Car revs on it's own

Shurwhynot

I'm driving a '00 Seat Leon 1.4. Recently i've noticed that when i start the car, it revs away on its own. This also happens when i stop at lights or am parking...the engine revs away without me touching the accelerator.

Any particular reason for this?

mikkael

There are quite a few possibilites.

Idle control valve needs cleaning / accelerator sticking / emissions probe ( lambda ) feeding false info to the computer ( ECU ) / ECU defective ...

There's also the throttle position sensor, crankcase sensor, mass airflow filter ( maf ) and lots of possibilites of too much air or fuel. It could also be related to the movement, though I think that would manifest itself more in the car conking out.

At least being 00 it should have decent enough diagnostics.

Good luck,

Tony.

mickdw

all of the above but I would first check for cracked air intake hose between the MAF and the trottle body.

enda1

Air con and power steering can cause engine to rev too without accelerator being touched.

Marlow

MAF (mass-air-flow sensor) would be a common problem and can easy be tested.

In for example a BMW, you can disconnect the cable to the MAF and it'll asume default values then. So should it stop doing funny things after you disconnected your cable, it's the MAF.

But any of the above can really be the case.

/M

crocro

possible loose or disconnected vacuum hose.