Please Help! Can't start my 76 F150
 

So here's the story...I bought a 76 F150 about 3 years ago in Tucson AZ, with the dream of doing a light restore/driver fix-up on it. I drove the truck as a daily driver, doing repairs on weekends for a year and a half. The truck ran great when I parked it in a storage facility in Tucson. I moved back to Upstate NY for work about 18 months ago, and had the truck shipped to me on a carrier.(rust free classics are impossible to find in snow country, so it was worth the transport fees.) When the truck was delivered about 2 months ago, I took it for a drive around the neighborhood and it still ran the way I remembered. I haven't done anything with it until now, and I finally have tags on it again and want to drive it/continue restoration work. When I try to start it, it cranks, and will fire a couple of times but then dies. I have spark from the coil, and the cap/rotor/plugs/wires are new and dry. Battery is also new. Thinking that the mechanical fuel pump has lost prime, and the carb bowls are dry that gas must have evaporated during sitting time. So, I put some gas (about 6 ounces) in carb, manually operated the throttle, and tried to start it again. This time it fired a few more times, but then backfired through the carb, and started a fire in the carb. After putting the fire out, and letting it sit for a few minutes, I tried cranking it again and it backfired loudly through the exhaust. I disconnected the fuel line at the carb, and put the hose in an empty bottle. I tried cranking the engine to operate the fuel pump, and got only a couple drops of gas. I then removed the inline fuel filter (between tanks and pump), and noticed there was barely any gas in the lines or filter either. I poured some gas through the filter and it flowed pretty well. So I am thinking that the mechanical fuel pump is not working. Thoughts? I did have the ignition control module bench tested at Advance Auto Parts, and it tested good 3 times. I also tried fresh gas in both tanks, and tried starting with both tanks switched on to rule out an obstruction in one of the tanks. I would like to try to figure this out without dumping a bunch of money into parts/labor at a shop. The truck has a 390 which was rebuilt by the previous owner, and bored 20 over. The engine has less than 30k on it since the rebuild. I put a new Edelbrock 600cfm carb on it back in Tucson, and it has been tuned without changing any settings since. The truck is the Camper special with the dual fuel tanks, and the selector switch on the blower control panel. Any help would be greatly appreciated. Thanks - James

Is the rotor turning when you crank the engine? I'm assuming so since you're getting spark (which means the distributor is turning), but are you still getting spark? A bad fuel pump wouldn't explain backfiring out both the intake and the exhaust. That almost sounds like some kind of timing issue. The reason I asked if the rotor is turning is because the fuel pump isn't pushing fuel through (which makes you wonder if the cam is turning). If that were the only issue then I would suspect the fuel pump, but the backfiring almost makes it sound like something with the timing chain.

It wouldn't hurt to pull the #1 plug and feel when the #1 cylinder is coming up as you crank over by hand, center the engine at TDC and then make sure the rotor is pointing at 1 o'clock.

The raw fuel he dumped in could explain the backfires imo. First stop for me would be the parts store to pick up a new fuel pump. Theyre cheap, and relatively easy to change. Also, after sitting for prolonged periods, the diaphram dries out and tears/ gets a hole, etc.

Other things to check would be all rubber line pre-fuel pump. On top of each tank there is a rubber line from the tank to the hard line along the frame. and IIRC there is also a rubber "splice" between two hard lines along the frame. The latter was a problem i faught forever. Truck would run great for a few minutes up to hours then it would just randomly die and there would be no fuel. Turns out the "splice" (which was factory on mine) had split and was sucking air.

I've got nothin to add, you said it all. :-jammin