I bought an 87 Iroc z28 with the 350 and the guy said it had a problem starting and would leak fuel and die out then said the fuel lines were mixed up for return and the breather so it would leak from the canister. Switched the lines and solved the gas smell problem. Still hard starting and would die while in D or R. So I changed the fuel pressure regulator. Still idles weird at a light in gear and hard starting. Then tightened the throttle position sensor. What else could it be?!?