1988 Chev celebrity Vortec 4 banger. 2.5 I think. My friend sadly has one of these. If he pours fuel in the carb it will start and keep running. So Im guessing not the fuel pump. But it wont crank start. I thought Distributor module but if it runs ater starting I m thinking maybe not. Any Ideas out there?
you should use a scanner and look at the the crank sensor signal. it may have a weak signal until the rpms get up higher. Also the MAP sensor could be giving the wrong signal to the computer. (or may have a bad 5V reference signal to it) Start up fuel pressure might be low. Cycle the key on and off a few times to turn the 2 second prime to build up pressure and then try starting it. Measure the actual fuel pressure. it takes a little more pressure to start a cold engine than to keep it running or to start it when it is warm. You could look at the coolant temp sensor to see if it shows a good temperature reading.
when it won't start can you look to see if the fuel injector is spraying fuel while you are cranking?