I have changed on my GMC the EGR valve the O2 sensor plugs and wires Point caps and rotor and the fuel filter changed . And then I got my GMC timed and after the timing was done my GMC started , backfiring , surging and when I hit the gas it will choke out or it doesn't want to go. Could the distributor be causing this problem? And when I take the hose off the EGR valve that's coming from the EGR vacuum solenoid there's no pressure in the hose. I was told if you took this hose off the GMC should start running kind of bad and then when you plug it back in it will start running smooth is that true? Can somebody help me?

 

well let me start with the egr. it only gets vacuum when the ecm tells the egr solenoid to open it wont ever see a pressure. so removing the hose between the egr and vacuum solenoid wont do anything unless other scenarios are met (i.e. throttle less that 40%, a set speed). the ignition is a different story, im not 100% sure whats going on there. but who set timing? did they unhook the ESC wire?

let me also ask why did you change the egr and O2? the issue you described could also point to a bad egr thats stuck open.

 

No the mechanic screwed up there. Changed the 02 because of reading on obd1. Was told to change egr.

 

I wouldn't look anywhere else other than whether the timing was done correctly or something was not connected, disconnected, broken when setting the timing.

Did you do it yourself or have someone do it for you? If someone else - take it back and tell them they messed it up. If they can't won't fix it - go elsewhere.
Do it yourself is not hard but read some threads on how - here's one https://www.chevytalk.org/fusionbb/s...php?tid/269357

 

How was it running before the work was done as compared to now?