MCU system on 83 ranger...how does it work

Reply Subscribe

Thread Tools

Search this Thread

Mar 18, 2002 | 06:56 PM

fordmanSLO

Thread Starter

Senior User

Joined: Jun 2001

Posts: 200

Likes: 0

From: Davis, CA

MCU system on 83 ranger...how does it work

I have an 83 ranger that I almost got running. Its having problems with the carb, and I want to be able to troubleshoot the MCU system, but my old chilton manual says nada? Anybody got some documentation on this, or know where to get any? Any helpful insights would by much appreciaed too. Thanks

Mar 19, 2002 | 06:28 PM

Ford 4 Life

Junior User

Joined: Mar 2002

Posts: 98

Likes: 0

MCU system on 83 ranger...how does it work

The MICROPROCESSOR CONTROL UNIT. Oh what fun! It keeps the Air/Fuel mixture ballenced. The O2 sensor tells the MCU if the carb is running to rich or to lean so make sure that it is functioning properly. I had an 83 Ranger about 10 years ago. I took it over from my Dad. It had some serious issues. The carb was flooding, It was running rich, it needed attention. I had to take it to a auto electric shop to diagnose it. Turned out the computer was shot. After going to several auto repair shops who could not get one, I found one that did. I put the new MCU in and replaced the 02 sensor. I had the carb rebuilt at the Ford dealership. It ran perfect after that. It was a serious headache but it all worked out in the end. The computer was I think around $250.00, Ford I think charged me around 300.00 for the rebuilt carb and tuning it up.

Hope this helps. Good luck!

Mar 19, 2002 | 08:10 PM

fordmanSLO

Thread Starter

Senior User

Joined: Jun 2001

Posts: 200

Likes: 0

From: Davis, CA

MCU system on 83 ranger...how does it work

Is there any way I can bypass it, just so I can get this thing running again? I got a feeling most of the electronics are bad, because it was underwater, but I'd like to see if the motor can run at least

Mar 19, 2002 | 08:55 PM

Ford 4 Life

Junior User

Joined: Mar 2002

Posts: 98

Likes: 0

MCU system on 83 ranger...how does it work

I had that option. I chose not to because the carb will not work properly, it was made to coinside with that MCU, If you bypass it you will get irregular idleing and it will not perform well(bad MPG),you may not pass DEQ. If you plan to keep the truck you might want to see if there is a different carb that can be put on that engine that does not reqire the MCU as a componant. As far as finding out if there is a different carb for that engine, a Ford dealership might know or help stear you in the right diection. I say a Ford dealership because if anyone knows about ford they would. I usually use The dealership for a diagnosis of any problems. If you plan on selling it,I would go with the first option(bypass the MCU), I think it would be cheaper. Your truck will run, just not well. I could not handle the irrregular idle. It would bother me. Then again your truck might run fine. You said yours was a 2.3L, Mine was a 2.0L, I don't beleive that would make much of a difference, but it might.

I'm not a machanic. This was just my expierience.

If you have anymore questions E-mail me. Booker63(No Email Addresses In Posts!)

Good Luck!

Mar 19, 2002 | 10:55 PM

fordmanSLO

Thread Starter

Senior User

Joined: Jun 2001

Posts: 200

Likes: 0

From: Davis, CA

MCU system on 83 ranger...how does it work

But how do I do it? just unplug it? Makes sense, I guess. I can repair it once I get it running if I know thats it. I'm not worried about the bad MPG, etc, because this is just to make sure it'll run at all, and I just want to figure out why it won't fire up by itself.

Apr 28, 2002 | 10:38 AM

1992 XE 4X4

New User

Joined: Apr 2002

Posts: 3

Likes: 0

MCU system on 83 ranger...how does it work

On my 83 that I had. I bought it with the mcu not working. I put a 2 barrel weber carb. (factory) from from a pinto. I disconnected the rest of the mcu and plugged the vacuum lines. It ran as well as a 2.3l could with an automatic. That was some years ago and I still see the truck is still on the road. Knowing how Ford likes to change parts and designs, sorry I can't give you anymore info on the pinto carb.

Apr 29, 2002 | 09:54 PM

nitro94

Posting Guru

Joined: Feb 2000

Posts: 1,100

Likes: 0

From: Wichita USA

MCU system on 83 ranger...how does it work

Those old mcu systems only control about 10% of the fuel delivery amd really don't have the ability to keep it from not running. Run bad yes but not run at all, no. Try the basics, diagnose this like a non ecu system to get it running.