Fuel pump relay won't stay closed / open

[wisconsin5.0]

First time posting here. so here goes...
I'm in a 97 XLT awd 5.0. 242,000 k!
Ran great until a month ago. Started having intermittent issues running. Basically the Main issue is that the fuel pump relay circuit will not stay closed. I've traced this back to the ECU not fully keeping the supply open. The result thus far is the pump relay clicks repeatedly like it's being cycled on and of in half second intervals.
I have checked Cps, Cms, tps, MAF, as well as all grounds to and from PCM, and Fuse panel. The weird part is occasionally it's will stop clicking and I can fire it up but it will take off clicking again eventually starve the engine out. I also have bypassed the relay system to keep the pump on but if I do this the ECU is not supplying the spark at the same time. It seems like the ECU is not "ready" to start with whatever condition is present. I'm about ready to try another ECU and see if there is a resistor or something that's faulty.

The motor and trans are in great running condition and I love driving my truck. I makes me sad that this electrical issue is keeping me from driving it. As far as I've seen there is no way for me to bypass the ECU and simply run a carb and distributor without removing the trans, etc.
I'd like some in put on anything I may have missed as well as if any one has had this same issue. I haven't run acrossed it yet and iv'e been searching the net for a while on this issue.
Thanks!
-Wisconsin5.0-

 

[Turdle]

Let's try something simple.

It could be as simple as intermittent connection in the PCM relay --have you tried swapping them around? Another trick is to slightly twist the prongs of the relay so it bites in tighter.

 

[wisconsin5.0]

Yup did all of the Basics, swapped relays etc. There is correct voltage and ground all over. When it's "clicking" every other sensor / relay has power from / to the ECU.

 

[wisconsin5.0]

Also, the OBD shows a "fuel system circuit fault" (no **** lol)
Is there a fuel pressure signal possibly? I know there is pressure but I just thought if it is acting like it's not fully pressurized so it turns back on then off??

 

[wisconsin5.0]

Update:

Replaced PCM as stated in another post here, and BINGO! Haven't had any re-occurrence of my issues.

Thanks to all for filling this forum with such useful information. I am a typical hard working middle class man and my wife also busts her butt too to provide for our family. This type of resource has helped me save money as we all know every little bit helps. I have had my explorer for 9 years and purchased it for 1200 dollars with 140000 miles on her. Glad to say after a little love and wrenching, and 100000 more miles, she will once again be road bound!