I have been having the same problem with my Blazer the EGR valve. I have replaced it and for now it is working fine. I have also replaced the following things since I bought it about 3 months ago: Air Idle control value, CV joint on the passenger side.
My main problem at this time is that the 4x4 was working before I replaced the CV joint on the passenger side and now it does not want to work. The transfer case is working and so is the drive shaft, but the front wheels don't turn. Can anyone help me or give me a hit to what is going wrong. Please e-mail me at royalslimmer@netzero.net.
Steven, around this time 93 or so GM had some injector pack regulator internal leakage problems and would cause the motor to start making carbon and in turn the carbon would turn loose and stick the pindel in the egr valve so if the regulator is leaking the EGR valve will cause an SES lamp and the motor to miss and exhaust black smoke due to the carbon. The new valve will also do the same until the regulator is replaced. This is with the vin code (W) (4.3) motor only. About the front drive axles you prob. knocked the power wires off the frt diff 4x4 actuator motor. Hope this helps.
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