Engine hunting under brakes (no vaccum leek detected), high idle......

**LittleMissToyota** · 01-03-2012, 11:55 AM

Hey everyone.

Just got my Caldina back on the road and I am having a little teething problem.

When pulling up to stop (doesnt do it when just slowing down) my engine will hunt, but if I take my foot from the Brake pedal and put in on again it does it once then its fine....
Have sprayed around all the vacuum lines to the intake manifold (when the car is running obviously

) and there was no noticable difference.
Have tried resetting the ECU, and nothing.

Has anyone had a problem like this?
Im wondering if maybe its a bad earth or something but I just thought I would put it on here incase anyone has experianced a similar problem.

I also have a problem with my idle, I cant adjust it so its any lower then 1200rpm......

Thanks

**RT40Corona4AGTE** · 01-03-2012, 07:24 PM

I am guessing your brake booster might have a leak and that is leaning out your mixtures causing it to hunt. It also could explain why your idle rpm is high and not able to be brought down.

As a test, I suggest disconnecting your vacuum line to your brake booster whilst the engine is idling, plug it and try to adjust your idle. If you can bring your idle down, then its a pretty good sign it is a faulty booster/cracked line to booster/etc. Dont drive with it disconnected though, you will still have brakes, but it would not be as 'nice' a feeling on your brake pedal :-)

**4th surf** · 02-03-2012, 11:07 PM

Been a while since I've worked on a Caldina (like 6 years) as there's 2/10ths of 3/5ths of bugger all of them over this way. Seem to do only Toyota Surfs this day and age.. Ok find the power steer pressure line and follow it. Now either on the pressure hose or pump or steering rack there will be like a sensor or valve which has two "Vacuum hoses" attached to it. This is like a pressure valve between either the air flow meter of MAP sensor depending on which model you have. This is the "power steer idle up" and the hose side is made of plastic. These break and then cause a "suck in" of unmetered air which in turn causes the idle speed to increase to roughly 1200 as you've described. It's there to increase the idle speed when you go to full lock at idle speed to prevent stalling when the p/steer reaches full pressure. Now some superglue or Sikaflex may be your friend to glue it back together or a trip to the wreckers to pull one off a Corolla. Failing that I can find you a part no so you can go to Toyota or Amayama and get a new one. Will need Frame and model numbers off the car

**LittleMissToyota** · 12-03-2012, 09:12 AM

Hey guys, thanks for the responses.

On the weekend i stripped and cleaned the spare throttle body i have and cleaned up the ISCV. Upon removing the t/b off the Caldina and stripping down the ISCV i found that the bearing had seized.

Long story short fitted up the cleaned up t/b and she is all good now, no hunting and is idleing properly.

Guess i had better pull my finger out and do a members ride thread now