I have a 91 f250 with just over 78,000 miles on it. I cannot get it to start. I have fuel at the fuel rail and if i spray starting fluid into intake it will briefly start, but other then that it makes no attempt to run. I feel as if the injectors are not opening???

 

Def injectors. There is a tool to test them. My old Mustang had this same exact issue. It only takes the loss of 2 injectors to cause this. So you have at least two out. Must be a Ford thing.

 

here is a list to help you figure out what is wrong...

1 Clear out a possible flooded engine. If you have cranked the engine twice and your truck hasn't started, press the accelerator to the floor and turn the key to the start position. By pressing the accelerator, you will shut off the fuel supply and this will clear out any excess fuel if your F-Series is flooded.

2 Check the gas. Adding a few gallons. If there is an electrical issue with either the fuel gauge on the dashboard or in the sending unit, you will get a false reading on the fuel gauge though the tank may actually be empty. Attempt to start your F-Series again once you have added fuel. If you have actually run out of fuel, you will need to cycle the ignition between the on and off position a few times to allow the fuel pump enough time to get fuel to the engine. Also, you will need to crank the engine for a longer period of time after running out of fuel than you would during normal start-ups.

3 Reset the fuel pump shut-off switch, especially if the truck has received a sudden jolt, such as during an accident. This is one of the safety features of the F-Series to prevent a fuel spill or fire during accidents. To access the switch, open the passenger door and take off the access panel. With the ignition in the off position, press the reset button on the switch. Attempt to restart your F-Series.

4 Check the connections on the battery terminals to make sure you have a good, solid connection. Tighten the terminals with an adjustable wrench if necessary. If there is excessive corrosion on the terminals, clean it off with a wire brush and try to start your truck again.

5 Use a spark plug wrench to remove all eight spark plugs, one at a time, and inspect the tips. A spark plug that's dirty or has a broken tip will not provide enough spark to ignite the fuel in the combustion chamber. If necessary, replace the spark plugs. Ford recommends replacing the spark plugs every 100,000 miles.

6 Change the fuel filter to ensure you are getting adequate fuel pressure. Ford recommends changing the fuel filter every 30,000 miles.