Bypassing Heater Valve on Renix 87

[tadchad]

Has anyone bypassed the heater control valve on a Renix 87 MJ?

 

I saw a couple threads on here about it, but wasn't sure if it is any different in a renix? I don't believe I have any additional lines coming off the main heater hoses that feed the heater control valve. I have a 1987  2.46L, 4 Cyl, TBI : Powertrain 5-speed manual, floor gear shift, 2 W/D

thoughts?

 

thanks.

 

 

[mikekaz1]

plug the vacuum line. replace hoses to two straight hoses or put hose menders in. done

[87MJTIM]

plug the vacuum line. replace hoses to two straight hoses or put hose menders in. done

 

Correct me if I'm mistaken, but with the Renix, there is the pressure bottle to contend with.  Wouldn't you need a T pipe adapter?  Straight hoses to the heater core would not work.

 

Does anyone have a part number for a T adapter that replaces the vac fitting?

[tadchad]

How do I tell if I have a renix or not? I guess I am assuming that since it is a 2.46l 87 it is a renix

[87MJTIM]

I don't think the 2.5 is considered a "Renix."   But, then again, Renix is associated with the fuel delivery system.

 

If you have a pressure bottle on the passenger side fire wall, then you probably have the heater control vacuum valve.

[Rockfrog]

The heater control valve was also used on the HO (open cooling system) vehicles as well. It wasn't just a Renix issue.

How to tell if you have a Renix? Well, the TBI 2.5L's used a Renix control system. Heck, the ICM and coil on my buddies 1990 2.5l YJ looks identical to the one in my 88 4.0L MJ.

 

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[cruiser54]

Just eliminate it with metal splices no matter what. No big deal what it is. 

[tadchad]

Great info , thanks everyone appreciate the help, I just bought it this weekend so I'm excited to get started , it's my first jeep and first mj

[cruiser54]

Great info , thanks everyone appreciate the help, I just bought it this weekend so I'm excited to get started , it's my first jeep and first mj

And make sure your heater blend air door is adjusted correctly.....

[tadchad]

so one more quick question, in the pic coming off my intake manifold in the rear of the engine (red line) goes to my heater control valve, is this the line that I hook directly up to the core, the tube in the front of the engine (in yellow) goes from my water pump to the intake as well, and then the line running left of the condenser (in red) is also going back to the heater valve, so am I correct in saying whatever lines enter the heater control valve are the ones that get directly connected to the heater core? just want to make sure I don't have to reroute that front tube highlighted in yellow.

 

thanks

[Rockfrog]

So the one coming from the thermostat housing to the valve goes directly to the core, best to run a new line there.

Then you will need a second line from the back of the intake manifold, again directly to the core. The 2.5L used a heated intake as it was still a "wet intake" before it got MPFI in 92. It needed the extra engine heat to help keep fuel atomized.

 

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[tadchad]

Cool then I'm tracking ! Appreciate it

[Rockfrog]

While you're in there I would consider swapping to the later model water pump outlet (front red hose) it was a formed steel outlet, and eliminated some hose bends (aka chafe points). It may list as a 4.0L part but the 2.5 and 4.0 used the same waterpumps.

 

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[tadchad]

Which line goes in the top of heater core and which line goes in the bottom of the heater core?????

[64 Cheyenne]

Doesnt really matter with coolant circulating all the time. If you wanted to be mechanically correct then pressure in at the bottom to eliminate any trapped air. On the 4.0 that I have done, went Tstat housing out, to top of heater core in, keeps lines straight and not crossed or twisted.

[tadchad]

ok, I ended up running the line from the manifold to the bottom (in/supply) and the tstat housing (out/top) just as you, kept it pretty clean. thanks.