Rocky_JS
'cuda
I have the factory 4294s AFB on my car and have been doing a fair amount of driving and getting poor fuel mileage.
A week ago I went on a trip to the coast about 125 miles one way. I started to check the mileage. I was getting 9.4 mpg highway and city. my friend I was following got nearly 19MPG also 67 Barracuda stock 273 commando 4-speed car 3.23 gear but with Holley carb.
I have also been fighting a initial part throttle flat spot which clears right up. Yesterday I took the metering rods out and checked them against my book which calls for a factory 16-403 3-step rod.
The best I could find on the net was only 2 of the 3 steps this rod should have at 0.0690x.0650.
The ones in the car were 16-547 which I mic'ed at .0650X.0610x.0520. the only other 3 step rods I have are 16-404 0.063/0.060/0.051 which would be even richer.
I have a 1405 Eddie sitting around. So I took the stock 2-step metering rods .070x.047 and the flat caps off the eddie and stuck them on the Carter.
The flat spot and low speed chugging is gone. I drove about 50 miles at highway speeds and MPG improved to 13.8!
The main problem I have is one of the jets is stripped out so I am unable to change to the low jet. Finding 3-step rods isn't easy. The 2-steps are readily available in many sizes to better calibrate.
What are the implications with using the high jet on a 2-step metering rod system?
I measured the rods and they seem to be the same length, but the steps are in different locations. Seems that the rods will not raise enough to get to power mode?
Conversely, I could see using a low jet, 2-step rod with a dimple cap allowing the rod to come out of the jet and be real rich in power mode.
Sorry this is long winded, but after searching the net all day yesterday I could not find a clear answer.
A week ago I went on a trip to the coast about 125 miles one way. I started to check the mileage. I was getting 9.4 mpg highway and city. my friend I was following got nearly 19MPG also 67 Barracuda stock 273 commando 4-speed car 3.23 gear but with Holley carb.
I have also been fighting a initial part throttle flat spot which clears right up. Yesterday I took the metering rods out and checked them against my book which calls for a factory 16-403 3-step rod.
The best I could find on the net was only 2 of the 3 steps this rod should have at 0.0690x.0650.
The ones in the car were 16-547 which I mic'ed at .0650X.0610x.0520. the only other 3 step rods I have are 16-404 0.063/0.060/0.051 which would be even richer.
I have a 1405 Eddie sitting around. So I took the stock 2-step metering rods .070x.047 and the flat caps off the eddie and stuck them on the Carter.
The flat spot and low speed chugging is gone. I drove about 50 miles at highway speeds and MPG improved to 13.8!
The main problem I have is one of the jets is stripped out so I am unable to change to the low jet. Finding 3-step rods isn't easy. The 2-steps are readily available in many sizes to better calibrate.
What are the implications with using the high jet on a 2-step metering rod system?
I measured the rods and they seem to be the same length, but the steps are in different locations. Seems that the rods will not raise enough to get to power mode?
Conversely, I could see using a low jet, 2-step rod with a dimple cap allowing the rod to come out of the jet and be real rich in power mode.
Sorry this is long winded, but after searching the net all day yesterday I could not find a clear answer.
