Why do my revs go up when I brake?
The brake booster improves the master cylinder setup utilized to lower the pedal pressure required for braking. If the brake booster has a leakage, it allows additional air into the intake manifold. As a result, the air enters the engine and causes the revving.
Can a vacuum leak cause idle surge?
If an engine is not getting enough fuel (this is called “running lean”), due to fuel pressure (regulated by the fuel pump and regulator), restricted fuel injectors, a vacuum leak or really anything that throws off the fuel mixture going in to the engine, this can cause the surge.
What does it mean when Toyota pickup surging idle?
They are activated by coolant temp to open and close for quicker warm up. When they stick then you get this surging up to 1400 RPM or so then a rapid drop in RPM’s and the cycle continues as long as you are on the brake pedal! In other words it’s the IAC that’s bad. 7 people found this helpful.
Why does the idle surge when in neutral?
This went away the next day or so, but every time I’ve made that 4 hour drive, it happens for longer and longer each time. Now its really bad, and on top of the idle surging while the brake pedal is pressed, it ALSO idles really really high when in neutral and even sometimes surges but in fewer intervals when in neutral.
What should I do if my Toyota 4Runner Idles?
If the motor idles better replace the brake booster. A brake booster for a toyota pickup can be hard to find but you can also use one from a comparable 4runner. The only issue I encountered is the new booster made the brakes overly powerful and touchy.
Why is my Toyota 85 idling so hard?
About two years ago the brake booster on my 85 was not fuctioning properly. the brakes got hard and the idling of the motor surged in the same way you described to the letter. When I replaced the booster the motor returned to idling normally.