Greetings everyone, can I ask for a little opinion. Why when i turn on ignition key ON but my throttlebody does not sound the stepper motor rotating? When i continue to start, the CEL is on and the car cannot be more than 2k rpm. When the engine running for about 30 minutes. I switched off the engine and restart CEL disappears and the symptoms continue to disappear. This will be happen once in a day only. TB and ECU is newly replaced. The wiring is new. Spark plug also i check got thre current. New fuel filter as well. Can anyone help me out on this issue. I got the code of P0121. But last time i send out to proton they change new TB. But can this TB be defect within 1 year?
P0121 is TPS related and since it's a VDO it's probably the TB.
But since your TB is new it's likely something else. Btw what TB did you change to? Brand new? China OEM? Half cut? The VDO TB is one bitchass sensitive piece of crap that gets out of alignment if you accidentally knock it when you dismantle the thing for cleaning.
Anyway if you're confident of the TB, I'd suggest looking at your wiring. If the problem isn't there when the engine is hot it more than likely is a contact problem somewhere. Either in the TB/TPS or the connector on the TB side (I can't recall if there is one). It there is some wiring plugged into the TB side, try this when the engine is warm : Try to shake or wobble the wiring around the TB and see if the car reacts to that. If the car suddenly starts to sputter then you found your culprit.
If nothing happens it's more than likely you got a lemon TB.