1994 Chevy Blazer. 6 cyl

2 weeks ago I replaced the Brake Power Booster and Master Cylinder.

The very next moring while at low idle the car started bucking, meaning it was acting like it was getting gas and not getting gas repetitively.

One guy said it was the EGR value. So we cleaned it out. Same problem. So we replaced it a used one. Same problem.

Other info:

The car starts up fine. After about 5 minutes of driving, it will start acting like it is getting gas and not getting gas. When it happens I usually shift into a lower gear so the engine runs at a higher rpm and after about 5 minutes I can shift back to drive or overdrive and be on my merry way.

If I am in traffic, and the problem starts, it will stall at every stop. I can restart it, but it surges until it finally recognizes that it is getting gas(me pressing the pedal down)and revs up and I have to peel out just to get going, since I have to put it into drive at a high rpm. It will behave like this for about 5 minutes, by this time I am back on the Highway where I run at high speed and revs.

What is wrong? Did I disturb something when I changed the Brake Power Booster and Master Cylinder out?

 

Very possible. Check the vacuum line from the engine to the brake booster. This is a huge vacuum leak and all that false air will screw with the engines performance.

It is also possible that your disconnected your IAC. Idle air control, it controls the engine idle at low speeds and idle. Verify the wiring is still connected. Are you getting any troulbe codes?