I hope someone can answer this.. 1999 2 wheel drive 2dr blazer 4.3 engine. The blazer was was running when parked , and was only parked due to freeze plug starting to drip while running . Unfortunately my uncle let it set for 13 years. my nephew who is 16 , just got his license was looking for a vehicle and we thought this would be a good first ride for him. we pulled it out, put fuel down throttle body and it fired right up and ran strong until that fuel burned off , after doing this multiple times , decided it isnt getting fuel , checked out fuel pump and it was no longer any good , installed a new pump and still the same issue, We also installed a new Battery and have been keeping it fully charged during all of our testing and engine cranking . Yes we have checked the fuel pressure , it has 60+ lbs and virtually no leak down for 10-20 minutes. I dont think it is an SES issue either, when you pour gas down the TB the ses light comes on as it should while cranking and goes off immediately after the engine fires up and the engine runs great until the fuel you poured down the TB burns off. And you can keep pouring fuel down the TB and it will keep running until your stop pouring it in. So I know from checking the fuel pressure with a gauge that the pressure is good enough and it is getting to the spider injection unit , But does not seem to be getting past it into the engine , I also realize the spider fires through a ground signal coming from the ECM (computer ). I have have taken the computer apart and visually inspected both boards, internal ground clip, and lead from one board to the other. I could see no burnt or damaged components on the boards , no burnt smell at all and no corrosion on any of the plugs or pins.. Also the plug and pins on the spider injection unit are perfectly clean like new. Now what im starting to wonder , could the ECM lose its flash on just the injector pulse from sitting so long without a hot Battery in it ? Obviously im not a tech, just an old shade tree of Vehicles from the good old days. I do not have a scan tool or osciliscope..I do have a DMM .

 

There are two things to check. First would be the injector pulses from the engine computer with a Noid light. Second would be the amount of fuel being injected (if any) by a metered set of injection pulses. My bet is stuck injectors from old fuel and varnish. The computer does not lose its flash from sitting. The memory does not depend on power, that’s volatile dynamic RAM your thinking of.

The idea of a bad ECM/VCM/PCM comes up a lot here but is almost never the proble, although many get replaced.


George