What are these boxes?

[rippsnorter]

Hey everyone I have an 86 with a 2.0, beast of a motor it is, and there are these 2 boxes under the hood. anyone know what they are?

 

[igiveup]

Hello

The second one looks like a dura spark box the first on I dont know.

igiveup

 

[pedal2themetal45]

Don't know about the first one but the second one is the spark box for your ignition.
Tim

 

[Mark_88]

the first one is your ICM (Idle control module)...it's pretty much a mess of wires that act as a computer (sortof)...I wouldn't take it apart if you haven't already...even though it's dirty it looks like it's intact and should work fine...when you start to see the rubber breaking off the base or extreme rust around the connectors then you may need to replace it...

 

[rippsnorter]

cool thanks man. Is that the same as the MCU? I was told by someone else that thats what it is. I'm going to be stock flooring this truck so im gonna have to mess with it. hopefully it doesnt break. Thanks for the help!

 

[Mark_88]

Not sure what the MCU (master control unit???) does but your engine doesn't have one...the ICM controls the idle through a complex feedback system...and on some setups you can actually remove it if the carb has idle adjustments (like mine) and a manual choke (not like mine but soon to be if necessary).

I haven't taken mine apart to remove the wires that are not needed but that's mainly because I am still toying with changing the carb and intake for a different setup...but apparently the wires can be removed...

Essentially, if you are running everything stock then you don't want to remove that box unless you change out the carb...

 

[rangrfrank]

I'm wanting to remove the ICM as well ( I too have a 1986 model) and am changing carbs. Any info on the wiring mods needed would be great help. Thanks!

 

[Mark_88]

There have been a few people who have done this but I'm still not up on what is actually needed.

Bottom line is that if you have the original carb and it has wires connected to it then you probably don't want to remove the ICM. If you have upgraded to a different carb that has a manual choke and idle speed screw on the carb itself then you can remove it without affecting anything.

I kept the wire harness for this and had intended to trace the wires to find out where they went but that effort got off track and I ended up tossing the harness (I kept the ICM for some reason).

There is one wire on that mess that ran from the alternator to a relay on the passenger side fender. This one wire was used to activate the choke (IIRC) and even that is not needed if you have a manual choke.

If you happen to use an in-line block heater you can pretty much do away with the choke for cold starts if you run the heater before attempting to start. My engine would start on most days if the temps ranged from 0 to -35 C with just a half hour of block heating. The cost of which was roughly 25¢ per day (if that) but I could have easily added a manual choke and kept the battery on slow charge for those really cold days...but I liked the block heater because it also meant almost instant heat from the heater and really reduced wear and tear on the engine.

so...to answer your question...no wiring that I've seen.

Do you have the original carb?

EDIT: I did a bit of digging and I found a wiring diagram for the Idle Speed Control if you are interested...I can send it to you...there are more wires on the unit than this shows so maybe there is another diagram...but it shows it as having both an MCU and an ISC...