Car tries to start, but stumbles and shuts off

Hello, I'm Danny.

Just to add my 2 cents there is something you need to know about Holley carburetors. Any time you have a backfire through the carburetor it blows the power valve and needs to be replaced. Even if you replace the valve and have another backfire it has to be replaced again. This is most likely the reason you car is running poorly. There is a conversion kit that is offered to prevent power valve damage in the event of a backfire.A hole is drilled in the primary metering block and a check ball and spring is installed. Hope this helps and thanks again for using 2CarPros.

Hi,

I would think if the power valve was bad, it would not change. In other words, it wouldn't be good one time and not the next. However, he is correct about the backfire causing damage to it.

Have you had any progress with it?

Joe

Not a problem. Let me know what you find when you get to it.

Take care,
Joe

Hello again.

Yes, the performance would be affected by the power valve after a backfire. After getting things sorted out I would definitely change the power valve to improve performance from the carburetor. Keep us updated. Hope this helps and thanks again for using 2CarPros.

Danny-