Heating issues - Replaced Tstat/Heater control valve/Flushed Core (1 Viewer)

[PeaksFJ]

91 FJ80 3FE

Now that the days of cold are coming up, I'm finding I do not have adequate heat coming through my dash vents. I've had this thing for about a year now and haven't had heat since taking ownership

I've read trough countless topics/post and followed most of the suggestions. For the most part, they all echo each other - Bad heater control valve, T-stat stuck open, flush heater core etc. I've tested the new T-stat for functionality and it works properly.

This was completed about 3 weeks ago:

1. Flushed System (Rad/block/Heater core)
2. New Toyota T-stat (top rubber ring properly seated)
3. New Heater control Valve (had it wide open)
4. All fresh T-Red Coolant
5. New Temp Sensor

- The 80 gets up to temp reasonably quick. After completely warming up it will feel somewhat warm through the dash vents, but after driving a few miles that warmth dissipates and becomes cool.

- The heat coming through the floor vents is hot and can warm the cabin somewhat, however, this isn't going to help when I need defrost. The heat is consistent and never fades.

I don't know that there is air in the system. I spent time with a funnel while it was running to burp it. Plus, the fact that there's pretty good heat in the rear floors, has me scratching my head.

I'm just spitballing here... Is there a blend door or actuator that could be faulty? I'm guessing most of that system is mechanical anyway? Sounds like its operating properly.

Usually I can figure these things out but this one has me stumped. I'm pretty jealous on posts in other places saying the heat others have nearly sweats them out of the cabin. I want that... or something close enough to it.

 

[Malleus]

Your problem sounds like the diverter motor either isn't working or the linkage is FUBAR.

If the attached files don't help, let me know and I'll send you the entire section.

 

[jonheld]

Is there a blend door or actuator that could be faulty?

There is absolutely a motor controlled blend door behind the dash.

 

[PeaksFJ]

Thank you for the resource, Mallus. I'll look into that.

Thank you Johnheld

I'll follow up with a progress report once I've had a chance dig into it.