ml30306

I used to own a 2000 Lexus ES300 on which I uninstalled the idle air control valve. I now own a 2004 Lexus ES330, can 120,200 miles, and was looking to do the same.

When I cold-start the engine the RPM's jump to around 2000, not sure if this is related to the IACV.

The lay-out on the ES330 looks different, and I can't locate the IACV. Has it been moved/re-designed/eliminated?

808mcv20l

I don't believe there is an idle air control valve for cars that are fly by wire.

starting 2002 they moved from cable throttle to an electronic one I believe so there isn't a need for an IACV any more since they can control those functions via the new throttlebody.

ml30306

Hi, thanks for the fast reply. In order to control the RPM jump on cold start - does it then need to be electronically re-programmed?

808mcv20l

I don't think that the ECU would need re-programming...

if your idle is bad that would be related to other issues such as a vacuum leak, dirty throttlebody, bad plugs/coils, bad injectors/pump, dirty air filter, EGR valve, etc...

If I were you I'd start off with changing the Air filter and cleaning out the throttlebody first, if plugs are old, change them. Do the basic maintenance first.

Rarely is there a problem with the ECU itself that is unless you have a model that was notoriously bad like the 92-96 generation with capacitors that would blow.