BAD BRAKE BOOSTER.....Yep, thats what it is. For a long time I never really had a good solid idle. I did'nt want to throw parts in it to find it so I looked for vacuum leaks. I sprayed intake cleaner on everything that was remotely linked with a vacuum or air. I could'nt test the brake booster any, but when I depressed the brake pedal, my RPMs would fluctuate up and down and while driving the car would stall and cut off while slowing to take a curve. I got my car to the end of my driveway which is about 100 ft. and cut off the car. I then disconnected the booster line at the check valve and plugged it with a 10 guage wire nut real tightly. Started the car up and went for a ride down the driveway.....NO bumpy idles...NO jumping RPMs and no stalling. Sure, it was like stopping a tank, but it told me that it was a bad brake booster. AND...the engine idled at a ROCK STEADY 1100 RPMs with absolutely NO surging, skipping or lag. It idled like you wish your car would and I could'nt even detect the slightest skip ANYWHERE. Alas, I had to put the booster line back on til I get a new booster. Hey, the booster is the original and 15 years old. I got my moneys worth off it. Hope this helps someone else.

Ken

 

yep happens often

ppl should be checking these things

if the booster doesnt hold vacuum for a good while after the engine has been shut off and there isnt about three good pumps of vacum left in it still then its junk

can cause all kinds of problems with how the engine runs yep

good luck