RUNS ROUGH and Smells Like eggs

1994 s10 4.3 blazer. Runs really rough at idle. Even worse when in drive. When I take off from a red light it seems like it is running on 4 cyl. I put new plugs in, cap and rotor. I also put new egr valve in. What else could be wrong?

MORE: I also do have an exhaust leak from the crossover. The longer I drive the truck the worst it runs....

MORE: I also do have an exhaust leak from the crossover. The longer I drive the truck the worst it runs....

Check out the thread called "Carbon Buildup/EGR Probs ( 1 2 )" there are simular problems and solutions to what you are describing. Check it out it may be worth your while. I have been having simular problems with my 93 Jimmy.
Anyway, one of the things I have read is that it could be the CPI if you have the W series engine (High performance engine). I'll be checking out my CPI this week. Update on how you make out.

I have been reading the posts about the cpi, but I really dont know how to determine if that is bad or not. I do believe I have the high powered vortec with the high rise looking intake. I did already change the egr valve and the truck ran terrible as soon as I started it. I dont think the actual egr is the problem. I do feel like it is for sure exhaust related. When the truck is running really bad, it is almost like somebody stuck a banana in the tail pipe. If I Rev up the motor it will sputter and kinda clear out. The truck will run well when I am up to speed. Any more help would be greatly appreciated.

this sounds exactly like my problem last summer. the fuel inlet lines to the cpi were leaking. They are located on the driver side of the cpi and the cpi is actually in the intake manifold. when those lines leak they flood out the driverside cylinders, so check for wet spark plugs on driver side of engine. Good luck