dasch

I just completed doing a head gasket replacement(my 1st time, just a newbie here )..... no leaks, starts right up, BUT it idles high(1500 rpms) at startup then keeps dropping and dropping slowly until it idles so low that it stalls. Do you think my problem is with the vacuum lines or the TPS or something else?


90' 4runner 3.0 v6 3vze 4wd

sherri_girl

Is your engine check light on?

dasch

No engine check light, it just idles lower and lower until it stalls.



90' 4runner 3.0 v6 3vze 4wd

sherri_girl

You'd think if it was TPS it would trip the check engine light, but that would be too easy. Could be a vacuum line or maybe EGR?

dstrick32

Have you tried adjusting the idle jet screw? It's a brass screw inset at the rear of the throttle body, can't miss it if looking. Screw in to decrease and out to increase. Best done at operating temp!!

dasch

I found a plugged vacuum hose, fixed that and that solved that problem, but NOW my idle drops when I apply the brake, so much so that it even stalls sometimes. What would cause that? Can I open up my brake booster? If so how and what should I look for because I am thinking that maybe my problem is there.


90' 4runner 3.0 v6 3vze 4wd

wrenchmonster

Brake boosters can go bad. Pinch off the line too the booster and see if your problem goes away. If so, you probably have a bad booster. How does the pedal feel? Haven't seen one on a Yota, but this is a common problem on the Scout IIs I have worked on.

-Wrench