Okay so I just bought a 1992 F-150 with a 4.9 strait six auto tyranny 2-wd. Here are the problem's'
It just randomly shuts off. It shuts off while in park, going down the road while lightly pressing the accelerator, and after you stop at a light and even just by a hair hit the accelerator.... boom it dies. Yes every time it starts back up and keeps on going, till you stop then hit the accelorator and again it dies.

What have I replaced? I have replaced the
Spark plugs
Spark plug wires
Distributor cap
Rotor
Distributor
Throttle position sensor
Map sensor
Harmonic balancer
Ignition control module
Ignition coil
Egr valve
Idle air bypass valve
And fuel filter.

I did check the fuel tank to see if it was rusted, and its super clean. The fuel pump is pure white (looks new) and when I replaced the distributor the 1st time, it seemed to fix it. And the next day it does it some more. I can adjust the distributor and it fixes it till I turn the truck off. I also checked the fuel pressure and its at about 44-46psi with no drops

So I'm super stumped, and no one can tell me what it is. Any help beyond what I know is absolutely better than anything at this point.

 

Fuel pressure should be 50-60 PSI KOEO.

 

So what would cause it to be low?

 

Where did you check the pressure, before or after the pressure regulator? If after the pressure regulator could be bad (weak), if before it could be the pump or a bad fuel line.

 

I'm not sure. There is a nipple on there injection rail on the back of the motor and that's where I checked

 

I think that was after the pressure regulator. Mine has a carb. so I cannot tell you where it is located. Should be able to follow the fuel line to it from the filter I think, If memory is correct it should be pump, filter, pressure regulator, then fuel rail, then return to tank, or the return could be on the regulator I am not sure about that point. Hope this helps.

 

Well i did talk to my mechanic and he said it had to be the ecm? Is that possible with these symptoms and also, is there a way for me to check the fuel pressure regulator?

 

Sorry I do not know the answer to these questions. As to the Engine Control Module my question to you mechanic is how it is related to the problem? I do not know enough to answer the question so.. Wish I knew more about your fuel system to help more.

 

What all do you need to know? I have learned quite a bit about my truck in the past 2 weeks trying to fix it

 

it may not matter or be an issue for your truck, but i have a 93 5.0 and my truck had a recall for the fuel pressure regulator (im pretty sure thats what it was) but you may wanna call your dealer or look up online to see if your truck had the same recall. they'll be able to tell you if the recall work was ever done, and if not they'll fix it for free. again, since you have the 4.9, im not sure this will help or not