FYI FORD MustangSteve's Ford Mustang Forum / Hot start issue

**Posted by Steve69** 9/09/2024 8:07 AM

Hey Guys,

I have a Summit Racing carburetor. It runs good. After Its warm and I shut it down for more that 5 minutes it has a hard time starting. Like theres no fuel. If its only a couple of minutes it fires up like it should. I have the fuel lines wrapped in heat covering. I bought a old style foxbody fuel pump with a return style line back to the fuel tank.

After I ran it let it sit for 10 minutes. I figured I check the fuel bowls on the carburetor while engine is off. The rear bowl was 3/4 full. The front was less than half. I did notice the fuel moving around the bowl and the car was still. I wonder if its boiling and maybe causing the issue of warm start problems. Im debating on installing a Holley heat shield and see if this fixs the issue. Anyone else have any issues like this with there carburetor.

Thanks
Steve69

**Posted by pbrownrk** 9/09/2024 8:32 AM

I have a Summit carb on my 1966 Ranchero with a stock 302. I can go to the market and shop. When I go to leave it does not want to start. Running and engine off the bowls are at 1/2 full. This has been a persistent problem. I carry a jump pack because it will run the battery down trying to start the car.

**Posted by rpm** 9/09/2024 9:46 AM

Make sure your carburetor has a spacer between the intake manifold which keeps the carb cooler.

**Posted by MS** 9/09/2024 9:59 AM

I installed a 500 cfm Summit carb on Jose’s 65 with a rebuilt 5.0. It does not exhibit any starting issues. Always starts at the touch of the key, cold or hot.

Maybe you need to adjust float levels or install a new needle/seat assembly.

I have never believed in all the bandaid solutions you guys are discussing.

**Posted by Bentworker** 9/09/2024 10:20 AM

Steve- Not everyone has the luxury of pure Texas gasoline. Out west we are burning whatever blend of garbage is sold at the pump. I wouldn't label a phenolic spacer as a band aid.

**Posted by Steve69** 9/10/2024 7:21 AM

pbrownrk wrote:
I have a Summit carb on my 1966 Ranchero with a stock 302. I can go to the market and shop. When I go to leave it does not want to start. Running and engine off the bowls are at 1/2 full. This has been a persistent problem. I carry a jump pack because it will run the battery down trying to start the car.

That sounds like a PIA.. Mine will start if I pump it a bit or hold the pedal to the floor while cranking. I ordered the heat plate from Summit and I might add a spacer too. It that doesn't work maybe try what MS suggested with the needle and seat and adjusting the fuel levels. I always run Kwik Trip premium fuel with not Ethanol. Works great in anything that has a carburetor.

**Posted by BobE** 9/10/2024 7:30 AM

Steve69 - if you install a spacer, I would avoid an aluminum version. While aluminum will dissipate heat quickly, it will still transfer heat to the carb. The phenolic/wood versions will insulate the carb better.

**Posted by Rufus68** 9/10/2024 9:43 AM

What procedure do you use when attempting to start it hot?

**Posted by TKOPerformance** 9/10/2024 11:47 AM

I've often heard the fuel blamed for hot start issues, because most fuel has ethanol in it now. I don't know that ethanol fuel would make a difference since the boiling point of ethanol is actually higher than gasoline.

When these cars were new they typically had a cast iron manifold with a carb atop an aluminum spacer. That seemed to work fine and not create hot starting issues. So IMO if there's an issue its not related to such a combination, and an aluminum manifold would be even less likely to cause issues.

If the float bowl is 1/2, 3/4, or full I don't see that being an issue in it starting. Its got gas. So unless you run the bowls dry cranking it and they can't refill not sure why it would matter. If they don't refill I'd suspect the needle and seat, which I have seen ethanol damage and cause issues.

**Posted by Ron68** 9/10/2024 2:15 PM

I had a hot start issue once with the 68, which had an aluminum spacer under the carb. On hot summer days where I had been driving a long ways on the freeway, when I'd pull off, it might stall and be hard to start. I switched to a nylon spacer and it was no longer an issue.

**Posted by rpm** 9/10/2024 4:35 PM

I'm using this 3/8" hear soak gasket.

**Posted by Rufus68** 9/10/2024 4:57 PM

Are you depressing the pedal half way and holding it while starting the car hot? This is the procedure outlined in the owner's manual back in the day. This works by allowing more air into the mix during starting.
Do not release the pedal nor pump it. The intention is for more air not more fuel.

**Posted by Rufus68** 9/10/2024 5:04 PM

**Posted by 6sally6** 9/10/2024 5:43 PM

Rufus68 wrote:

I find it 'funny' the instructions show a female pressing the accelerator....(or a California man...
calm-down...J/K)) Although those are nice pumps !!!!!
6sal6

**Posted by Rufus68** 9/10/2024 5:54 PM

And they wonder why the Mustang was originally called a secretary's car

**Posted by MS** 9/10/2024 6:28 PM

I think the assumption was that only a woman would need instructions on how to start a car

**Posted by Rufus68** 9/11/2024 4:06 AM

Better

**Posted by TKOPerformance** 9/11/2024 6:07 AM

You don't know how that foot identifies.