Hesitation and back fire

Posted by Paul E. Gallagher On 2023/8/23 18:15:38

I recently added an electric fuel pump just for cold starts. The Packard gurus said to add a check valve which I bought but never installed. This would avoid drawing the fuel through the electric pump when it was off. The pump is exactly what the gurus recommended, Airtex, 6 volts, etc..

When I run the car at freeway speeds (50-55) after about a half hour of travel, the car starts to hesitate and back fire. When I turn on the electric pump, it smooths out. I’m not sure if this happens in regard to speed or the time the engine is running.

When I came home Saturday, I had the electric pump running and it was leaking gas from the mechanical pump. I checked it running with the electric pump on and with the engine off and gas was coming from the mechanical pump.

Do I need to replace the mechanical pump?
Would adding the check valve help?
Is something wrong with the electric pump?
The electric pump did not seem to help much with cold starts.

Any ideas on what to do next?
Thanks in advance, you people are the best!