I've been dealing with this issue for a while now, and I've finally had enough. I have a '78 F150 4speed, with recently built 400 (year and half ago). It has a recently rebuilt Edelbrock 1406 600cfm, New filter, new Holley fuel pressure regulator set at 5.5 psi, new fuel lines, new pump, new 40 gallon tank, with new sending unit, etc. The problem started well after all these items were installed. Truck was running great , then problem started out of the blue a few months ago. It acts starved for gas and takes many pumps before it fires. A couple times, it has taken several minutes before it starts. Always runs great once started. I have a 1" phenolic spacer, so I don't think the fuel is boiling out. Problem normally happens when completely cold, but not always. It sat for two days, and fired right up with one pump, then the very next day, I could not start it until I sprayed starting fluid in bowl. When I manually work the throttle linkage, fuel sprays out of the two diagonal nozzles at front of carb (can't remember name). These are the only nozzles where it is supposed to come out, right? Any ideas what the problem may be here? Always idles just fine once started. One more thing, the choke seems to be 3/4 shut until warm. Electric choke. Sorry for the long post, but wanted to make sure I gave all the info I could think that may help.

 

Have you checked the rubber fuel lines. They could be deteriorating internally from ethanol and becoming blocked or small particles of rubber are making their way to the carb needle valve.

 

Yes, all new fuel lines, hard and rubber. Plus, I run ethanol free gas. I've started about five different times today and aside from the first time, it has fired right up each time. I'm at a loss.

 

Whats your timing set at? The ford recommended setting is for sea level, sounds to me it good be a little too far advanced

 

I don't recall at the moment, but I believe it is 32 degrees. It has not been changed since well before the problem started though. I will try to check again soon.

 

It's important that you narrow down whether you think it is starving for fuel or it is being flooded by heat soak ..

Is the distributor the original duraspark II ?