[rfmaster]

Originally Posted by WestButteTruck

or maybe something bigger, like no oil pressure caused the relay to shut down fuel.

This will only happen if main FP relay, which is controlled by ECM, is off. The oil pressure switch contacts are normally open (NO) when there is no oil pressure. GM put two set of contacts to keep FP operating just in case if FP relay fails for some reason. If you have oil pressure it should keep oil pressure switch contacts closed and FP will continue to operate. ECM has no oil pressure input so it will keep FP relay contacts closed even if there is no oil pressure in the engine - this is normal during initial cranking as it takes time for oil pump to build up oil pressure in the lubrication system. FP relay functionality is verified during POST sequence - it is important to make sure that elements in fuel control system operate before troubleshooting.

//RF