if i let my truck sit over night it turns over for about 15 seconds before it will stumble start. but for the rest of the day it will start fine. any ideas what to look for? i have a pressure guage sitting on it tonight so that i can check it as i start in the morning. the only strange thing is my buddies truck is doing the same thing.

 

Turn the key on, wait about 7 Seconds, then start the truck.

Let the fuel pump make the 40 psi it needs to.

Try that.

 

Assuming you have a modern fuel injected engine,

Often this symptom tells you the anti reverse flow valve(not sure of technical name) is going bad on you.

When the valve is working correctly it prevents the fuel from bleeding back into the gas tank too soon. It keeps the pressure up in the fuel rails enough that when you start the engine the next day, it should fire right up.

If you have to crank it awhile or crank stop wait crank again, then probably the valve is getting sticky and bleeding off pressure too quickly.

On my wife's van the valve is inside the tank. Some tanks you can pull it out thru an access hatch. Some require dropping the tank. Don't know on a Ford truck since I haven't had that problem.

With a carb this problem is usually the fuel bowl is leaking or the engine is so hot it boils off the gas in the bowl.

Good Luck,

Jim Henderson

 

looks like it was the Schrader valve on the fuel rail replaced it and it has been ok since.