Conversation Between klricks and Eurocomsteve

Hello,
Saw your helpful posts about 1986 fuel systems. I replaced my DFR last night. Guess I should have checked fuel flow from both supply lines before I finished because afterwards I still had overflow from the front tank filler hose after the truck ran for a few minutes. Typical symptoms of front tank pulling from rear tank. I did run off the rear tank after putting $20 bucks of fuel in it a week ago and it ran fine but you could almost watch the gauge going down. I assume after replacing the DFR I have a bad or weak pump but based on my description of the symptoms, which tank do you think has the bad pump (front or rear)? Just wanted to ask to see if you had a suggestion before I went out into the cold again to get covered in fuel again from doing the flow test. Thanks in advance.