1988 Buick Skylark 3.0 litre

This morning, car started up cold. It ran for approx 3 mins and then abruptly stopped.

I heard a hissing sound and followed it to a filter? on front of fuel rail. Located and replaced a damaged O ring between filter? and fuel rail.

Pulled spark plug from #1 cyl. Dark chocolate coloured deposits at normal amounts of deposits. Proper gap indicated is .45 inch. This spark plug was gapped (worn) to .58 inch. I shall replace them all before restarting.

changed spark plugs yet hissing persists at front left of fuel rail. Car seems to run fairly smoothly. There is a haevy tick or perhaps a knock in front Valve Cover area to the left of oil cap.

Diagnosed puter, 2 codes other than code 12 a 3 and 2 and a 4 and 2 diagnostic. 3 and 2 is EGR ? I believe is a chronic reading in diagnostics.. 4 and 2 is ignition control? Possibly requiring new ECM? or?

Again the car fires, runs for a minute or 2 and then just abruptly dies.

suggestions? shall I test spark for inconsistent spark?

i'am an automotive tech and i will try to answer your questions the best i can #1. addressing the glow muffler or cad glowing means motor is running to lean. will cause extreme heat #2. is EGR stuck in the open posession that is not good must be closed with no noticeable leaks if you can keep it running long enough spray carb cleaner around it if idle runs up that is a leak need to fix.#3 you say you hear a hiss you need to find it againg spray carb cleaner around where you hear ir again if idel runs high that is a leak it needs to be fixed. vacuum leaks are one of the number on causes of engine failure. the map sensor controls the fuel ratio and if there are vacuum leaks it also won't work right because it also runs off some of the vaccum and electrics of the car you should only use heat in your car it comes in a little yellow bottle some of thoes cleaners will do more bad than good. also check your fuel pressure if you can get hold of a guage. all these things i have explained will cause a lean running condision whih can damage the cad and cause it to pluge up causeing back pressure in the system and can make engine stall . hope this helps there is just too much to explain here i will check back in a couple days.

I believe the hissing sound is coming from the fuel pressure regulator. Should I be able to blow through it one way or the other? I cannot blow through any of the three holes now.

With fuel pressure in gasoline engines. Could the fuel pressure regulator be supplying enough fuel tot he rail, allowing enough for initial startup and a minute or two of run before the fuel pressure to injectors might drop enough that they would cease to function and the engine would abruptly die? Or am I thinking too much along the diesel engine logic?

Spark is right colour and it is consistent. It seems to want to spark as it dies. perhaps then ignition control module is fine and the ECM doesn't need to be replaced?