Ideally, I'd like to find a phenolic spacer for my VW, but it seems I'll eventually have to make my own. I eventually found one for my truck, and it seems to work well. However, I will eventually install the Quadrajet.

[oldblue1968chevy]

what carb ya got

[romes20]

Originally Posted by oldblue1968chevy

what carb ya got

Im running the Edelbrock Performance Series 750 with a manual choke.

What I did lastnight was took the carb off, cleaned it carb cleaner and decided to put it back on to see how it ran before putting on the spacer. Well it started a lot better (even when hot) but now it just doesnt sound right. I've been doing some reading on here and the internet and people have recommended playing with the mixture screws while checking out the accerlator pump.

What should I be checking next? Please keep this as simple as possible because Im a newbie trying to figure this out

Thanks.

[BIGKEV]

Tell us everything you know about your engine combo!! Heads, cam, CI, intake, CR, fuel system, air cleaner, ignition setup! It sounds like there may be a few issues at play here.

[romes20]

Originally Posted by BIGKEV

Tell us everything you know about your engine combo!! Heads, cam, CI, intake, CR, fuel system, air cleaner, ignition setup! It sounds like there may be a few issues at play here.

From what I know its a 350, hooker headers, edelbrock intake, edelbrock air cleaner, MSD Ignition, not sure of the compression ratio or anything else as Im unable to look at the motor right now.

[stsalvage]

well the spacer is a good one timing is another.Is your motor grounded do you have all your grounds hook up are you running a one wire alternator or the old factory one.your power cables and ground cabled should be check and if you see them turning green best off to replace them with Big thick ones the more copper threads the better.make sure all your bolts are tight and change the fuel filter check your cap and rotor

[oldblue1968chevy]

what fuel pump, maybe too much pressure and running rich (mine is I know..)