91 z28 tpi 2000 miles on new 350. Car has been stalling out and very hesitant lately so i decided to take it to the chevy dealership. They told me that 7 of the cylinders are running at 400 degrees and 1 cylinder at 200 degrees. What does this mean and what can happen and what causes this?

they probably put an infared thermometer on the exhaust ports. the one at 200 degrees would indicate a rich cylinder, check your ignition (plugs, wires, cap, rotor) if the colder cylinder plug is fouled, you could have a bad injector, check the injectors too, if they are the stock injectors, they are probably bad. you shouldn't drive it if you have a misfiring cylinder.

Yes, sounds like a bad injector, or possibly a bad spark plug or spark plug wire. Do an ohms test on each injector. They should all be around 14 ohms or more. Any less than 12 ohms and its bad.

tested the injectors and they are fine. Chevy says after 2 days of trying to find the problem put in a new ecm chip and now she is working like the day i bought her. thanks for the input guys.

well if that fixed the problem great. but that doesn't explain the one cold cylinder. the injectors work in banks, 1,3,5,7 together and 2,4,6,8 together. so if it were an ecm issue either bank 1 or 2 would have problems, not just one hole. might have been mis diagnosed on the cold cylinder.

ill have to find out some more about that thanks for the comment.