Runs sluggish - Idles rough

92 chevy astro engine code W - 135,000 miles. Runs extremely sluggish after warming up. Plenty of pep while it's cold but after warming up it will barely reach 65 mph. Also idles extemely rough both warm and cold. We have replaced timing chain, cat. converter, muffler, EGR valve, plugs and wires, distributor and fuel injector. Wife is threatening to "cut me off" if this thing isn't fixed soon. Please help!

Don't feel bad, I have the same problem with my 1990 astro. Mine started that, now it won't go over 40 and stalls for no reason.

Did you check or replace your oxygen sensor? I am working on mine, and it appears to be something electrical. Maybe a fuel pump, or wiring. May be something electrical, I am getting weird timing problems. Replaced all that, but haven't done the ignition coil, that is what I am on now.

As a temp fix, try unplugging the map sensor.

Did you check your throttle position sensor?

Did you replace the spark plugs?

By running rough, do you mean that it shakes or shimmys, or do you mean, it wants to die or stall? Try the 1984/85 models. They have an old fashioned carb with only hoses to replace, and a mechanical fuel pump which is attached to the engine. And the '84 outlasted the 90!!!

Thanks for the quick reply. I'll be replacing the ignition coil tomorrow. Never heard of a MAP sensor. Where is it? What does it do? Thanks again for your help!