HELLO!! I have a 1994 ranger (obviously) 2.3 2x4 5 speed manual. I bought it about 2 weeks ago and it had an existing issue of running rough with no power, and no power steering. Changed both power steering lines and belt tensioner since that was needed as well. Once both parts were on and it was running it still ran rough for about 3-5 minutes then cleared up and drove/ran fine. I drove it around my area around 55 mph and it drove fine.
the day I took it to get it tagged it started running rough again. Limped it back home and by the time it got there the high heat paint on my muffler had melted off. I thought cat was clogged so took out O2 sensor to check and it still ran rough. MAFS is clean, new cam position sensor, new plugs and wires, and new driver side coil pack and still runs rough.
if I let it sit for a few hours and try again it runs fine for a few minutes then goes back to running rough. I have no CE light and when I took dash apart to check bulb it was fine. Changed with existing bulb that works and still nothing. I checked the voltage at the cigar lighter as I read that was hooked to the same fuse. I’ve checked all fuses and they’re all good. What could my issue be with either the light to get codes or the running rough issue

i know I’m a bit long winded in the posts but I’m a diesel tech and have to be thorough with my write ups. Figure more info is better than not enough. Thank you so much again for any help

 

Welcome to the forum

The CEL should come on with key on, that means computer has booted up, it Grounds the CEL bulb, pin 17 on computer
When you crank engine CEL should go off, that means computer is getting a timing signal from ICM(ignition control module), spark module

So you may have a computer issue

But the intermittent rough running is most likely the ICM, common issue on 1989-1994 2.3l Rangers, symptoms include OK running until warm
Its on the front of lower intake so it can be cooled by the fan as these run HOT, which is why they had issues
The 3 bolts that hold it are Grounds and they can get rusted out so intermittent ground issues

In a 1994 computer should be in engine bay drivers side between firewall and inner fender, down low, follow main wiring harness, computer has 60 wire connector

But first check if computer is grounding pin 17 with key on

Look here: https://www.therangerstation.com/tec...ry/OBD_I.shtml

This is for the OBD1 connector, its on the main wiring harness usually near the engine fuse box, might still have a Cap on it with "EEC" printed
In the link the STO(self test OUT) slot in this connector is labelled
That's the Ground wire for CEL bulb, comes in from computer then goes out to the dash CEL bulb, often used a pink/green wire, in and out
Any way if key is on and you GROUND that slot, CEL on dash should come on, that tests the wire and bulb

If you hook a test light, or volt meter, to Battery Positive and that STO slot then you should see 12volt with key on if computer is grounding pin 17 like it should

 

So, I have gone through the process of checking fault codes through means of a bullet marker light I picked up from work. The one that caught my eye was obviously the misfire and a code relating too the icm. I had the truck running well on 1/20. Same problem as before, it ran fine after being jumped then fell on its face. Today (1/23) I replaced the icm. Now I have no spark to and truck is not even trying to fire.

 

What were the exact codes?

ICM(spark module) needs a good ground to work, no spark without it
One of the 3 bolts that holds it to the lower intake is "the" ground, can't remember which, but all 3 are needed

You can do 50/50 test to confirm its a spark issue
50/50 test
Spray fuel into the intake, gasoline, ether, carb cleaner, ???
Try to start
If it doesn't fire or start then its a spark issue
If it fires/starts and dies its a fuel delivery issue
50/50 instant results

On a 2.3l Limas there is also the possibility of a broken or slipped timing belt, so no compression and no start even with fuel and spark
So just make sure the belt is turning when engine is being cranked

 

You shouldn't need to remove the dash to check if the lamp is working. Just crank the engine. If the lamp is good, it lights up.