maineford

Greetings, I am the happy new owner of a '78 F150. The truck runs great "at speed" but is stumbling and sputtery at idle and acceleration from a stop. My mechanic recommends a carb/intake replacement and upgrade rather than rebuild (current set up is stock, 40 years old) to a Holley 500 cfm and aluminum intake. So, as a newbie, I call on your collective wisdom for the "best bang for the buck" way to go, and for any suggestions for "while you're in there." Many thanks for your time and expertise. Larry

djfllmn

iTrader: (1)

when you say it stumbles and sputtering at idle, does it clear up if you give it gas or does that make it worse? It could be as simple as the carb just needs adjusted(which is becoming a lost art). Or does it cut out on you when you try to accelerate. My 68 t-bird did that and it was resolved with just a carb replacement.

maineford

Thanks for suggestion. When I slowly accelerate,say, from a stop sign, I have to "feather", or go very easy, on the gas pedal--if I go with "normal, steady" pressure it can stall and stumble. After truck gets going though runs fine, no stumbling when going from 40 to 50 to 60, etc. Previous owner thought maybe getting too much gas (?) but after tinkering couldn't fix the problem. Larry

What adjustments should I make before going the replacement route?

djfllmn

iTrader: (1)

that sounds EXACTLY like my tbird with the old 45 year old carb still on it. had to feather it from a stop. The accelerator pump / power valve was junk. I would put a new carb on it, intake if you want to but its not necessary. If its stumbling like that you can't really tune it out with the mixture screws(believe me i tried), a new carb should get you fixed up

maineford

Great, I will try the adjustments first. What carb/intake do you recommend? Or just the carb on stock intake? My mechanic says Holley 500 cfm. Thanks again, larry

djfllmn

iTrader: (1)

well the first thing you should try to do is find out what carb is on there now and find what CFM that flows