Fuel pump fitting

[sickquad]

Can anyone tell me what the size of the fitting is coming out of the stock fuel pump.

I'm trying to get an old motor running and I cannot figure out what the fitting size is. The previous owner of the motor was a major hack so they could just be screwed up, but from what I see they look good.. I've tried every possible thread size and I cannot get anything to catch more than a half thread.

-Chris /forums/images/graemlins/dunno.gif

 

[Can Can]

Is there a chance you're using fine threads on a coarse threaded fitting, or vice-versa?

 

[sickquad]

No, they look like they should fit, definitely not mismatching threads.

I just looked at the pump on my truck and they are different. I know mine is a stock replacement, so maybe the reason I am having problems is because this thing is aftermarket? Are there metric pipe threads or something?

-Chris

 

[diesel4me]

If you mean the fuel pump for a carbed engine,nearly every one I have dealt with had 5/16 or 3/8 female inverted flare fittings(threads would be 1/2x20 for 5/16,9/16-18 for the 3/8)--so regular brake/fuel lines should go right in--if its an aftermarket pump,it might be metric,or even pipe thread--but I've never run into one (yet!).If its EFI,you got me- /forums/images/graemlins/dunno.gif-I'm still driving carburated vehicles--too new for me!. /forums/images/graemlins/crazy.gif