This truck has been a headache. I need your help folks. I can’t get this truck to pass emissions because it’s running rich and the rpm’s won’t drop after driving on the highway. I’ve replaced the 180 thermostat to a 195. I’ve opened up the computer and found junk all on the circuits. After cleaning up the computer and replacing the map sensor a second time it’s idling a bit better at start but after the highway still high rpms .

 

Check/clean iac valve?

 

Check for codes? That computer board looks like it has corrosion on it. Hard to tell from picture but was there any obvious burns?

 

I ordered a new one it arrives today. I talked to someone on Reddit who thinks i should find a mechanic that have a obd-I scanner pre 1995. I’m looking into that now. But might not find anything till after the holidays lots of places closed.

 

I wouldn't trust that new iac valve unless it's Motorcraft. Most of the new parts from aftermarket companies have poor qc and hardware at best.

Also you don't need code reader. Just need a short wire or paperclip. Plenty of videos and threads online.

 

This is the OBD1 reader. I got one from O'Reilly a few years ago. They have them at AutoZone also. Cheaper than paying someone to do it.

 

Thanks for the help. I think I’ll order a motorcraft ias. I went ahead and switch out the one in there now. I noticed the shifting is so much smoother the heat is super hot and the idle is shifting down much quicker when coming to a stop. The only downside is the rpms seem crazy when pushing the clutch in to switch gears. I don’t know if this is all temporary. I’ll drive it this weekend and report back my findings. Happy holiday folks

 

Ok stuck in my wife’s car on a trip…
so what are your thoughts on a computer replacement? It’s not something I’ll do right away but after opening it up it looks Like it doesn’t have super long. Where or who is a good source for a replacement?

 

Many threads in here you can search up for more information on replacing the computer. Some people say you can get them from RockAuto but at least when I did it they did not have my computer. I found the correct computer that matched my computer number a few months back at a company in Colorado Springs, Colorado called "The ECU Connection". There is some compatibility between some computers but which ones I do not know. Can possibly get it rebuilt but depends on if there is damage to the motherboard itself, if it's got a burn somewhere it's done for. I would also like to note that YOU CAN NOT GET A BRAND NEW COMPUTER. There has been confusion that they still make these computers but this is a 30 year old truck and many parts are not made anymore by Ford.