So i got a 79 f150 with a 400 and it does a few weird things that kinda bug me. First off its hesitates a lot of the time when taking off. Like not enough fuel-too much air. You gotta pedal it a time or two for it to kick in. Then its fine. Of course it does it when its cold, because that's expected, but even completely warmed up or around 175-185. Its got a 192 thermostat in it so it isn't cold by any means. I'm just wondering how you fix sometime like that? I have a fuel pressure regulator on it and it has a very fine line. If the pressure is too high it will overflow the float bowl, then pour over the top into the carb, thus flooding it. If there isn't enough, it hesitates because of not enough fuel. I'm on that fine line right now. If i increase the pressure anymore, it will start to overflow if sitting at an idle for too long. Thats one issue. The other one isn't as bothering but i'm just kinda curious. I'm in central oregon and the winters are cold at night. I don't have a block heater or anything so the motor gets just as cold. So when i got to start it in the mornings, if i just turn it over, it'll fire, run for 2 or 3 seconds then rpm's go down and it dies. Even giving it gas, you gotta pedal it and keep it alive for maybe 20-30 seconds. Enough to where it will run on its own. Then i turn it off, then start it again with the choke on. I'm just wondering if that's a normal thing or if it has anything to do with my hesitation problem. Thanks in advanced guys!

 

With the hesitation issue, I'd start with the basics. How many miles are on the spark plugs, are they oil fouled, timing, distributor cap, and rotor all nice, and are they burnt. Fuel filter ancient, plug wires good. The basics go a long ways.

Unk Bob

 

Not normal. I pump my 74 390 three times and it fires up and runs on its own, no touching the gas pedal.

If your carb is overflowing and flooding that easily, my guess would be the float height is set wrong and/or the needle and seat is damaged or installed incorrectly.

 

I'm only 17 and my school is 5 miles away, and everything is exceptionally new. Under 1,000 for sure. During the summer i never have to pump the gas to start it, even in the mornings and it worked that way near the beginning of the winter so it is more than likely a weather issue. But minor parts wise, they're all pretty fresh. Except for the cap and rotor. They're MSD so i've never really worried about it but it's about a year and a half old. The truck is really fresh and i never drive far so it doesn't get any insane milage on them.

 

One of your cold start issues is probably your oil is too heavy of viscosity, my father lives where you do, and he runs light oil in the winters so his diesel pickups will start. You may want to ask around at the part stores what some of the old timers put in their rigs during winter (weight oil).

And you need to do some carb tuning it sounds like....your hesitation could be your accelerator pump improperly adjusted or doesn't work on the carb, OR your vacuum advance on your dizzy isn't working.

 

It's a MSD dizzy without a vacuum advance. So maybe it's the accelerator pump. It's a brand new carb and i haven't done much tuning on it so how would you adjust it or check it?