Cannot see any photo.

You have no ballast resistor or crank sensor per se. The computer figures out when to pulse the injectors via the hall effect sensor/ distributor pick up. Later models have true crank sensors down by the tranny. It is needed to tell the computer which injector to fire. Since you only have 2 throttle body injectors to feed 8 cylinders the ECM only need to know when to fire the 2 injectors, not which of 6 or 8 injectors to fire.

That ground wire at the bottom of the coil's mounting foot is the computer ground.

If this was disconnected the computer was trying to find a ground somewhere else. Perhaps the ECM is damaged. The ECM does have it's own fusible link that is not really bundled with the others.

Is your check engine light still coming on when you turn the key to on?

The asd relay powers the coil, fuel pump and injectors. Can you hear the fuel pump turn on for 2 seconds when first turning the key to on?

It is hard to really definitively blame the ECM, unless a replacement solves the problem.

Look up your engine computer on Rockauto, under electrical or engine management it will list an engine control computer, and show a pic. If you click on the blue part number it shows all the models the part fits. Some Pick ups share the same computer on some years. Perhaps a junkyard. Try wiggling the connectors at the computer. Try removing and inspecting them for moisture, corrosion, debris.

Besides blaming the coil you had tested, I am out of ideas.

 

I've had the battery out for a day/2 so the computer can clean itself of codes. It was giving me all kids from the testing I did. Should have battery in today and new codes.

I could hear the fuel pump when in the "on" position and it was still giving codes.

Am I going to be looking at replacing the computer in the hood over engine or the one in the glove box compartment?

What's the difference?

 

I dont know much and didnt read the entire thread just a few posts.

Could be a bad ground, bad grounds cause havoc as I had an issue with that.

Might be a bad computer, $20-$60 fix if its the SMEC, could be the PCM variety.

I have a brain fart now and dont know the word for the thing that screws onto the exhaust manifold or exhaust pipes for measurements. Could be that. Had one on my Jeep YJ, those are expensive, best to replace with a few different junk yard ones then a new $100 one.

 

Do you mean the O2 (oxygen) sensor?

 

An O2 sensor will not cause a no start, nor do they cost 100$. Perhaps on a vehicle which needs 2, but a '91 does not.

I have read on Bitog that Dodges do not like Bosch 02 sensors. Apparently NGK/NTK sensors come/ came stock on all mopars and many report better fuel economy and better longevity with them.

I am on my second Bosch 02 sensor, and I suspect it again as I am running slightly rich. This one if for my '89, apparently does not fit a '91.
http://www.amazon.com/NGK-23023-Oxyg.../dp/B000C5PY1S

I did not know they put any computers in/ behind the glove box. Perhaps this is for the ABS brakes or air bags.

Look at the photos on Rock Auto.

 

Computer behind the glove box is the RWAL computer. Airbag computer is under the drivers seat.

 

Replaced the computer and it works now. Run rough warm, but a least it starts now.