I have a 94 s10 blazer 4.3L Vortec "W" VIN Code. Just bought it two months ago. It's not starting at all anymore. It started with chugging and stalling out. Now only starts with starting fluid sprayed directly on the intake. I have replaced several parts on this in an attempt to fix it and am stumped. My SES light works, but has not thrown it at me as of yet. Getting rather frustrated with it. Lets start with the replacement parts: Fuel pump, fuel filter, fuel regulator, distributor cap, rotor, Ignition control module, coil, air filter, throttle position sensor, map sensor, plugs and wires, and an alternator. Again its not throwing any codes and the CPI was checked, its working well. Have spark, fuel, air, and great fuel pressure. 55-60 psi on start, 50 on idle, when it will actually stay running. IF I can get it to start w/ starting fluid, it will stall unless revved up to 2000-2500 rpms till its warmed up then will idle fine for about 10-15 min. Then it seems to get hot and stall out again. Will start up immedietly and stall aprox 2 min later. And again, if I haven't said it yet, not throwing any codes. It has been checked by 2 mechanics in a shop, 1 back yard mechanic, and 2 backyard mechanic family members. We are all stumped! Any good suggestions would be great. I have been at this for 4 weeks now! Thank you!

 

Have you cleaned the EGR valve? Checked and verified that there are no vacuum leaks?

 

I have checked and cleaned EGR Valve, replaced the gasket with a clean screen gasket, and no vacuum leaks. I did also check the Charcoal Canister and the purge valve. The purge valve and canister are both keeping more than adequate vacuum. The reason I mention the canister is, its missing the filter on the bottom. I don't know if this would cause a problem or not, the filter is on back order.

And I forgot, we replaced the temp coolant sensor as well.

On a side note, I bought the blazer 2 months ago, and I was told a week before I bought it, the exhaust system was replaced front to back. I am not a mechanic by far, but am learning rather quickly a lot about my blazer and different parts of it. I am certain the extact details of the exhaust replacement. I can't help anymore on that.

If I get an answer from the next shop its going to, I will post further.