Hi, I'm a newbee. I have a 1992 Pickup. 22re, 5spd, lock-out hubs, short box. Recently it has developed a problem. Any time while driving when I go to slow down and come to a stop when I apply the brakes the engine idle starts "bouncing" up and down. Probably from about 900 rpms' up to about 1100 rpms. When I release the brakes the idle returns to steady. I thought it might have been the check-valve in the vacuum hose to the brake booster. But I disconnected it, plugged it and it didn't change anything. So it seems to me it must an electrical issue that's happening when the brake switch is activated. I'm just not smart enough to figure it out past that. Any thoughts or suggestions are greatly apprieciated. Thank you for reading my question.

 

The skinny is that your idle is too high.

To get the rest of the story and how to fix it search for "fluctuating idle" and read until you get tired of reading. This is a very common issue.

 

Thanks, I have already drpped my idle and no changes. However, I just recently changed the head gasket. After reading up on your suggestion I'm wondering if I have the timing set a little to far advanced. I didn't set the timing with a light, I just made a mark on the distributor and engine and put the distributor back in the same place. I suppose after reading up on this that this is a very possible solution. If this doesn't take care of the problem I might also check the TPS and see if it,s a little out of wack. Thank you very much for the info. I'll let you know what I find out.