My totally stock '95 Formula has been spending a lot of down time the past few years since I was working out of state and driving my other car, but it has still been running great, smooth, and clean when I take it out. Now that I am just about to drive it cross-country for a major move back east in a few days, it suddenly starts acting weird today. It seemed a little rough idling, and running surprising rich -- unburned gas smell -- and although it seems to run strong and seemingly on all cylinders when I floor it, it now cranks but does not start unless I put it to the floor --- that's right, like a flooded carburetored car. Also a strong gas odor persisted after I shut it down at home, and I should mention that since I flushed the cooling system last month it seems to run alternately cool and then hot like there is air in the system. I don't have a clue what this new demon could be --- injector, EGR, OX sensor, optispark, etc. but I need to fix ASAP. Any help you can provide would be greatly appreciated. Thanks up front.

 

I would check fuel pressure at idle AND during a WOT pull

Bleed the cooling system. LT1 are reverse cooling systems and require bleeding if you "flushed" it

 

Putting the accel pedal on the floor while cranking puts the PCM into "clear flood" mode.... yep, just like a carb setup.

Leaking injectors, or a leaking fuel pressure regulator could cause the flooding problem, and will show up by turning the key to run, watching for the peak fuel pressure on prime, and watching how fast the fuel pressure drops wen the pump shuts off. Pressure should hold and drop slowly. Rapid drop = a leak somewhere in the system, or a bad check valve in the fuel pump.