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Discussion Starter · #1 ·
Hey Folks,

I have gotten conflicting results on what each port of the CTO does and how it all works. Can someone who knows with 100% certainty what each port does and how they are related to one another or not give an explanation please?? I think I have a basic understanding, however I am trying to learn a little more about the vacuum system. My particular Jeep is the 89 Wrangler YJ. There are 3 ports to the front of the engine and 2 to the rear.

Thanks in advance (Trying to become in tune with my Jeep <smile>)

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/wwwthreads_images/icons/smile.gif Hi Greg.... this is your Jeep talking....of the three front ports, the bottom is a filter...the top goes back around to a tee which is on the line that hooks to the lower port of the two rear ports.....the center port in front goes to the cannister to "purge signal" Of the two ports in back, the top goes to the center port of the circular EGR TVS....the lower port goes to the "s" port on the base of the carb. Now that I have spilled my guts, how about treating me to an oil change...Valvoline would be nice. /wwwthreads_images/icons/smile.gif
Gregg, you can see that your Jeep is willing to talk. The EGR valve is controlled from the top rear port, via the EGR TVS, so that's pretty straightforward. Water heats up, CTO operates. Same goes for the purge system. I cannot see where the CTO is connected to the spark advance, however, not like the older stuff./wwwthreads_images/icons/tongue.gif
Oh, and one more thing, your Jeep wanted you to check and see if you could get him the extra-large oil filter? You know, the optional PH8A which will increase his oil capacity. He says if you did that, it would make him feel a lot better about you letting him go so long between services. /wwwthreads_images/icons/smile.gif
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