Please Help

I have a 1991 4x4 3VZ-E automatic. I have already replaced the plugs, plug wires, distributor cap, rotor button, air filter, fuel filter, pcv valve, TPS and checked for vacuum leaks. The problem that I am having is at running temperature if I try to start the vehicle it dies, I can apply gas to keep it running. Most of the time in the morning it will run for a little bit. If I come to a stop it dies, I have to keep my foot on the brake and at the same time continue to give it gas. I have also noticed that lately if I am going and just let off of the gas I can hear a relay kick in the dash. I traced the relay down and it is located above the ECU, its labeled circuit opening relay. This problem occurs regardless if the A/C is on or off. As of right now it does not have any stored engine codes before I think it gave me 41 for the TPS, I replaced it with a supposedly good used one with no change so I put the original one back on. I anyone has any ideas please let me know!

check your coolant level ... there is a sensor that will affect idle if the coolant level is low.