My son has a 1999 Ford Ranger with a 4 liter V6 cylinder. The engine has gone bad, and are trying to replace the engine from a 1995 Ford Explorer, also with a 4 liter V6 cylinder. We have both engines pulled out, but I am confused by the fact that the Ford Ranger does NOT have a return-fuel-line. I thought all fuel-injection engines had a return-fuel-line. Can someone please educate me on this matter. The two engines look almost identical, but I'm not sure what I should do about this fuel-line issue since the engine being used expects a return-fuel-line, but the ranger does not have it. What are my options?