86 FJ60 Computer test and Vacuum switches... (1 Viewer)

Joined
Mar 31, 2011
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So, my brother is not a genius. He decided to connect a jumper between the connections on the green wire connector that's connected to my carb because he thought it was to power the 'hair dryer' for my carb. Afterwards my truck didn't run correctly. It doesn't idle correctly...the rpm's fluctuate about 100 rpms up and down and it won't idle by itself at all now.

My question is, does anyone know off hand what he might have done? Did he fry the computer? Or maybe just this portion of the computer? We've traced all vacuum lines and checked compression at the cylinders and everything seems right, except for one of the vacuum switches isn't working. I'm curious to know if the computer (which might be shorted) controls this vacuum switch or if this vacuum switch is failed regardless of the computer.

Another important question...what is the part number for these vacuum switches??? It's just the switch with one vacuum tube coming out, and one wire connect on the back (hot I assume). It looks like a top. I've been to the local parts depots and they can't even find anything like it.

This all started because I was having vapor lock issues. We checked the charcoal filter as per this website and it's good. The 'hair dryer' for the carb wasn't connected, so that's when dillhole tried to find out where the leads went and further :censor: :censor: up!

Help before I slaughter my idiot brother, as this is my only means of transportation!

1986 FJ60
Old Man Emu 4" suspension lift
HEI Dissy
Electronic fuel pump
Mastercraft Custom suspension seats
disconnected Safari Snorkel
 

1911

chupacabra
Joined
Aug 11, 2006
Messages
6,174
Location
Parker County, Texas
 
 
So, my brother is not a genius. He decided to connect a jumper between the connections on the green wire connector that's connected to my carb because he thought it was to power the 'hair dryer' for my carb. Afterwards my truck didn't run correctly. It doesn't idle correctly...the rpm's fluctuate about 100 rpms up and down and it won't idle by itself at all now.

My question is, does anyone know off hand what he might have done? Did he fry the computer? Or maybe just this portion of the computer? We've traced all vacuum lines and checked compression at the cylinders and everything seems right, except for one of the vacuum switches isn't working. I'm curious to know if the computer (which might be shorted) controls this vacuum switch or if this vacuum switch is failed regardless of the computer.
No, he didn't do anything to the computer, he just rendered the idle fuel-cut solenoid closed and inoperable. Hook it up again; it needs to be grounded to open and let gasoline into the idle circuit. That's all the "computer" does, it just grounds the solenoid. You can bypass the computer completely by grounding the solenoid yourself if you want to - lots of folks do this (myself included) when the old cold-soldered connections on the "computer" circuit board go bad.
 
Joined
Dec 14, 2007
Messages
1,994
Location
Nelson, BC
 
 
There's a 'computer' fuel control in an FJ60? Might be part of my electrical troubles, time to search...
 
Joined
Mar 31, 2011
Messages
9
There's a 'computer' fuel control in an FJ60? Might be part of my electrical troubles, time to search...
Not so much a computer as a circuit board for the emissions garbage...which is expensive to replace and a waste of space. It is located under the drivers side kick plate...the black box.
 
Joined
Mar 31, 2011
Messages
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Anyone happen to know the vacuum switch part number I mentioned above?

Thanks 1911!! Everything is all better now. Now we're trying to find the relays for the 'hair dryer.' We found one under the passenger side kick, but are not sure where the other one is. Any ideas? I keep telling him we should just connect it to a switch and I can turn it on as needed, but he wants to test the system in its oem state...Any help?

BTW, the part number for the discontinued vacuum switch is:
83391-12050 : SWITCH, VACUUM
 
Joined
Feb 5, 2005
Messages
4,495
i think it just runs off the temperature sensor on the manifold. follow the blower wire toward the firewall, it should just bolt near the rear of the manifold.
 

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