My 1984 C4 stalls at very low speeds, usually in stop'n'go rush hour traffic. It only occurs when the automatic transmission is in Drive. The hotter the temperature (both air and coolant) the worse it is. It idles fine in N or P. I have had the TBI adjusted and fuel pressure checked. Is there anything else I should do or should I go straight to replacing the factory TBI with a Renegade or X-ram system?