I have a 91 tpi z28 when you first start it runs great a minor miss at idle thats it it starts great and accelerates fine. 5-10 minutes of running it idles like crap and when tyou go to accelerate it is a total dog. The car has a new fuel pump and filter fuel pressure regulator. plugs wires and cap rotor. It runs great cold.

 

Check coil output, ign module and pickup coil

 

thanks how do I check the ignition module

 

I had the module and coil tested the tested ok. could it be the magnetic pickup?

 

if you figure this out please reply I have the same problem with my formula 350 I would like to know

 

When it gets to regular operating temp the ECM begins to use the O2 sensor to adjust the air/fuel ratios. Are you getting any O2 sensor codes? Try disconnecting the O2 sensor and see how it runs when warm.

 

Do you know what is the regular operating temperature?

 

Between 190 and 220 I think. Depends on the car and setup etc.

 

I'm new here and have the same problems with my 92 305, if it runs better with the o2 sensor removed, can it be left out?