What are these electrical, vacuum sensors and plug used for

Tiny
PAPAW51
  • MEMBER
  • 1984 JEEP CJ7
  • 4.2L
  • 6 CYL
  • 4WD
  • MANUAL
  • 150,000 MILES
Can anyone tell me, definitively, what these electrical and vacuum sensors and plug we're for before retirement. Top of manifold, with red plastic. Vacuum fitting at center of picture. Electric connector with wires sticking out, about 7:00 o'clock.
Mostly curious as they are not connected in any way at least on the outside. Thanks in advance.
Monday, March 4th, 2019 AT 8:12 AM

8 Replies

Tiny
STEVE W.
  • MECHANIC
  • 13,463 POSTS
Red one looks like a coolant temperature sensor, the vacuum connections would be controlled by temperature as well. That one looks like the EGR thermal control. It prevents EGR operation unless the engine is up to temperature.
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Monday, March 4th, 2019 AT 1:57 PM
Tiny
PAPAW51
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Okay. Thanks Steve. That will give me a starting point to dig a little deeper.
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Monday, March 4th, 2019 AT 3:19 PM
Tiny
STEVE W.
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This is the vacuum line diagram for that Jeep and engine. That may help.
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Monday, March 4th, 2019 AT 5:18 PM
Tiny
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Well what do you know. The black vacuum fitting has a name now. "CTO valve". That is helpful. It is also interesting that the vacuum advance for distributor is taken from manifold vacuum, and not port vacuum from the carburetor.
I probably should clarify that my Jeep only runs one vacuum hose. Vacuum advance to distributor. All other vacuum has been plugged, disconnected, or just plain removed. I was asking about those fittings to understand what they did originally, so as to get to know my new lil buddy.
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Monday, March 4th, 2019 AT 5:46 PM
Tiny
CJ MEDEVAC
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You'd be better off keeping that stuff disconnected and installing a BBD carburetor like a '79 (like the one on the right in my first picture)

Look! "Rick" just got his BBD from EBAY for $99.00 (what a deal!), The old stepper carburetor quit "steppin" years ago

Having hands on with his Jeep, we got rid of the crap, insured everything that was necessary was connected correctly.

Notice the same crap as yours is no longer in use.

Basically, he now has a 1979 CJ7 (engine wise), the best CJ year ever!

What issues are you dealing with, with your Jeep?

The Medic
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Saturday, March 9th, 2019 AT 3:33 PM
Tiny
PAPAW51
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Hey Sarge, Thanks for the reply. Was not intending to hook any of it back up. I was just wondering what each of those were in case one of them might be a future issue as the sit now. I've been reading some of your stuff here, and at your recommendation to another CJ7 owner, I removed what was left of the ECM harness and the module itself a couple of Sundays ago. Cleaned up the firewall nicely. I'm in the process this week of replacing the column mounted ignition switch. Traced down the power feed for the blinkers and wipers to that spot. Mine has a Holley two barrel on it now, but the Carter came with the Jeep, in a box. No steppers attached. Someone has gone before me and bypassed the ECM putting me ahead a step or two in the process. Ha. The Lil guy is just dirty and tired. The main issue was the turn signals. Let me finish getting those going, so I can drive it on the street. I would be very happy to have your help with turning this Lil guy into a reliable get arounder. That's it for now. Don't want to go too long here. Look forward to hearing from ya.
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Sunday, March 10th, 2019 AT 2:35 PM
Tiny
CJ MEDEVAC
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Nothing like an Offenhauser Intake and a 390 4 bbl Holley on a 258.

I hope my other answers on the other posts have been helpful.

Just to clean things up a little, you can replace some of that stuff with 3/8 and 1/2 plugs. Some have the raised square heads, some have the recessed squares you install with a ratchet extension. Whatever gives you that Jeep warm fuzzy!

A better/ bigger pic of your buddy would look nice on here!

Glad to hear you are almost road ready again.

Need me again?

Be sure to start a new post if your Jeep fix subject changes, ask for me in the beginning dialog if you want me to join in.

See you soon!

The Medic
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Sunday, March 10th, 2019 AT 4:05 PM
Tiny
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Will do and thanks again.
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Sunday, March 10th, 2019 AT 4:09 PM

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