At startup time (RPM up & Down)

[corolla1998]

This always happens at the startup time (when cold), the RPM will go up and down for a few minutes, until the car gets hot, then the RPM drops to a normal REV.

Would there be a senser that needs replacment, I recently purchased the vehicle and don't think this is normal.

thanks

[Bdub215]

Possible intake manifold gasket.


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[corolla1998]

is it a known problem with these cars, I would of thaught a worn out senser that connects to the trottle.

thanks for your help

[Buurin]

I also had this happen the first few days after swapping in a lightweight flywheel...

[corolla1998]

what was the solution, was it the gasket (intake) or the problem just went away.

thanks

[Buurin]

For me, it just went away...

[expertmax]

Try cleaning the Idle Air Control valve and replace the PCV valve, it's cheap and probably has not been done.