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1994 7.3 Powerstroke 5 speed Manual
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Discussion Starter · #1 ·
I have a 94 Powerstroke 7.3 and I have recently done a fuel bowl delete as well as installed an electric fuel pump. At idle the fuel pressure is over 60-65 psi, after driving approximately a mile the truck dies due to lack of fuel pressure. I can immediately turn the key to the on position and it builds up fuel pressure and starts right back up and is good for approximately another mile or so. There are no obvious leaks in the fuel system. When parked overnight the truck had 20 psi on the fuel system and this morning I checked and it still had 20 psi on the gauge about 12 hours holding pressure. Any ideas of what could be causing this loss of pressure when running??
 

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1994 7.3 Powerstroke 5 speed Manual
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4 Posts
Discussion Starter · #3 ·
Check if the electric pump is running and if it is installed backwards.
Did that initially because it didn’t start after installation, it was backwards and we reversed it and it cranked right up. On the test drive we got about a mile before the first time it died, etc.
Today we verified that the supply and return line were correct by disconnecting the lines at the switch and blowing them out with an air compressor.
My thoughts are possibly a dead rail ??
 

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1994 7.3 Powerstroke 5 speed Manual
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4 Posts
Discussion Starter · #4 ·
Mystery solved. Turns out that electrical connections were not proper, the pump would run and basically shut off shortly after we started our test drive. At the start of the drive we had 65-75 psi, as soon as the pump stopped running we were basically running until the fuel pressure hit 0 psi and die. As soon as I cranked it back up the pump kicked on and built the pressure back up and start right up. Relocated the pump power to the proper fuse and no more problems.
 
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