Cranks but no start - PCM fuse keeps blowing

[Sweersa]

I have a final (hopefully) update to this issue. (Been over ten years!) Posting as it may help others who come across this thread.
My Ranger in hot weather continued to have the horrible, what felt like tranny slamming condition when going over bumps in the road. It hadn't stranded me again like it did when it died and continued to blow the 30 amp fuse, but it was becoming an issue, especially on the highway as the truck would slow down 5-7 MPH when regaining itself after the temporary loss of power.
The check engine light would come on briefly during some of these incidents. The best way out of this condition was to let off the gas, and it seemed to go back into gear until the next time it happened, which could have been a mile or less down the road, or days later if it was summer. I had my Ranger in the shop recently for some other issues, and they replaced my catalytic converter and muffler, and one O2 sensor.
I have driven my Ranger for a few months since in some VERY hot weather, over many bumps, and this issue hasn't returned. I think it's safe to say it's gone. I'm not sure what it was, but after those three items were replaced, it's been running and driving great. I notice better and faster acceleration too. For years, depending on the length of the highway entrance ramp, I could only get the Ranger to 55-60 MPH before having to merge onto the highway, which of course can be a hazard, even though it meets (barely) the minimum highway speed in my state. Now, I can easily merge at about 65 MPH if I put the petal down.
Maybe the old cat was heating up the transmission, and when going over rough road, it caused it to slip/slam? I wish I knew, but seeing how the issue hasn't returned, I'm happy with that. It never happened in colder weather. Maybe it had something to do with the O2 sensor they replaced? I have no idea. Anything I and most other shops tried didn't fix the issue.
Just passed 140,000 miles, so she's barely broken in on the 2.3l.

 

[scotts90ranger]

There's two things I can think of that would cause this if that fixed the issue... One is the cat was broken up from misfires in the past overheating the cat (misfires from failed spark plugs or wires are the biggest cause of this) and breaking it apart, sometimes chunks would turn sideways and nearly plug off the flow, which does happen... Other option for the fuse blowing and is the most likely cause of that is a short on the heater circuit for the oxygen sensor, I'd have to see a wiring diagram to be sure (too late in the evening for that) but that would definitely blow a fuse in the right situation.

 

[Sweersa]

There's two things I can think of that would cause this if that fixed the issue... One is the cat was broken up from misfires in the past overheating the cat (misfires from failed spark plugs or wires are the biggest cause of this) and breaking it apart, sometimes chunks would turn sideways and nearly plug off the flow, which does happen... Other option for the fuse blowing and is the most likely cause of that is a short on the heater circuit for the oxygen sensor, I'd have to see a wiring diagram to be sure (too late in the evening for that) but that would definitely blow a fuse in the right situation.

The fuse blew once while driving which stranded me, and kept on blowing (on crank) on the half a dozen or so replacement fuses during troubleshooting after I got her pulled home when I was dealing with that years ago. The truck sat untouched for 2-3 years at a horrible shop that kept putting it off, then after putting in a new battery and alt at a better shop I towed it to (the one that most recently worked on it), she came back to life without blowing the fuse but it still had the issue in hot weather going over bumps etc. I drove it for years, trying various things to fix, including replacing grounds, etc. Very strange! I'm grateful it seems to be fixed now, as I love driving this truck. I've put more than she's worth into her over the years because it's special, and I expect it will serve me well for many more years to come. I even put full coverage back on it because of how horrible some of the drivers are in my area (and too many deer). I attached a few recent photos of her.