Couple places around me. Don't know about the costs.

Specialized ECU Repair, Replacement, & Testing - Restore or Exchange your Electronic Control Unit (ECU)


https://www.autocomputerexchange.com

 

**UPDATE** I have found a known-good ECU. I repaired the area below the ECU to seal up any ingress of water/salt/sand/snow/slush etc etc etc. Installed the 'new' ECU and took it for a drive. High idle at first but as the ECU got talking to the various sensors it settled down. Now the super-fast idle seems to have settled down however the idle is still rough, with the revs hunting up and down, and a 'stuttering' feeling when driving. No CE light. Only one code P1171 Oxygen Sensor System Too Lean Fault Banks A & B
And the search goes on for more info...

 

if you havent already...
clean the whole intake and butterfly valve and maf - remove the crank case to intake hoses and spray the gunk out
replace with new both of those crank case to intake hoses
add a can of seafoam to a full tank
Check the coil packs - a hairline crack will cause arcing to the bracket which results in a misfire (usually bad when damp out or first starting in morning)

Im not an expert - this is just some of the stuff I have done
good luck

 

Thanks for that. I will now take the air intake off and look up the hole. I had a mechanic work on it for me and he said he cleaned the throttle body, but until I've checked it myself I will wonder. (I've already applied Seafoam to the tank)

 

I only had a rough idle issue after using 87 octane for 1 tank and then bac to 93- unplugged the batttery for 2 hrs and it settled down with in a few min of restart

Im really leaning toward the path from the coil pack to the spark as the issue from what you described and my experiences
try - at night - lift the hood and start the engine and see if you see a arc from the coil pack to a bracket or body or ground etc.....

 

Thanks whiskeynipple. I have it settled down at the moment - just now. I took the tube off the fuel pressure regulator because it was "sloppy" and cut the ends off, then re-fitted it. Seems to have helped a lot. There's still a little hesitancy so I will definitely look at spark related items. It has all new plugs but I'm going to order a set of decent leads shortly. The truck must have sat for quite a while before I adopted her so there will be a few issues to sort out. Idle is still a little high in my opinion but manageable. Oh, and I have been putting in higher octane fuel since I bought it.
I will keep plugging away...