GS430Blue

When I accelerate at a low speed the car up shifts to soon, but when I accelerate with some gas it is fine. So I pulled codes and there was no alert to transmission. I had CO 226 236 and 246 but don't believe this to be associated...Right? So I question if it is the Transmission Control Module but car doesn't jerk, go in safe mode, fine gas mileage, or down shift to soon. Also question the Shift Solenoid but again symptoms really match. I believe I have ruled out Throttle Control but I do have a rough idle and figure it's the Idle Air Control Valve. I do have PO 440 441 and 446, but pretty certain it's the gas cap. Again...only happens if I gingerly accelerate....Any Thoughts?

DMPesso

that’s how the car is designed. Put it in ECT PWR mode and it will shift at a higher rpm and stay in a lower gear.

Rough idle, if you have it only when the car is in drive and you come to a stop, that’s motor mounts most of the time. If it’s when your idling, parked or driving that’s definitely another issue.

Drive the car aggressively and it will learn to shift at a higher RPM. It adapts to the way you drive and will always have a preference to be in the highest gear possible to save gas. If you drive at a low rpm it will be in 5th gear by the time you hit 30mph. Resetting the ecu also helps.

GS430Blue

I'll reset ECU and see what happens.
I've watched some vids on cleaning Idle Air Control Valve, but most other car valves I have seen are not like that of a GS... I haven't taken a look yet, but from pics of GS Valve, it appears the valve cannot open for cleaning and needs to be replaced. Thought??
Thanks...

firelizard

iTrader: (1)

The GS430 has an electronic throttle, it does not have an idle air control valve. Do you have a inconsistent idle, or a consistent idle but a lot of vibration? Like DMPesso said, motor mounts in need of replacement are known to cause a lumpy-feeling idle.

GS430Blue

Thanks for your input and advice...
As an update....I changed my plugs and the shifting issue is resolved. As far as the idle, in neutral it's perfect but while in gear it's low and a little rough. I did add BG44K to a full tank of gas and experienced a marked increase in idling within 2 days - super impressed with this product - If 2nd Gen 430 doesn't have an Idle Air Control Valve, I suppose start looking at Solenoids or Sensors....???? It is not a Motor Mount issue. Suggestions?