Carbed engines have computers?
Senior User
Joined: Jan 2004
Posts: 157
Likes: 0
From: Minneapolis, MN
Yes, carbed engines did have computers in the early years OBD1. They had a feedback circuit that would make slight alterations to fuel mixture. It also controlled the other necessary functions like timing. Not sure what years had it, but my my 1984 Ranger has this setup. Yes you can get codes from this system.
Elder User
Joined: Dec 2002
Posts: 559
Likes: 0
From: South Carolina
There's a Haynes manual that covers this - the setup is called MCU I think, and the book describes diagnostic procedures. It's worth having the manual if you've got one of these. I think they only lasted a couple of years
Senior User
Joined: Oct 2001
Posts: 268
Likes: 0
From: North Texas
The earliest computer systems were EEC-III, and you got codes by turning the key on, grounding a plug (gotta think where it is) and then counting the number of times the check engine light flashes.
Crud; I can't find the info. Yeah, get hold of a manual, preferably Ford but Haynes are OK.
Crud; I can't find the info. Yeah, get hold of a manual, preferably Ford but Haynes are OK.
Elder User
Joined: Jan 2004
Posts: 767
Likes: 1
From: Franklin, GA
I think since '81 pretty much all vehicles had some sort of brain box in it. The first ones didn't regulate much, just monitored things so you could pull flashing light codes to narrow down troubleshooting a problem. I remember a cab swap on a '79 GMC to an '81 cab ('79 rusted out) and I bypassed the silver box on the '81.
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Senior User
Joined: Jan 2004
Posts: 139
Likes: 0
From: West Texas
your 84 has what is known as eec-iv, it is pretty much a computer assisted carb system. your computer is under the dash just to the left of the radio. if you take your truck the can test the computer, but they want about 80$ to do this. if you go to vato zone they will sell you alone with a new one for about 100$. now if your engine is running well enough to drive to the ford house, there is nothing wrong with your computer.
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Senior User
Joined: Aug 2004
Posts: 181
Likes: 0
ok cool my 88 ranger has the mcu system in it and when I try to pull codes the scanner says that the vehicle does not respond. I'm having a rich mix and bad erratic idle (hops around 50-100rpm) any ideas?? my engine is 2.0L asian built 2bbl new complete tune up. even rebuilt carb still running the same.
