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1993 Rodeo 2WD 4ZE1/T5 CA Spec - 2016 RAM1500 Pentastar (22mpg) - 1986 RockZuk on Toyota Axles
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(Vacuum Diverter Valve?) = "Thermal Valve" by most hood diagrams. Jerry said he needs about 12 himself they're backordered for months, I think that implies a batch gets manufactured time to time. They go for about $60-$120 used if you message someone that parts out Isuzu's from here. I was gonna pay it when the first adhesive I used melted immediately, JB weld worked. If you try to get the hoses off of it or unscrew it out of your thermostat housing, 99% chance of breaking it. I've seen a couple people claim to have bypassed it but I don't think you can with A/C and definitely not in CA. 1/2” ID hose will work for the top connectors, (the annoying one)

"The little blue one" is what you thought was next to his coolant sender in the intake manifold, right? Looked like the broken fuel kill switch/oil light sender on mine but I can see how with the plastic busted off what looks like a wiring male spade is the thing that slides up and down based on temperature.

The biggest problem on getting this truck to pass smog in CA is that the hood diagram is going to show the IAC attached to the throttle body and instead it's going to have to go to a DIY hole in the plastic of the intake tube, either one is a visual fail. You used to be able to deface the hood diagram and they'd just look for anything disconnected but they've gotten even more stringent in CA since I last dealt with it, I doubt it'd work.

I think what you'll need to do is glue the little blue valve back together leaving it always open or always closed, do the "straw trick" inside your BackPressure Transducer whether it's good or not, and basically go EGR to ported vacuum with an orifice restricting the diameter somewhere in between in a way that looks like the little blue thermal valve and BackPressure transducer are hooked up. That still leaves the modifications necessary to get the IAC hooked up probably failing you on visual.

First step is finding and understanding every piece on your hood diagram, second step is determining how many things that aren't on your diagram got swapped in with the throttle body and intake manifold.

I believe the felpro head gasket set and full gasket set come with both versions of the TB gasket. Don't buy it from Rock Auto on closeout, it will be a knockoff. Amazon $92 or so.
 

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1993 Rodeo 2WD 4ZE1/T5 CA Spec - 2016 RAM1500 Pentastar (22mpg) - 1986 RockZuk on Toyota Axles
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Here is a pic of the diagram on the undeside of the hood.
This will be very hard in CA. If you can still get away with removing hood diagram, or putting a different color hood from a federal truck of a different year so it's obvious it's inaccurate, it'd be possible but hard. If that is an automatic fail now, I'm sorry to say it's impossible to register in CA.
 

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1993 Rodeo 2WD 4ZE1/T5 CA Spec - 2016 RAM1500 Pentastar (22mpg) - 1986 RockZuk on Toyota Axles
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Bribing the smog guy used to be so common they now do undercover operations really regularly in SoCal. They'll all fail you on visual no matter how clean it reads at the tailpipe, just because you could be an undercover cop that will throw him in jail. Unless you can convince a smog shop to do it based on a missing diagram after ripping it off or swap in the hood of a federal truck and he believes you that yours looks different for no reason other than your CA smog system, you're wasting your time trying until you find a plenum (usually gets labelled upper intake manifold on eBay) and 2bbl oval throttle body, then you still don't have enough large ported vacuum ports. Easy enough to convince someone was a repair rather than modification, even the throttle body is findable, finding an upper manifold/plenum that isn't rusted out to bolt it to may be impossible.
 

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Discussion Starter · #45 ·
Here is that air switch valve with broken nipple. Third pic
Bribing the smog guy used to be so common they now do undercover operations really regularly in SoCal. They'll all fail you on visual no matter how clean it reads at the tailpipe, just because you could be an undercover cop that will throw him in jail. Unless you can convince a smog shop to do it based on a missing diagram after ripping it off or swap in the hood of a federal truck and he believes you that yours looks different for no reason other than your CA smog system, you're wasting your time trying until you find a plenum (usually gets labelled upper intake manifold on eBay) and 2bbl oval throttle body, then you still don't have enough large ported vacuum ports. Easy enough to convince someone was a repair rather than modification, even the throttle body is findable, finding an upper manifold/plenum that isn't rusted out to bolt it to may be impossible.
Do you know where the round connector coming from TPS on a oval TB hooks up to? I posted that question elsewhere but thought I would ask here incase you had the answer. Remember, I seem to have a later model TB but am contemplating replacing with the original oval TB..
 

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Discussion Starter · #46 ·
Bribing the smog guy used to be so common they now do undercover operations really regularly in SoCal. They'll all fail you on visual no matter how clean it reads at the tailpipe, just because you could be an undercover cop that will throw him in jail. Unless you can convince a smog shop to do it based on a missing diagram after ripping it off or swap in the hood of a federal truck and he believes you that yours looks different for no reason other than your CA smog system, you're wasting your time trying until you find a plenum (usually gets labelled upper intake manifold on eBay) and 2bbl oval throttle body, then you still don't have enough large ported vacuum ports. Easy enough to convince someone was a repair rather than modification, even the throttle body is findable, finding an upper manifold/plenum that isn't rusted out to bolt it to may be impossible.
yea.. I want to do it right and try to connect the right components and try to get it to pass smog. Let's see.
 

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Actually I just remembered that throttle body has a big vacuum connector on the top for the IAC, so it solves that problem too.

If you look under the BackPressure Transducer there may be a third port on the bottom. You could maybe block it off with glue or a rubber cap then run a line to that vacuum port on top of your throttle body so it creates an excuse for that one to be capped off, "I thought it was a typo but a mechanic told me it's because they considered it an exhaust line not vacuum".

Then the one you currently have going there could go under the throttle body to the Thermal Vacuum valve, then back up to the underside of the throttle body, it'll work just fine if all of them are stuck open all the time as long as it's ported vacuum not manifold vacuum that you run it to and somewhere in there you reduce the diameter to about the size of a red hose off a WD-40 can. I'm not 100% sure which is which but I think the two vacuum lines on the underside of the throttle body are 1 ported 1 manifold vacuum and the one with your VSVs on it seems more likely to be the manifold vacuum, so I think your ported is the one it's supposed to go to by the hood diagram anyways.
 

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1993 Rodeo 2WD 4ZE1/T5 CA Spec - 2016 RAM1500 Pentastar (22mpg) - 1986 RockZuk on Toyota Axles
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yea.. I want to do it right and try to connect the right components and try to get it to pass smog. Let's see.
The only way to do it all the way right involves finding the old style throttle body AND upper intake/plenum AND finding a working thermal vacuum valve. There is no way to pass visual in California without cheating a little with that hood diagram and that throttle body. Not for any amount of time and money.
 

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1993 Rodeo 2WD 4ZE1/T5 CA Spec - 2016 RAM1500 Pentastar (22mpg) - 1986 RockZuk on Toyota Axles
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The only way to do it all the way right involves finding the old style throttle body AND upper intake/plenum AND finding a working thermal vacuum valve. There is no way to pass visual in California without cheating a little with that hood diagram and that throttle body. Not for any amount of time and money.
There's a lot more junkyards that let you pull your own stuff here, if I see one I'll pull it and the EGR components and next time I'm visiting family depending where you are maybe we could swap them. I'll probably be staying in Newport Beach for at least a couple days in August. Probably go see my wife's family in Santa Maria/Pismo sometime too, not sure if it'd be the same trip or sooner. I only ever see v6s but I did find a junkyard I haven't been to with 11 Isuzus, 4 of them likely to have the 2.6 that have been there less than a month and a half. But it's an hour away in Phoenix where it's over 100° already, waiting for a cloudy day.

I can't remember, was it running good and you just needed vacuum stuff handled for smog? Where your lower intake was bolted to the head it looks very rusty, these trucks can keep running pretty decent with a bad head gasket leaking coolant internally.
 

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Discussion Starter · #50 ·
There's a lot more junkyards that let you pull your own stuff here, if I see one I'll pull it and the EGR components and next time I'm visiting family depending where you are maybe we could swap them. I'll probably be staying in Newport Beach for at least a couple days in August. Probably go see my wife's family in Santa Maria/Pismo sometime too, not sure if it'd be the same trip or sooner. I only ever see v6s but I did find a junkyard I haven't been to with 11 Isuzus, 4 of them likely to have the 2.6 that have been there less than a month and a half. But it's an hour away in Phoenix where it's over 100° already, waiting for a cloudy day.

I can't remember, was it running good and you just needed vacuum stuff handled for smog? Where your lower intake was bolted to the head it looks very rusty, these trucks can keep running pretty decent with a bad head gasket leaking coolant internally.
Hey Thanks Timmay, I appreciate the gesture. If you do go, I definately would need the complete manifold set up and the vacuum switch valves. I may PM you..
 
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