1996 S 10 Blazer LT. 195000 miles. The miss only happens at idle when the engine is good and hot. The miss is worse when the engine is under a load. ie. when parked at a stop light with the transmission in drive and the brake pressed. There is no miss when driving down the highway or street. Just at idle. No SES light on. New wires, plugs, cat converter, cam shaft sensor, crankshaft sensor, MAF sensor.10,000 miles ago. (I installed a new rebuilt engine 10,000 miles ago.)

Any idea what it is? The IAC? MAP sensor? EGR Valve? Any help appreciated.

 

A miss when hot points to the ICM (ignition control module). I would recommend that you have the ICM tested (Autozone or Advance Auto should be able to do it for free) and when they are testing it, have them repeat the test at least 10 times in rapid succession. This will heat up the ICM to operating temps and should reveal any faults that might not be apparent at lower temperatures.

 

ok thanks for the response. how do you check the control module. Is it something that I can check??

 

You have to load it. Hence why I suggested you go to Advance Auto or Autozone.

 

The ignition control module checks out fine. Anyone have any other suggestion. Like I said in my first post it only does it at an idle when engine is hot, below 1000 RPM. It seems to be getting worse.

I have no codes stored. Could it be the idle air or the MAP sensor?