My '85 F150 is not starting. It has been parked over a year and was running a couple of days ago. It did keep dying but only going downhill, and it always started again after a few minutes parked by the side of the road. This time it didn't. It will turn over all day but won't catch even with starter fluid. I've replaced the fuel filter, the fuel pump (in the frame) and the distributor cap and rotor. I have blue spark to the plugs. I have pressure in the fuel rails. Why won't this thing run? What is the relevance of it only dying going downhill? It drove around town and uphill without a hiccup. Thinking it may be the in-tank fuel pump I switched tanks, still no go. I don't think it's likely that both in-tank pick-ups are bad. I need to get this thing running so I can get a job, please help. Thank you in advance.

Cars & Trucks - Ford - F-150 - 1985 Ford F150