Overheats and stalls

CHRISBENJAMIN

MEMBER
1967 FORD MUSTANG
V8
2WD
AUTOMATIC
400 MILES

I have a 351 high performance small block with 310hp the engine. It does not show to hot on the temperature gauge, in stop and go traffic the engine stalls and will not accelerate. I have installed a lower temperature thermoset and after driving and letting it sit at an idle the engine stalled and wound not accelerate. The intake gets very hot could it be some kind of vapor lock.

Thursday, August 26th, 2021 AT 9:39 AM

3 Replies

ASEMASTER6371

MECHANIC
52,797 POSTS

Good afternoon,

The first thing I would check is the fuel pressure.

The pressure should be 5 to 7 pounds. Any lower, it could boil causing vapor lock.

Beyond that, the carb is most likely the issue.

What kind of carburetor?

Roy

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Thursday, August 26th, 2021 AT 1:24 PM

CHRISBENJAMIN

MEMBER
2 POSTS

I have a Holley Street Dominator intake with a Holley 4150 650 CFM 4 barrel carb. I ordered a high output thermostat and new gasket from Holley to install to see if that helps.

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Thursday, August 26th, 2021 AT 2:34 PM

ASEMASTER6371

MECHANIC
52,797 POSTS

There is no such thing as a high-performance thermostat. All the thermostats have the temperature set for opening.

I would do a leak-down test on all the cylinders and check for a failed head gasket. That is where you remove all the plugs and insert shop air into each cylinder to see if there are bubbles in the radiator.

https://www.2carpros.com/articles/head-gasket-blown-test

Roy

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Thursday, August 26th, 2021 AT 4:17 PM