Hello this is my first time posting anything but I have one that is really driving me crazy. I recently bought a 90 ford f-350 7.3 idi non turbo. When I purchased it the truck was sitting for about six months. I got it fairly cheap for the condition it was in so I didn't question the fact that we had to spray wd-40 in the intake to get it started. So I drove it home a little over a 100 miles with no problems. I noticed the next day when I went out to the truck that it would not start up on its own. Once again I had to spray the wd-40 and got it going. So this is what I came up with I replaced the fuel filter and have plenty of flo going out of the filter and into the ip but I have a extremely small amount coming out when trying to crank it. I have checked the fss and it does have power. I believe it is ether going to be the mechanical pump not pushing the fuel hard enough to make it threw the ip when trying to crank it or the ip is bad. PLEASE HELP! Thanks

 

Need to ensure the power is getting to the IP Fuel shut down solenoid .. that will cause that issue ..

 

Where is the solenoid located for the fuel shut off

 

There are two plugs on the top of the IP .. I am not too sure wich one is which .. mine was only able to be pluggen in one way ..

 

if no current check the 20 amp fuse under the hood. Do you get the clicking when you turn the key on? If not it is the big 20 amp under the hood! If you can get some one to turn the key to the on position you should hear a click from the pump each time the key is turn on or off that is the valve relay functioning.

 

I would bypass the fuse with a power probe or a jump wire with a 20 fuse in it ..

 

Check all your fitting and make sure you bled the fuel system. The mechanical pump only puts out 5 to 8 psi You could try to disconnect the output line from the filter and hold your thumb over it and have someone crank the engine for about 30 seconds or so then after they stop cranking hold your thumb for a few seconds. Then remove your thumb you should hears a slight hiss followed by the fuel. If you do not then two possibilities small hole in the diaphragm or a hole in the fuel line. You can also check the output of the mechanical pump put a small bottle or some thing to catch the fuel I have used a 4oz bottle that was empty and Just crank it a few second and it should pretty well fill the bottle up. These are back yard methods but it beat paying $50+ to have someone hook all the fancy gauges up to tell you the pump is fine! If it is the IP be prepared for sticker shock $800+ for rebuilt one!

 

Also make sure when your trying to prime the IP .. foot to floor while cranking !!!