HouseCallAuto 11/23/2010This either has a bad ignition module or high resistance in the fuel injectors is shutting down the ECM injector drivers. Diagnostic tip: Verify the Purple/White wire at the Ignition (IGN) module carries a 0-5 volt square wave to the Powertrain Control Module (PCM) during cranking and running. This is the RPM signal the computer uses to operate the fuel injectors. This cannot be tested with a voltmeter. Must use a lab scope. If the signal is there and is a good signal then the engine will need injectors. One other test you could do is to remove the intake manifold so you can get to all the fuel injectors. This you can do with a basic ohmmeter. Read the ohms resistance at approx room temperature (so do not run the engine first) The fuel injectors should ohm out at 1.16 minimum to 1.36 maximum ohms. If they all ohm out within this range then it is not the injectors causing the problem. This injector problem was common back then on GM engines with multec injectors which this has. Another thing you could do is go ahead and replace the ignition module but it is not a sure thing but the part is fairly cheap and fairly easy to replace. As I said it will be one or the other but not both. So, that being said, decide which avenue to take first. There is not really another component on a 90 Lumina that can do this excepy maybe the PROM in the ECM but that would be very rare as I have never actually seen one fail and cause this but I am schooled to know it is possible. The PROM does not come with a replacement ECM. It is ordered separately from GM only, but don't even consider this as a cause for now.
vince^_^ 11/23/2010Did you also check the condition of your fuel pump and its relay? Also check the condition of all your fuel delivery system components for any restriction of your fuel flow, air filter (since you already check for vacuum leak) and check your ignition components if it produces spark to figure out what you are losing when it dies after it start ( if it’s your fuel or spark or air). Is your vehicle equipped with carburetor? If it is, you should check it to because the mixture and production of your air fuel mixture is the job of your carburetor (which is one of the components of your fuel delivery system).