May be someone could resolve my problem. When I drive in 'stop-n-go' mode (traffic jam) engine RPM goes down to almost zero under braking then back to idle speed. Its very annoying (sometimes its stalls). Engine was rebuild two weeks ago.

Thanks

 

vacuum leak

 

If it does this only when braking, it probably needs a power brake vacuum booster, which is broken and causing a vacuum leak.

 

Thanks. I've changed it already. No diff at all. Could distributor be the cause?

 

Maybe, except that it doesn't change when you use the brakes.

We're assuming that your spark plugs are good, plug wires are good, and so on; that is, the engine runs right for the most part, it just has trouble when you push the brakes.

 

Yeah, all above mentioned is new. No problems with engine in other conditions (good acceleration, perfect start, etc.). No problem when I brake from average and high speed. Doesnt stall when I press the brake pedal when engine is idling.

BTW: Tranny engage next gear (1-2, 2-3) on 3000-3500 RPM with WOT. I want that level to be 4000-4500. How can I achieve it?

 

Well, then you probably have a problem with the Idle Air Control. It's on the throttle body, and probably needs to be cleaned. Do a search on this forum, it is talked about often, and there are pics and step-by-stpe instrucitions.

The transmission shifting thing means the throttle valve cable needs to be adjusted. https://www.thirdgen.org/newdesign/tech/detent.shtml

 

Two ways to to overcome the early shifts are the B&M govenor recalibration kit (from summit, about 30 bucks) - you'd have to bring it to a transmission shop where they'll have some time (it's trial and error).

Or - you can get a transgo shift kit and just upshift yourself, bringing it back down to 1st or 2nd when at a complete stop.

 

The IAC could be it, or the hose going to the brake booster. Pop the hose off, plug it with your finger, and blow through it. If no air comes out, check the IAC for carbon.