need expert help for over-heating problem

Heres the deal, It over-heats when going up long hills or on the highway 60+mph...
New parts:
water pump, thermostat, temp sensor, tps, map sensor, o2 sensor, ecm, fuel injector, tune up parts(plugs wires, cap and rotor, airfilter)
Have had motor apart for head gasket and new rings, bearing clearences are good.
The elecrict temp gauge dosen't work...ohm tested all wires from temp sensor to the tps and to the ecm...All check out good.
cooling system was flushed and re flushed.
valve and ignition timeing triple checked. No code
I AM STUMPED!!!!
btw it is a 89 2.0ohc sunbird but its a general question thats why i put it here.
Thanks, Eric

Check the radiator. Rads do not last forever, about 10-12 years tops. Yours may be badly corroded/blocked inside, impeding coolant flow, and/or lots of the fine cooling fins have corroded and fallen off the outside.

Otherwise, check to make sure the thermostat was not installed backwards.

Finally, was it overheating before you did all the work on the engine?

Well I never heard the car run before i bought it off a friend who said it never over heated, but the motor i got ran when pulled with 120,000 on it and didnt overheat. Whats a good way to check the rad besides getting a new one? The t-stat is a drop in one where the fill cap is.(this whole car is weird to what im use to like trucks and stuff) The rad pressure cap is weird lol. I have to take the rad out to get to it cause its on the side of the rad...The car was sitting for say about 7 years..There is no dirt or anything in the coolent.
Well thanks for your help and quick reply..Greatly appricated

Is the thermostat in upside down? This is an easy mistake to make. They are marked with which side goes to the radiator. Is the system air bound? I'd suggest a new radiator cap and having the cooling system pressure checked first.

Bob

OK t-stat goes in only one way...It goes where the fill cap is. And the actual radiator cap is on the side of the radiator and is a P.I.T.A. to get to...
Here is something for ya maybe...If i put coolant in it will slowly go down and drain into the resivor.(thinking the rad cap???) and as far as i can tell the resivor level does not change cold vs. hot. Maybe when i get time ill get a new cap and find the time to change it. As it appears i have to take the radiator out.:redface:
Thanks again

yeah the rad could be clogged & cap is a bitch to get to.you have the real big cap where t-stst goes right???sounds like aleast rad cap is bad with the level not changing.when you took rad cap off how was the level??if it was low that might be all thats wrong.good luck!!!

yeah the t-stat is under the big cap that is not on the radiator and level is full there. had the t-stat out and ran it to get all the air out of the system. The rad cap(the pressure one) is a pain cause its on the radiator about 4 inches down on the side and the radiator side thing as close close to i guess it would be called the rad support.

Anyways i dont get when the engine is cold and i put the antifreeze in it goes strait to the resivor and when its hot it dos not let anything go to the resivor then?
I will get not lazy and do it and tell everone what i found out

Heres the deal, It over-heats when going up long hills or on the highway 60+mph...
New parts:
water pump, thermostat, temp sensor, tps, map sensor, o2 sensor, ecm, fuel injector, tune up parts(plugs wires, cap and rotor, airfilter)
Have had motor apart for head gasket and new rings, bearing clearences are good.
The elecrict temp gauge dosen't work...ohm tested all wires from temp sensor to the tps and to the ecm...All check out good.
cooling system was flushed and re flushed.
valve and ignition timeing triple checked. No code
I AM STUMPED!!!!
btw it is a 89 2.0ohc sunbird but its a general question thats why i put it here.
Thanks, Eric

If all else fails.
Run a chemical block test on the cooling system for exhaust gas in the cooling system.
Good luck
MT