Very Wierd problem

Have a 1994 Buick Centry. 2.2L 4 cylinder. 123k miles. Recently when I started the car the fuel pump made a rather low grumbling noise instead of the high pitch whine. Shortly after (like 2 miles) the car just stopped. Changed fuel filter and relay. This didnt help. Then changed the fuel pump. This didnt help either. Started to do voltage checking had full system voltage to the pump, so I swapped the pump agian thinking the new one was defective. Agian this didnt help. At this point if you can get the car to start it runs great until you shut it off. Once you shut it off when you turn the key on it will not engage the fuel pump. But can run direct 12 volt to the pump and it works. But will not run through the system wiring harness. Even clipped the harness at the pump and spliced in a new one. I am starting to wonder if the ECM has/is failing or if there is some other bizzare problem. Anyone else run into this? The pain of it is, its a intermittant problem. So if its a broken wire it would almost have to be only slightly broken and prone to road vibration and or heat soak when the engine is off. The engine light does not come. Tried to retreve trouble codes from computer, it came back clean. Is there a specific spot I should start to look? Thanks E-mail is [email protected] if there are any specific questions or (hopefully) answers.

Have you checked the oil pressure sending unit = Many GM's feed the fuel pump via a secondary contact in the oil pressure sending unit which closed when the oil pressure exceeds 6 psi. Fuel pump operation requires both a permissive from the ECM and the oil pressure sending unit to run.

Hope this helps

Opps, I forgot to mention that I did change that also. Didnt help, which is really starting to sound like ECM or some broken wire. One of those 10 hours to find and 2 min to fix type things.
Thanks.

anyone know if these cars have an inertia switch - many cars have an intertia switch to kill the fuel system in the event the car is in a wreck.

Otherwise, I am lead to believe bad wiring or bad ECM as you.

I had heard some of them had intertia swtiches so I spend a couple two or three hours tearing the interior apart to see if there was one. Got all the way up to where the wireing went up into the dash and never found anything. So if there is one it must be mounted in the dash, which seems like a wierd place to me. But who knows.
Thanks for the reply