Having high RPMs when engine is cold? No, it is NOT normal! (SOLVED)
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Having high RPMs when engine is cold? No, it is NOT normal! (SOLVED)
So, ever since I bought my used 1990 LS400, I kept thinking that very high RPMs were normal on my car when I first start it in the morning, especially since everyone is complaining about that same issue.
However, since I cleaned my IACV, when I start the car early in the morning, even when it is very cold outside, the RPMs are only a little higher, but not terribly high. They used to be probably in the neighborhood of 3000rpm (don't know exactly since my cluster is not working), now they are more like 1500 rpm at the most. So, big improvement there too. The car used to shake a lot also when it was cold, and although that has a lot to do with engine mounts, now the engine is much quieter and relaxed even when cold.
Next thing I want to see is if I am having any more improvement with MPG - at least I am spending less gas every time I start the car cold.
However, since I cleaned my IACV, when I start the car early in the morning, even when it is very cold outside, the RPMs are only a little higher, but not terribly high. They used to be probably in the neighborhood of 3000rpm (don't know exactly since my cluster is not working), now they are more like 1500 rpm at the most. So, big improvement there too. The car used to shake a lot also when it was cold, and although that has a lot to do with engine mounts, now the engine is much quieter and relaxed even when cold.
Next thing I want to see is if I am having any more improvement with MPG - at least I am spending less gas every time I start the car cold.
Last edited by peterls; Apr 15, 2014 at 04:29 PM.
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From: Redmond wa
So, ever since I bought my used 1990 LS400, I kept thinking that very high RPMs were normal on my car when I first start it in the morning, especially since everyone is complaining about that same issue.
However, since I cleaned my IACV, when I start the car early in the morning, even when it is very cold outside, the RPMs are only a little higher, but not terribly high. They used to be probably in the neighborhood of 3000rpm (don't know exactly since my cluster is not working), now they are more like 1500 rpm at the most. So, big improvement there too. The car used to shake a lot also when it was cold, and although that has a lot to do with engine mounts, now the engine is much quieter and relaxed even when cold.
Next thing I want to see is if I am having any more improvement with MPG - at least I am spending less gas every time I start the car cold.
However, since I cleaned my IACV, when I start the car early in the morning, even when it is very cold outside, the RPMs are only a little higher, but not terribly high. They used to be probably in the neighborhood of 3000rpm (don't know exactly since my cluster is not working), now they are more like 1500 rpm at the most. So, big improvement there too. The car used to shake a lot also when it was cold, and although that has a lot to do with engine mounts, now the engine is much quieter and relaxed even when cold.
Next thing I want to see is if I am having any more improvement with MPG - at least I am spending less gas every time I start the car cold.
Transmission jerk at 1400 RPM was a bit harsh for my taste.
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Instructor
Joined: Feb 2013
Posts: 817
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From: ca
If memory serves me, there should be four small phillips screws on the back, just unscrew them and it will all come off. The middle plunger/valve thing is a screw type so you may have to turn it a few times to come out... and then dip it in b12 chemtool it should clean it up no problem.
Then clean the interior of the housing, there should be some weird looking patterns on sides - those are some type of electromagnets, so they should be perfectly clean (but don't strip the metallic looking finish on that!!!), and watch for the little round flex plate on the bottom, it can easily fall out and get lost...
hope that helps. There is also a write up somewhere, I think on planet soarer or some place like that. Just do a search on google.
Then clean the interior of the housing, there should be some weird looking patterns on sides - those are some type of electromagnets, so they should be perfectly clean (but don't strip the metallic looking finish on that!!!), and watch for the little round flex plate on the bottom, it can easily fall out and get lost...
hope that helps. There is also a write up somewhere, I think on planet soarer or some place like that. Just do a search on google.
Thread Starter
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Joined: Feb 2013
Posts: 817
Likes: 70
From: ca
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