Heh, I've been fighting with this kind of problem for months with my '87 Ranger. If someone has bypassed the wire that goes from the fuel relay to the inertia switch it is probably because the plug that goes into the switch is fried, as mine is. If what I described is the case on your truck try unplugging the plug from the inertia switch and see it the truck runs any better, it helped me for a while. One thing I learned is that you must leave the wire running from the relay to the end of the inertia switch plug intact. I tried splicing a line directly from the fuel relay to the line that runs from the inertia plug to the fuel pumps. The pumps had no power. When I put the line I had cut (the one from the relay to the plug) back together the pumps worked again, even with the plug unplugged from the inertia switch. Just FYI, hope that wasn't too confusing...