93 Chevy S10 Blazer Running Ruff
 

I have a 93 s10 blazer, 4.3L, that is surging, running ruff, dies when stopped (sometimes), tries to take off sometimes (like the idle is to high). I've replaced the CPI (spider injection), fuel lines to the cpi, IAC sensor, maf or map senor, throttle position sensor, all the vacuum lines have been checked. It's not throwing any codes, like for the EGR or anything. If I unplug any sensor than the check engine light comes on. This is my husbands vehicle and he won't let it go. I'm at a loss. I have no idea what else it could be. We've had it 3 years and we've replaced all those, except the EGR, the fuel tank, fuel pump, fuel filter, knock sensor, new Y pipe, spark plugs, o2 sensor, new vacuum lines, new distributor and distributor cap, both engine mounts and transmission mount, and maybe more. It's been a money pit since day one. Any ideas would be appreciated.