This is a copied post. i just wanted to make sure i was putting in the right forum so i posted it two different places on here. I have a 1994 F150 XLT with a 300 CID 4.9L 5 speed manual transmission. (single tank)....i had forgotten to update my old post on the forum. i had gotten the truck running and driving after finding faulty spout wiring. So that was nice. But it was short lived. this past weekend it started high idling and throwing code 411. i was trying to get back home when it stalled out and died going down the road. it came back to life and i drove it home. Replaced the idle air control valve and it still did it. As i had it sitting there idling checking for vacuum leaks it dropped to about 400 RPM's and then down to 200 back up to 1100 and then stalled out and died. Giving it gas didn't help. Couldnt get it to crank back up so i threw the code reader back on it for A KOEO test and got codes 542 (open Fuel Pump Circuit PCM to Motor) and the TPS out of range code. Can't remember the number off the top of my head. I verified the TPS was out of range and replaced it but the truck wouldn't crank back up. I started checking all my connections for the fuel pump and its grounds found no bad connections. I made sure the pump was turning on momentarily when the key was turned on and it does. i am getting good fuel pressure at the valve. I cleared the PCM codes and the system passed. i then checked all 6 plugs found they were fouled so i put new plugs in it and still no crank. I checked spark from the coil and its good. i then checked spark from to the plugs and its good. I can spray starting fluid into the throttle body and it will come to life until it runs out of fluid. I'm kind of stumped here and need some help as i need it to pull a trailer and boat this weekend.Here is a list of parts I've put on the truck since October 2015

PCM
Ignition Control Module ( Correct color ) Black Fender Mounted
EGR Valve
EGR Solenoid
Spout Sensor ( Did the timing with the spout out ) 10 degrees BTDC
All new gaskets and vacuum hoses.
Distributor
Distributor cap and rotor
Plug wires
Spark Plugs
Fuel Pump
Fuel Pump wiring harness
Fuel Filter
Fuel Pump Fuse
Fuel Pump Relay
Coolant Temperature Sensor
Idle Air Control Valve
Throttle Position Sensor
Check Compression all 6 of my cylinders are at 150 PSI
I have cleaned and rebuilt the injectors with the rebuild kits. they all Ohmed out good.
Mass air flow sensor checks out good
Fuel Pressure regulator does not smell like fuel nor is there fuel in the vacuum line i believe that means its good correct?
I think that's everything. Thanks in advanced for all the help!

 

Anyway to check fuel pressure at the rail?

Maybe the Fuel Pressure Regulator is faulty or blocked... Is what I'm thinking.

I'm stabbing in the dark, and don't really know ford's pcm efi's.

Do you hear the fuel pump do the prime cycle when Ignition Key is first turned to "On"? Do this with a fuel pressure gauge attached at the fuel rail. AKAIK, Ford 300's run a higher pressure than the V8's and can't remember that value right now.

 

I had an odd and difficult problem just like yours and eventually found it to be the magnetic coil was loose on the pickup inside the distributor. This small coil is encapsulated in plastic and is mounted to be picking up the signal from the reluctor. It was loose and would move around so much it would sporadically alter the timing enough that the truck wouldn't start or run.