Please, please...try to use it if you can! The carb has a fuel and vapour bleed back facility, and it eliminates all hot fuel handling problems. If you block it off, it'll run rich, and it won't work as well. The great fuel economy streams from the working float level and fuel pressure being very low. The stock pump has over 6 psi of pressure, while the 50 thou bleadback restrictor reduces it to under 2 psi at times. Cool fuel is then always being circulated.
The pump is the same US Carter piece as the US 250 underneath.
The bleed back line is just like the one used on 1983 onwards carby 4-bbl 5.0 and 5.8 Mustangs and F150's.
To plumb a line is a pain, but Ford Oz, in all its wisdom, followed the US carby V8 practice.
Choice is yours.
Most guys think, hey, I'll just rip this darn junk off, and life will be sweet. Having done an '83 Alloy Head II 2-BBL Weber swap to my mates old '82 1-bbl Alloy Head ute without a return line, the Weber ADM 34 leaked like a sieve, ran rich, and suffered flooding problems.
The ute had no return line, and I had to grab some brake line, and re-run it to copy the stock '83 Ute.
The tanks used in post 1968 Cali or post 1972 Mustangs had an evaporative junction which you may be able to fit if you find it hard.
Anyone else here done it?
*I notice with interest Ford America used the very early non return line Holley Weber 5200 2-bbl. Aussies and Kiwis had similar non return line Webers on early 2.0 Pinto engined Cortinas. The early ones flooded and leaked and were thristy, the later ones with return lines were were much better. There was a serious recall issue. It's an issue with Weber carbs which, but the Pinto was already subject to under bonnet fire issues, so perhaps the American 2-bbls were engineered better.
Very last option would be to block off the return line, and fit a pressure regulator only. Not a good idea.
.I have had heaps of fuel related problems with my car when running a holley 2 or 4 barrell . Ive never checked on fuel pressure but have allways wondered if the new pump was a sorce of the worries. My first rebuilt engine suffered from bore wash from a over fueling carb .Im going to start my reringed rebuilt :x engine soon ,so ive got my hands on a z102k fuel filter.When i can lay my hands on a fuel pressure gauge ,i will do a before and after pressure check .Whats the correct fuel pressure on a 4 barrell holley supposed to be ? and X whats the go with running fuel pressure reg with out the return line ,does this put stress on the pump diaphragm ?
