Weird Idle Problems, brake causing higher & lower rev?!?!, Need some brainiac help please!!! Options

[jhaletama]

Hi guys,

Just had the head rebuilt on my 3sfe 1997 ST202 celica.

After being put back together couple weird problems.

1. If the car is started and just left to idle no problems, when you push the brake down it lowers the revs and as soon as you release the revs go up?! air con is off.

2. Once the car is warm and you drive it when coming to a stop the car wants to stall and die. air con is off.

3. when you drive the car at cold runs like a dream. once warm the above problems start. air con is off.

4. Car Temp gauge always sits about half way has done since i bought the car but lift the bonnet and you can feel the engine heat! it runs pretty hot. is this normal?

now the only thing i changed which is not from this engine is that black air valve on the top left side of the intake manifold. i accidently snapped the plastic tip so just grabbed another from a toyota camry. don't know if this will have anything to do with it or not.

when head was built, new gaskets from block up, new spark plugs, filters, oil, anti freeze.

any help would be greatly appreciated!!! Thanks again.

[azian_advanced]

for 1 and 2 - check your alternator.. it could be that the alternator is having a hard time providing current to the brake lights in the lower rpms, while the other components needed to keep the car running (ignition) isn't getting enough juice dropping the rpms lower and cause the engine to 'struggle'.

3 - replace O2 sensor

[jhaletama]

for 1 and 2 - check your alternator.. it could be that the alternator is having a hard time providing current to the brake lights in the lower rpms, while the other components needed to keep the car running (ignition) isn't getting enough juice dropping the rpms lower and cause the engine to 'struggle'.

3 - replace O2 sensor

Hmm, well the car is running on an iffy battery so could that be half my problem?? Also on the intake plenum top left if standing in front of engine there is a black valve with a vacuum feed on it, not sure what it is, i broke the tip of it so hose couldn't go on but i grabbed another one off of a toyota camry, would this have any effect ?