06 Corolla engine surge

[Katman]

Hi all, new here.

I have an 06 Corolla manual, which I bought new. Ever since I have had it the engines surges (hunts) and hesitates on light throttle setting, even at 60 kmh. The dealership I bought it through keeps telling me it is the fuel shut off valve and it is normal operation for this.

I have a good knowledge of engines, having built several engines for my Datsun 1600. To me this does not seem like normal operation. The test car I drove showed no signs of this as I am very aware of a cars performance. I want to go back to them again but need more information/ ammunition to back me up.

Has anyone experienced anything similar or knows the answers.

Cheers, Richard

[Suprathai]

If it surges and hesitates on light throttle, why would the 'fuel shut off valve' affect your driving? So at full throttle its got no fuel??

Tell them you believe that there is a vacuum related problem, and at the moment you think its related to the IACV (?) valve. Its basically attached to the throttle body and may just need cleaning out, or replacing altogether.

BTW does the surging occur at idle as well??

[Katman]

Hi Supra, it idles quite fine. It only plays up on light throttle and has done so since new.

The say that that the fuel shut off valve stops an overly rich mixture on overrun to protect the cat.

I think they are trying to avoid something which may be costly, but I dont have the knowledge to go back at them.

[123R-Prozak]

They wont be avoiding anything costly, If its an expensive part and an expensive problem to fix, dealers love it as they get paid for the big job from warranty.

They simply put the claim through, send the faulty item back if asked by warranty, part is inspected and then dealer gets paid. perhaps they are more so lazy? try another Toyota dealer? New car warranty is covered by any toyota dealer in the country. It's only when used car is the fact where you have to take it to the dealer u got the car from. Maybee say it's getting worse to the other dealer??

that might give the hint its a real problem not ' Road tested vehicle, found operation of motor under slight throttle to be normal operation due to fuel shut off valve "