V6 surging

[zroleak]

I have a V6 Camry with 92K miles. Car starts surging at various speed at light throttle input. Toyota dealer did the diagnostic check and no code pop. They think it the throttle assembly might be bad. For $912.00 new throttle assembly and $90.00 for install.
Dealer verified fuel presure, MAF, TPS and throttle sensor are okay.
Are there any V6 owner out there with this symtom and what was the corective action???

thanks.

[marc780]

Maybe your throttle position sensor simply needs adjustment! I have an '02 V6. And one time i cleaned the throttle body, and after i did this, it idled with the same symptoms you have. So trial and error i found to adjust this sensor (the one with red dot by its name in the image below).

Just loosen the two phillips screws. The screws hold the sensor on through slotted holes in it. These slots allow the sensor to rotate just a little. And if you rotate the sensor, the idle will change. Maybe enough to fix your problem.
You will need a stubby phillips screwdriver because no other tool will fit. And press hard on the end of the tool as you loosen so you dont strip them out. Loosen the screws only enough to enable the sensor to rotate! (Its problematic to put the TP sensor back right if you take it off). Rotate the sensor and see how your idle changes. so try adjusting the idle and maybe you can make the problem go away. Worth a try.

[johnnyzee]

i agree with marc780, check your TPS. from my knowledge of honda and mazda, TPS's are not sold separately so they try to get you to buy the whole assembly, find an old one from a junkyard or used parts dealers.

[zroleak]

Thank you marc780 and johnnyzee for your suggestion.

In marc780 comment, you cleaned the throttle body assembly. So I did the same thing. When start the engine, it throw 4 codes, 102, 112, 2102, 2113. Car now idle rough. However, the car runs better and no more hesitation or surging. I didn't readjust the tps at all. it still have the yellow paint mark intact. For curiousity, i checked on these four codes and only could identify the first two, 102 and 112 both related to the MAF sensor. Once the code is clear, the car idle like it a new.

So again, thank you both of you for the suggestion and comment. It is still too early if this solve the problem. I will post back in a week or so with the final result.

thanks.

[marc780]

YW Zro. If you looked at the codes AFTER you cleaned the tbi, its a safe bet some of them were caused by the carb cleaner. So i'd reset everything by removing the battery clamp for a couple minutes and then reclamping; and check the codes after that.