I had a previous post going, couldn't find it to bump it up so decided to start a new one seeing how the problem is still persisting.

I have a 1993 chev Blazer 4.3L Vortec "W" series. When I pull up to a red light or stop sign, the truck idles good for about 10seconds than starts to idle really rough and shake violently. Upon take off it sputters like fuel starvation or a bad misfire than takes off. The list of things that have been replaced is quite extensive.
-Spider Injection Assembly, lines & all (Replaced about 40k ago)
-Fuel pressure regulator (Replaced3k ago)
-EGR (Replaced 40k ago)
-Fuel Filter (Replaced 5k ago)
-Fuel Pump (Replaced 20k ago)
-New plugs, cap & rotor (Replaced 20k ago)

There's really nothing left to change other than plug wires which I don't believe have been done.Other than that maybe a sensor like an O2 sensor maybe? Winter is coming and want to use it for Snowboarding, I need to get this thing running right.

 

Was the fuel pressure regulator replaced because it was leaking?

If so, then you might need to remove, clean & reinstall the EGR valve. You don't need to replace it, you just need to clean the carbon from around the pintle and pintle seat.

When you reinstall it, use the Tomco or Help! screened gasket.

Also, plug wires are indeed a weak spot on these trucks - if they're not Delco and they have not been replaced in over 40k miles, replace them.

 

The FPR was replaced cause it looked like it had minor signs of leaking when I pulled the plenum off. I went ahead today and changed plug wires with some Delco's, air filter cause it was due time to be done anyway and saw that the air temp sensor in the air intake tube was all gummed up so I cleaned it with some CRC carb cleaner. Well not only did none of what I did make any difference but now the service engine light is on. WTF?
I also noticed that on the drivers side right below the middle plug wire there is an electrical plug that is cracked. Any ideas why now the engine light is on?