I have a 93' Blazer, I have an issue where when cold and Idleing my truck sounds good. When it warms up if runs rough like it is miss firing. I have timed, Replaced: router, cap, wires, plugs, spider injecters, O2 sensers, fuel filters. Have checked the compression on all cylinders and it was good. Fuel pump was tested and had good pressure. I am stuck I don't know what to do from here. Any suggestions on something to check where and how is much appreciated.

 

*Moving to 1st Gen Tech* - As the description of the Gen Chat section states, technical questions belong in the appropriate technical section.

Is EGR valve functioning properly, not leaking?

When the fuel pump was checked, was the leak down rate monitored? You could have a leaking FPR.

 

How do I test the EGR valve to find out if it is malfunctioning?