Hey all,

So I have a 79 F250 4x4 with a newly rebuilt 300 in it, with a few upgrades. I'm not getting the mileage that I was expecting to get or should be getting from what I hear from other members who have similar trucks with the same upgrades on the 300 that I have. I've been told that the carb needs to be tuned and I'm not sure how to do it and don't have all the required equipment anyways. So I was wondering if anyone here knows of a good mechanic who can do a good job on doing a proper carb tune up, adjustments so that I can get it running better and get the MPG that I should be getting.

Thanks.

 

Finding a good carb shop can be hard these days.

Do you have a vacuum gauge? What type of carb is it so that if someone
does happen to know they can give you some pointers.

I sent a message off to someone that might be able to help.

 

Been a while since I've posted. I had some luck tuning my 4 barrel Carter on my '78 Bronco. I can't guarantee I can do it but I'd be willing to give it a try. Details on what kind of carb it is would be nice, the condition of said carb, the MPG you have and what you are shooting for, and approximately where you live in Olympia.

 

West Side of Oly. newly rebuilt 300, new carb, Edelbrock Performer 500, have the calibration kit with it, new Offy intake, EFI exhaust and new Crane 262 cam. 900 miles on new rebuild and hoping to get in the range of 15MPG which is what others that have the same basic, identical rebuild and set up are getting, I just want it tuned so I get what type of MPG I should be getting compared to others.

 

What are you getting now and have you taken into account a new tight engine?
One thing that a lot of people don't think of is fuel pressure. Too high and it
can get past the needle valve and over flow into the intake. That also goes for
a float level set wrong. Of am I missing something like is it an electronic carb?

 

The type of carb will affect it. A stock 2 BBL Ford carb would probably get you close. I've never worried too much about MPG since my '78 Bronco got around 4MPG for a long time. My guess is tuning it for the best Lean running condition is going to get you the best fuel mileage. Making sure there are no vacuum leaks, the choke is working properly, timing is set properly. I've never been great at getting things dialed in 100%, I normally shoot for smoothest running condition.

 

I have a tired 300 with many of the same parts, and a bigger cam. I have the fuel jetting on #6 of the calibration chart, plus the softest step up springs. Mine gets 14.5 tankful avg if I keep it under 70.

 

I can play with it if you like, live in Shelton and in Oly all the time.

Biggest MPG problem with any 300 is compression ratio (static CR), this problem is further exaggerated with a bigger cam (Dynamic CR). Did you increase the CR with the rebuild?

Edelbrocks are pretty simple.