can the iat sensor on a 93 z28 make the car run lean i got a new fuel pump new pressure regulater and the car is still running lean manifolds turning a little red and surging down low

 

You should be able to use a multimeter to check resistance of the IAT sensor by unplugging it and checking it cold and hot. Resistance should decrease with heat.

It might be possible but I would think it would be something more drastic, such as timing, for the manifolds to be glowing.

 

A lean condition will not usually cause glowing manifolds. A rich condition can for sure. A lot of unburnt fuel may come out of the heads while it is still burning. BUT the number one reason for glowing manifolds on this board is a restricted exhaust. You should put the particulars of your car in your signature but since you didn't we will assume you have a cat and if so, it is probably plugged. If you can't check back pressure, try unhooking the exhaust before the cat and see if the glowing goes away. Should have a lot more power and pep too.

Dave

 

Lean causes glowing headers. You have to be rich almost to the point of hydrolocking to glow the headers.

 

short run down started this every since hotcam spun rod bearing rebuilt motor still doing it no cat on it either fuel pump and pressure regulater all new