I have a 91 GMC sonoma /w 4.3 v-6. At start with engine cold, it will start but runs very rough and will not idle till it warms up. After warm, it seems to run very well except for what seems to be idling a little slow. Has been tuned with plugs and dist cap and wires and such. Has a new tps and map sensor. Have replaced idle air control as well. What should I look at next.?

Is the check engine light on?

No check engine light. After posting ?. I cleaned egr and throttle body and ran some cleaner thru vaccuum lines. At present , all is good. Just hope it holds. Thanks