Ok, trying to figure some things out. Rig is a 87 4Runner, previous owner toasted motor. Blew HG, cracked head, melted thermo, and trashed a piston.

Replaced head, piston, and thermo to get back on road. Drained and flushed coolant system several times and replaced freeze plugs. Also put in new plugs, wires and o2 sensor. Dropped cat and checked it and can see through it.
Drove awhile with no cold start sensor, eventually replaced that. Blew out manifold exhaust and down pipe gaskets, drove for while like that then replaced.

What im trying to figure out is the reason for the glowing manifold. I figured it was caused by the exhuast leaks, but the repairs did nothing. The motor gets hot sometimes too, sometimes normal driving with cause temp guage to climb high but will drop down. Also noticed before going up alot of hills, the manifold glows some but when getting to the top its really bright. Any ideas? There is a slight coolant leak, so some air is getting into system, not sure if that could cause it.

 

the exhaust manifold is red? I would check the timing.

 

This sounds like a lean condition to me. Check for vacuum leaks and whatever else you think of that would cause a lean condition. Was your truck idling high when you got it running after the rebuild then you turned down the idle screw or retarded the timing or anything? Is the engine otherwise performing well?

Also is the whole manifold glowing or just 1 hole?

 

I had a bad TPS that caused a glowing red manifold, course that was on a Cadillac so YMMV.

 

The whole manifold glows red hot.

I adjusted idle screw down when motor was idling really high from exhuast leaks. Have since adjusted it.

Would be good thing to check timing.

Motor runs good, gets hot while driving somtimes.

 

It's your timing.

 

Been noticing that the motor is somtimes staying at a high idle, but still when gas is tapped it drops down. TPS issue?

 

Like I said, my issue with glowing manifold was a faulty TPS and was dumping a lot of fuel. It's easy to test your TPS with a cheap multimeter. However, what you describe just sounds like a tight throttle cable, or a hitch somewhere in the throttle body linkage.