Have a 1989 K5 Blazer and the idle is a little high. At icy instersections, when stopped, the rear wheels want to push me through. How does one adjust the idle on these throttle bodied units?

 

It is controlled by the ECU. I would check to make sure that you do not have any broken/cracked/disconnected vacuum lines and that there isn't a gasket leak between the throttle body and the intake manifold (somewhat common problem).

 

Sounds like rear brakes aren't working ?????

 

agreed, mine did the same untill i redid my rear brakes...

I actually had to put it in neutral to stop, or 4wd(kept hubs locked in the snow).

 

There is a way to adjust it I will have to search for it and maybe link to another forum if it's ok.

 

People will argue and say this won't work or you can't do that only the ecm adjusts idle speed, but trust me it does work I have done it to more than 1 tbi and it won't screw anything up. I have done it on my stock 4.3 tbi I have done it on my 5.7 jimmy /holley 670 tbi and lots of others,if you need it I have a pic of where the idle screw is hidden on the tbi's
http://www.thirdgen.org/tpimod2

 

You can change base idle on just about any older setup. However, that is kind of just a bandaid. You haven't really solved the problem...

 

Well it adjusts the idle speed without the ECM correcting it so yes technically it does solve the problem but like I said some people always argue even if they have never done the procedure.

 

Assuming there are NO other reasons for the high idle, you would be correct. However, if there is a vacuum leak, adjusting the base idle will not fix the leak.