92 S10 2.8 t5 trans. Here's the deal. Runs rough like a dead miss on a few cylinders. Only above idle. So here's what I have replaced. Coil plugs wires cap and button. It was due for a time up anyways. Still rough. So I started actually testing stuff. Found TPS has good 5v and good ground. Signal wire is at .4v at closed. And 2.8v at WOT. The sweep was kinda jumpy and sporadic. So I replaced and patted myself on the back. All to soon. Same stuff. WOT is still 2.8v not jumpy on the sweep though. So isolated the circuit and checked for short to ground. Tested good. Check ecm powers and grounds. What's the next step? Or just plain bad ecm?

 

I'd run a compression test on all of the cylinders.How many miles on your S-10?

 

Have you checked fuel pressure?

 

if you think the tps signal should be 4.8 volts at wot...maybe you should ohm check the wires