Hi, Im having problems with my 85 Firebird Trans Am, the guy i bought it from did a swap, so now its got a 305 TPI from an 87. It starts fine in warm and hot weather, but when its freezing or below it takes a long time to start i mean like atleast 10 mins and then when i do get it to run as soon as i even touch the gas slightly it will die, then if i let go if the gas quickly it will just make it back and idle again. if i go wide open right away it will go up smooth but 1/4-1/2 throttle is weird, i tested my TPS its at .60 at idle and about 4.3 wide open and it goes from .60 to 4.3 smoothly and gradually so thats fine. i think its my ECT? but dont i have 2? or something i need some help and opinions please

the original temp gauge in the car doesnt work anymore, so the guy bought an aftermarket gauge and installed it. It takes its reading from the very front under the throttle body in the manifold

 

in the front under the throttle body would be the engine coolant temp sensor. the engine temp sensor is located on the drivers side of the block, between the #1 and #3 cylinders.

If youre talking about below freezing temps, then yes, it will be hard to start without a block warmer. 87 should have a 9th injector on the drivers side of the intake manifold. its squirts gas into the intake to help start during cold temps. pull the connector and put an ohmeter on the injector. should get 3 to 7 ohms. any higher or lower and it should be changed.