2005 GX470 with 108k miles, original owner, new problem. The idle RPM oscillates before engine comes up to normal operating temp. If it's in neutral it drops off to under 500 and zooms up to 1000. If stopped in drive, at traffic light say, the transmission limits the RPM variation but there's a distinct 'bumping' as engine changes speed. Everything back to normal when the engine reaches normal op temperature. No engine check or other warning lights or OBD2 fault code. There *was* a P1445 code (secondary air injection system switching valve No. 2 bank 2 stuck closed) showing after the engine check light and VSC off warning lights came on a few months ago. But the lights later went back off and fault code stopped showing up. I wondering though if it could be related somehow? (secondary air injection system operates when engine is cold, this new thing is also happening when engine is cold). Anyway, I'd appreciate any ideas what could be causing the unstable idle RPM when cold.
Unstable Idle Before Engine Warms Up, 2005 GX470 (1 Viewer)
- Thread starter Corry El
- Start date
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Initial thoughts would be a dirty throttle blade (remove the intake and clean it with carb cleaner), dirty or bad mass air flow sensor (remove and clean with MAF cleaner, or just replace with a new OEM-grade Hitachi unit), or a vacuum leak (requires watching fuel trims via an OBDII app and using a un-lit propane torch applies to various vacuum hoses/etc to see if the fuel trims spike negative).
I am not sure if the SAIS could also cause that issue, but IMO, that system is best deleted anyway.
I am not sure if the SAIS could also cause that issue, but IMO, that system is best deleted anyway.
- Thread starter
- #3
Thanks, that's the kind of feedback I was looking for.
agree with this. Hewitt makes a good, complete kit for eliminating the SAIS system.
