runs rough after warmed up

[bigblockchevelleman]

I have an 87 chevy silverado tbi 350   no codes , only flashs 12 new thermostat , new temperature sensor, egr valve seems to work had it off will work with vaccumm  and hold  start the truck runs fine after it gets heat in the engine starts idling rough , if you get to about 1400 -1600 starts surging and smoking , bring rpms above 1800-2000 seems to run better but still get smoke.  anyway to check map sensor ?  anyone have any ideas to what else the problem could be ?   thanks  steve

[VileZambonie]

Yes you can check the map sensor but first unplug the vacuum hose from the egr valve and plug it. See if it still does it.

[bigblockchevelleman]

think I may have found the problem  Bad IAC valve took it off last nite frozen up unplug when running makes no change. just got a new one gonna try it tonite