So, just as a refresher because I do not have a garage yet, I have a '98 2WD Blazer w/ 171000 miles on the odometer. I just recently purchased this truck and since this purchase I've replaced and cleaned a lot of engine parts (I'm about ready to start on the chassis).

When I bought the truck one of the first things I noticed was how rough the engine idled and almost stalled sometimes at intersections. I thought a few adjustments and I should be fine. Well, I've cleaned the MAF, IAC, throttle body, EGR valve, distributor cap and rotor (dielectric grease was applied afterwards), replaced the PCV (it was clogged completely), replaced a few collapsed vacuum hoses, flush the cooling system (it's amazing the truck was running with all that stuff circulating through the system), replaced the thermostat, replaced the spark plugs, and ran some sea foam through the brake booster vacuum line, put some in the gas tank, and finally some in the crank case (will do oil change in about another 50 miles or so).

So, other than replacing the plug wires, distributor rotor and cap should there be something else I can do which might help smooth out the idle? It does idle and accelerate MUCH better after all this work but not as smooth as I thought it should now (then again, it just maybe the nature of the truck and I'm used to other cars).

I even thought about the spider injector assembly but I haven't decided on whether or not I want to just clean out the poppet valves or replace the whole assembly. I don't have the funds to replace it now but I might in the future. So, I thought for the cost of a few new gaskets and some cleaning fluid I could clean it well and see if that doesn't help the idle issues.

Oh, and when I cleaned the IAC, I noticed how caked it was with ? deposites and I wasn't sure if I should just replace it rather than clean it. It does seem to be working because the engine will idle somewhere around 1800 rpm if I disconnect it.

Ideas? It's idling at around 550ish rpms w/ no AC on.