Topic: doesnt want to idle right

[Thresher]

a while back my tps sensor went out on my 1989 toyota pickup 22re....now whenever i drive for a little bit and step on my brakes to stop my truck purrs good and sounds like its gonna die back and forth fast....and when i let off the brake its fine.....someone help me

[79coyotefrg]

replace your brake booster, that round thing between your master cylinder and firewall

[Thresher [OP]]

more info i forgot to put this is the first time.........it doesnt idle funnt when im 4wd and stepping on the brake

[Caboose]

vacuum leak? 

[yotatough]

I'm searching pirate right now, but I remember reading something about this awhile back. your idle needs to be adjusted (set a little to high) and the computer is cutting the fuel to the motor (only when in two wheel drive) then when it brings the idle back down it turns the fuel back on again over and over, mine dose this when not completely wormed up in the morning.

[yotatough]

sorry for babbling what I was trying to say is just adjust your idle down a bit.

[kneedownnate]

Werd, I did that on my 91 22re when I cleaned the throttle body and didn't set the idle screw right.  I didn't think my idle was too high, but that's cause it never stayed up long enough to sound high before it popped back down. 

[Thresher [OP]]

well yesterday i took my yota to a master of toyotas and we changed the pcv valve and i got a brand new air filter and its still doing the same thing

[LOL @ IFS]

Sounds like he's not really the master of Toyotas now, does it?

The solution to your problem has already been posted.  You have a vacuum leak, and it's somewhere between your intake manifold and your brake pedal. 

[Tallchevy]

I had this exact same problem on my 89. I checked the brake booster cause it only happened when I stepped on the brake pedal. The problem ended up being the idle air control valve was carboned up causing the ball not to seat right. It's part of the throttle body. I didn't take pic's but I took the thottle body off, removed the 4 screws. There is a cap that has 4 notches & a hole in the center where the ball seats. I used a screw driver to remove the cap. Count how many turns it takes to remove so you can put it back in the same spot when you put it back together. Remove & clean everything, even the coolant passages. A new throttle body is around $400 so I would try this first   

[ROKTOY829]

You didn't say if the guy adjusted your idle screw when he changed the pcv and a/f. Check it cause I've seen them get loose and cause a vacuum leak.

[Thresher [OP]]

well whenever i first turn it on it doesnt happen..until i drive for like 5 to 10 minutes