Rough idle problem?

95 blazer, 2 door, 4WD 158K miles
About a month ago I changed the plugs and wires due to a rough idling problem and it seemed fix the problem just fine. A week or so later I changed out the waterpump and thermostat because the truck was consistently running around 210 degrees. Once I put in the new WP and Therm., the temp runs at about 190 as it is supposed to. Now I am once again getting the rough idle probelm again (about 2 weeks after replacing the WP and Therm. The question I have is.....could the wires and or plugs have "cooked" in those 2 weeks while the truck was running hot? Should I just changed the plugs and wires again or shoudl I be looking for something else?

Thanks in Advance.
Greg

95 blazer, 2 door, 4WD 158K miles
About a month ago I changed the plugs and wires due to a rough idling problem and it seemed fix the problem just fine. A week or so later I changed out the waterpump and thermostat because the truck was consistently running around 210 degrees. Once I put in the new WP and Therm., the temp runs at about 190 as it is supposed to. Now I am once again getting the rough idle probelm again (about 2 weeks after replacing the WP and Therm. The question I have is.....could the wires and or plugs have "cooked" in those 2 weeks while the truck was running hot? Should I just changed the plugs and wires again or shoudl I be looking for something else?

Thanks in Advance.
Greg


have you cleaned the EGR valve lately? could be a small carbon particle holding it open.

also, has the CPI injection unit been replaced on that one yet?
this one is most likely the culprit. these genrally go at about 100,000 miles, the fuel pressure regulator starts leaking. the one in my 95 S-10 has however made it 176,000 so far. check the fuel pressure, should be 58-64 psi with the key on and the engine not running. then start it, the pressure should fall 3-10 psi. if the pressure is too low,( and your fuel filter is recently new) remove the upper intake plenum and inspect for fuel leakage. both sides of the lower intake should apear the same. be aware you'll need a new plenum gasket.

that should get ya started......good luck

thanks cobra....

I have cleaned the EGR valve preetty recently (about 2 months ago) and I did have the fuel injectors replaced about 2 years ago. I will check the fuel pressure.

Thanks,
Greg