1991 idi 7.3 fuel problem return lines

[kevin phillips]

Have a 1991 f-250 with a idi non turbo 7.3 liter that keeps blowing the fuel return lines off. I have tried blowing air through the return line to tank and it is free and not clogged up. I have replaced the caps and lines still doing it usually when under load is when it happens or high rpm. Replaced clamps with worm gear style then it split a line  so it seems to be getting excessive pressure in the return system. Any ideas or areas u guys have seen cause this? thanks for any replys 

[Bruce Amacker]

Twin tank with switching valve?  I've seen the switching valve on those trucks cause weird things. See if the guy is using it, or bypass it for a test......

 

[Brad Clayton]

This guy was having a similar issue.

 

http://www.thedieselstop.com/forums/f31/blowing-return-lines-melted-injector-258776/

[kevin phillips]

It does have the dual tanks with the switching valve. Truck has been sitting awhile also like a year or so just put back in use

[kevin phillips]

I bypassed the switching valve problem went away. M

[kevin phillips]

T he valve was not switching completly making return flow have issues

[Brad Clayton]

 Excellent, I'll have to remember that one for sure.

[Bruce Amacker]

 Excellent, I'll have to remember that one for sure.

Yea, right, like you're ever gonna see this again.....  

 

[Brad Clayton]