AMC FACTORY FUEL RETURN LINE

[JERSEYJOE]

I know that the factory put these fuel retun lines in all AMC products, but are they really needed? I assume that they are supposed to bleed off excessive fuel pressure to prevent a fuel boil over on hot days. Is there anyone not running one? What ill effects do I risk if I omit it?

[tufcj]

It's mostly to help prevent vapor lock. I had a lot of problems with vapor lock on my Jeep when the return hose kinked at the filter. I replaced the bend with a piece of hard line and my problem went away.

My 69 AMX has no return line, I have no problems, but it was built that way.

I think there's really almost nothing to gain (2 lb weight savings?) from removing it, and possible problems to be created. I'd just leave it be.

Bob
tufcj

[rollen dean montoya]

better leave it in. never had any problems in the eagle.

[JERSEYJOE]

Well for starters I was not going to use the small stock filter. I was going to use the Fram cartridge style big one. I went through the trouble of bending up all new lines from the tank up front but to remove one line would not break my heart. This is not really a street going Jeep. Did not know that the 69's had no return line. If I was going to re-plumb it back in where should it go? anyplace after the pump before the carb inlet?

With a constant return line how does this NOT reduce fuel pressure? Seems like it's a constant pressure bleed off.

[ironman_gq]

should work as long as its after the pump but you might be able to get away without it

[tufcj]

The factory return line on my CJ was 1/4" , not enough to move a huge volume of fuel, so I doubt pressure suffered. Factory feed was 5/16". I used a Carter high volume mechanical pump and had a regulator holding 6 PSI at the carb.

With my EFI, feed is 3/8" and return is 5/16", the pump (electric) still holds 16 PSI.

The return could be plumbed anywhere between the pump and carb. I'd put it after the filter just to make sure any fuel going back to the tank is filtered.

Bob
tufcj