I have an interesting problem that I can't seem to solve.

When I start my truck ('87 F150, 5.8L 351w, carburated) in the morning this is what happens.

Turn key to on
Pump gas peddle 2 1/2 times, holding at about the 1/2 way point
Turn key to start
Engine starts, then dies about 1-2 seconds later.

Turn key off, then back to on
Pump gas peddled 2 more time
Turn key to start
Engine cranks, backfires, then starts while I pump the gas peddle.

This happens every morning, and some days if I don't start the truck after is sits for 8hrs or so. I thought maybe since I parked on a slight incline the gas was draining from the gas line back into the tank, letting the carb run dry after it is first start. I parked a couple of nights backed in the driveway and I had the same results.

Any suggestions?
Thanks in advance

Ryan

 

Check your choke linkage for binding, also check and make sure that the fast idle cam is falling into place when you first pump the pedal. To do this open the hood when the engine is cold and activate the throttle by hand after removing the air filter. The choke plate should close and the fast idle cam should fall into place holding open the throttle slightly. DO NOT ATTEMPT TO START WITHOUT THE AIR FILTER, with the engine back firing and no air filter you could end up burning the truck to the ground.

 

sounds to me like there might be a small pinhole leak somewhere allowing th egas to flow back down the line but I could very easily be wrong on this

 

Carbureted vehicles are such a pain to start in the cold. I'd have to say a choke problem too. Here's how I start my carbureted vehicles, and one doesn't have a choke but it still works: Pump the pedal to the floor three times, try to start the truck. If it doesn't start then stop cranking and pump the pedal three times again and try again. I repeat the process until the vehicle starts, but if it runs for a few seconds then stalls then you need to stop the pumping and just try to start it again. When it starts again you give it light gas to keep it going. Each vehicle will have slight variations in the final starting process but the pumping three times in the beginning works well for me.