92 Chevy low idle/big down problem

[Edrowski]

Alright like title says I’m having a issue where when I’m backing up and let off the gas it’ll act like it’s bogging down about to die then it’ll idle back up to normal and when it bogs down you can hear like a noise like the motor is shaking or knocking or something. It does this going forward when I let off the gas it’ll idle down low for a second. I’ve replaced the pcv valve, grommet and tubing but nothing. I’ve searched everywhere on google and I can’t find anything. It’s a 1992 k1500 with the 350. Any advice will help thanks. ( I can try and record a video of it if that could help diagnose it)

 

[skylark]

Removing the idle air control motor and cleaning it and its passages extremely well. Then open up the throttle bores and clean down there. When you get done with that take a nice soft toothbrush and clean the faces of the injectors. Do that and then get back to us.