Im lost !!

[rangermonkey]

Hey guys let me first thank you for all of your help in the past, this is my first post but I have spent hours and hours searching the archives for past issues on other trucks.
I'm currently working on a 1994 4.0 4x4 with a real rough idle. The only code I was getting was 159 mass air is or was out of range. I replaced maf after a thorough cleaning didn't change anything. Next I checked for air leaks in the intake box/tube. Then I cleaned the throttle body and checked all vacuum lines.Reset the pcm then retested. Same code 159. I then replaced the Idle air control, reset/retest got code 159 and 513 which is pcm internal failure. The truck always started real well but would idle rough and choke you out with gas fumes from the exhaust. I removed the pcm to inspect it,.no burnt smell but the board was an off color green/yellow. After I cleaned the ground up and reinstalled it it won't start. Now I'm getting codes 159,114 and 116. 114 intake air 116 coolant temp. I'm so lost right now and I need some help. Sorry for the long post.

 

[adsm08]

Sounds like you might have a bad computer. Or some major wiring issues.

 

[rangermonkey]

Everything looks fairly unmolested on the harness, all the sensors appear to have been factory. There are two head scratchers though. The coolant temp sensor that I got has a flat square connection but the one that's on the truck is round. Then there's a mystery wire that was just hanging under the motor. Its white with a red stripe and has a push type end like on the oil pressure sending unit. I have no idea what its for but its hot 12v.

 

[adsm08]

Well it sounds like the parts goons got you the wrong coolant temp sensor.

The coolant temp sensor wire (the one for the gauge) should be red with a white stripe and the oil pressure wire should be white with a red stripe. Both of those should be 12V hot with the key on.

 

[rangermonkey]

After a little more digging I figured out that the round style connector for the engine coolant sensor matches a 1993. so i guess i have some kind of left over on model year change.
Does anyone have a schematic that shows the harness where it connects to the oil pressure sending unit ?