I have a 1992 alumina that misses and stalls after it warms up. I have replaced coil packs read the codes replaced MAP sensor (Wichita code called for. Now its just reading 12 12 12 12 12 ect. And still running no different does any one have an idea?

replace fuel filter.. i hope that solves the stalling.

try fuel injection cleaner too on 1/2 tank of gas like Chevron techron.. good luck

Possibilities: Oxygen sensors ,fuel pump, valve springs, pickup coil.

I'm assuming you have a 3.1/V6... replace your crankshaft sensor... when they go bad... they fail when the engine heats up... after the engine cools down, you can start and go again... eventually it will fail altogether... they're cheap... your car is a '92... even if it doesn't solve the problem, it's a good idea to update it... You can get to it from underneath, rear of block, 10mm, 1/4 inch socket w/extensions, 1 bolt holds it down... be careful with the connector, it's old, it may be rotten/brittle. ----- While you're in the neighborhood, above the CSS is the Knock Sensor, if it goes bad, or fails intermittently, your coil pack won't get juice... wouldn't be a bad idea to update it as well, same goes for the connector, be careful. ----- ...check all your wiring, vacuum lines etc, in the process... rubber, insulation, plastic, etc... gets brittle, cracks, etc... with age, heat, grime, etc... ----- code 12 on your computer is just the computer saying "hi, I'm working"... if it just keeps flashing 12, you have no codes stored. A bad O2 sensor would store a code. Get a Haynes manual, it will tell you how to read your codes, and explain what they are. happy holidays! - john b.