Car revving when starting or idling sometimes. i was told it was a vacuum leak but i cant find any vacuum lines. can it be some kind of sensor im not seeing?

TOYOTA maker.
Toyota Land Cruiser Prado<<<<<this car?
Gen 3 Cruiser. with 4 petrol engines then.
no country told and is not USA car. we know that, but where? first sold
or VIN/
no engine told v6 size? 3.4 or 4.0L V6????????
wiki says the 3RZ-FE engine<<<< this?.for 2004
my guess ,is huge vacuum leaks.from lots of hoses even brake booster Vac leaks or hose never connected first.
IAC stuck open
TV stuck open on TB or gunked open
cutting out means stalling or just spark misfiring/?

getting too much fuel ,proved how? just RPM???????
the engine uses AIR, and this are he EFI adds fuel to mach air. mass.
that is how EFI works (be it mAF or MAP based)
online searching snows MAF sensor part of the TB.
some cars have idle only mAP sensor, but we have no books on this enigine.
let me explain MAF. mass air flow sensors
it measures ever microgram of air sucked in to the engine
the MAF tells the PCM this and PCM injects on mass air flow measured.
if you have any kind of vacuum leak the engine goes lean and slows DOWN LEAN BUT NOT IN COLD ENGINE STARTUP ENRICH MODE.

but not all engines witH MAF, SOME HAVE AND IDLE ONLY MAP SENSOR THAT IF VACUUM LEAKS HAPPEN THE ENGINE SCREAMS
KNOWING these to things, vacuum leaks
or in the MAF world UNMETerED air flow leaks.must be repaired.
all vacuum leaks are bad. besides, IAC allowed.

Check vacuum lines. Check idle control senser check air control senser. If it had a MAP senser check it. For senser unplug them while running, should change performance if not have that senser checke. Vacuum leak will not change when unplugging air control senser.

If it stalls when the brake lights come on then the idle is too slow. The high amps of the lights will load down the engine and lowers the idle.

Sometimes that's caused by a vacuum leak near the manifold area.

Sometimes air in the coolant will cause an idle problem. Air will keep the air temp sensor from sending proper info.
Hope this helps.
Sometimes that's caused by a vacuum leak near the manifold area.

Sometimes air in the coolant will cause an idle problem. Air will keep the air temp sensor from sending proper info.
Hope this helps.

If you are losing Brake Fluid, do not drive this with the engine revving. Not sure what you have the leak from; but a bad Brake booster can cause only a Vacuum leak, not a fluid leak.

If the engine is revving, do not drive. Start the engine, then take a spray bottle of water and mist the intake gaskets, vacuum lines and Brake booster. A leak will pull in water and change your RPM or stall the motor. When you find out where the leak is, you can fix it.

Some of the other symptoms should clear once the Vacuum leaks are found with the exception of the Brake fluid issue.

vacuum leak or blocked filter is more likely the problem, idle is controlled by the vacuum. if its losing vacuum it will not hold the valve open to let air flow though. look for cracked or split vacuum lines. can even be a damaged diaphragm, not holding.

Check the vacuum hoses for leaks. Follow them around and make sure they're all connected and not worn out to where they had fallen off due to the hoses being old and worn out. Take some soapy water in a spray bottle and spray mist the intake and see if the idle changes. Check the big hose coming from the brake booster to the intake and make sure it's connected and in good shape. Basically check everything for vacuum leaks. It sounds like that's what you're issue is.

a number of possible solutions, including a vacuum leak (check hoses, use a spray throttle body cleaner o9n the intakie manifold looking for leaks), or the Idle air controller is dirty or defective, or the throttle position sensor is bad. Do you have a check engine light?

Yes it could be a vacuum leak at the intake manifold, could also be the MAF sensor (especially if you use a gauze/oil air filter).

go to autozone.com and register for free. You will then have a full free online repair manual with step-by-step directions, diagrams, troubleshooting, testing, replacing, and more. As an automechanic myself, this a wonderful site.

This Vehicle needs an Idle air control/Idle speed motor. Good Luck