High rev on startup for a minute.

[juttin3]

So this has been going on for a while and i couldnt really find anything online.. I know its normal for it to rev a little high on cold starts but my car still does this even when its 90degree. It usually lasts for at least a minute or sometimes more. If i try driving with it like this it doesnt have much power. There are no codes. I just replaced thermostat as that was throwing a map code. What sensors affect how long and when car revs higher on start up.

Second question is vacuum with car parked is at 20 but when i turn a/c on it goes to 15 is this normal?

Thanks. Justin

1.8a4 05 amb tip

[QTC]

High revs like 1200 RPM, or 4500 RPM? If its the latter (or anything higher than the normal 1-1200 startup), it could be a sign of the throttle position sensor starting to go.

[jpulll]

When i turn the AC on, my vacuum goes from 20-22 to 16-18.

[CyberPMG]

The A/C will cause the engine to run at slightly higher RPMs and cause the vacuum to be be higher. This is normal in hotter weather. You'll also notice the heat soak more making our cars feel more sluggish. Welcome to summer.

[blitz2190]

So this has been going on for a while and i couldnt really find anything online.. I know its normal for it to rev a little high on cold starts but my car still does this even when its 90degree. It usually lasts for at least a minute or sometimes more. If i try driving with it like this it doesnt have much power. There are no codes. I just replaced thermostat as that was throwing a map code. What sensors affect how long and when car revs higher on start up.

Second question is vacuum with car parked is at 20 but when i turn a/c on it goes to 15 is this normal?

Thanks. Justin

1.8a4 05 amb tip

if its the first start in more than around 5-6 hours even if its 100 out it will still rev to about 1200 for a minute to warm the cats up, its an emissions thing. The only time it doesn't do this is when it gets to cold because at a point it becomes inefficient.

[Luxus Panzer]

slightly higher RPMs and cause the vacuum to be be higher..

You mean LESS Vac due to higher RPMs ;)

[CyberPMG]

You mean LESS Vac due to higher RPMs ;)

Yes, lower vacuum numbers. Coffee didn't fully set in when typing.

[juttin3]

Yes it's around 1200 rpm for around a minute. Also the secondary air pump is loud at this time so maybe this is why I notice it more. I have a 034 cat with a Black Forest spacer for 02 sensor. Could that change the warm up time? I don't have any codes for cat or 02.
The throttle body connector was water damaged and had to be spliced out and throttle body was also replaced.

[blitz2190]

Yes it's around 1200 rpm for around a minute. Also the secondary air pump is loud at this time so maybe this is why I notice it more. I have a 034 cat with a Black Forest spacer for 02 sensor. Could that change the warm up time? I don't have any codes for cat or 02.
The throttle body connector was water damaged and had to be spliced out and throttle body was also replaced.

already explained it, it always takes about a miunte

if its the first start in more than around 5-6 hours even if its 100 out it will still rev to about 1200 for a minute to warm the cats up, its an emissions thing. The only time it doesn't do this is when it gets to cold because at a point it becomes inefficient.

[WB650]

Unless I'm in a rush, I never drive before my RPMs drop. IDK why