02 Tacoma 2.7 normal idle?

Hey guys this is my first post.

I recently bought an 02 Tacoma xtracab 4x4 with 85k. Did all the fluid changes except for coolant and replaced plugs. Re-greased driveshaft u-joints and slip yoke. Also had the steering rack and engine mounts replaced because they were shot.

From the get go I had a rough idle issue and it seemed like it was idling low (550-600). Cleaned maf and IAC valve and no more rough idle.

However, now truck idles around 750-850 and it seems to me like it is a bit high. Truck runs really strong and everything now.

Am I being too picky about the idle rpms or should it be lower? Haven't driven it too much after the IAC was cleaned so maybe the ecu is just adjusting?

Any help is appreciated. Thanks!

 

My 3rz in my 96 does the same thing idles around 750

 

750-800 for me

 

My 2000 2.7 is around 1000-1200

 

Cold?!? Mine does it when it's cold. But, after that it goes down to 750.

 

Well the only time i look at it is when I start it so that may be the case

 

Yeah I guess just reading other posts that their trucks run around 600 that I think mine is too high. But before I cleaned the IAC mine was running around 650 and it was a rough idle

 

its not really anything you can do because the ECM adjust the idle for you but if the idle is a little high its a sign of an air leak somewhere so check you vacuum hoses for cracks and check gaskets for leaks but chances are it just needs time to reset itself after being cleaned.

usually 3 or 4 driving cycles of at least 5 minutes and it should be normal again unless there is an air leak somewhere but if the a/c is on it will idle at around 700-750 to compensate

 

My '97 used to idle around 1200, I fought with that forever but now I think I got the kinks worked out and she's idling around 700-750 once warmed up

 

So when I brought my truck in to my mechanic I think they had checked for vacuum leaks and said there were none but since it is a small idle difference it may be a leak that went unnoticed?

Is this higher idle something that may do harm to the engine or is it just compensation for the vacuum leak if that is indeed the problem?

Driving around recently its idling from just over 750 to 850 but the idle doesn't fluctuate up and down stopped. Just a bit down initially and then is steady and smooth

 

no, it wont hurt anything

 

Hey guys so thanks for your input. Hopped in the truck today and the idle magically went down to where it idles around 650 when warm and in gear. Unfortunately the shake has come back but not nearly as bad as before.

Is it normal for these trucks to shake a bit at idle? Not teeth rattling but does make the dash rattle a bit.

 

Also seems now that there is less power with the truck now that the idle has dropped. Gunna do a compression test tomorrow to see if its engine related (ie. valve clearance needs to be adjusted) hoping for the best as there only is 87k on the clock

 

4 cylinders just idle more roughly than a 6, which is rougher than an 8, which is rougher than a 10,, which is rougher than a 12, etc...

It's the difference between a power pulse every 180 degrees of crankshaft rotation vs one every 120 degrees of rotation for a 6.

 

So you think its unnecessary for me to do the test? When it idled higher it was super smooth and seemed to have more get up and go.

I guess I'm concluding that the cleaning of the iacv leading to a temporary high idle wouldn't hide the effects of lower compression in the cylinders?

It just seems like the truck lost power but now that the idle has gone down a bit when I shift into drive I cannot hear a thunk anymore less stress on the drive train I guess

 

Shake is all the way back to what it was before I cleaned iacv. Switched the plugs to OEM densos today just to see if the ngks I put in were causing the rough idle. Well no difference. I'm at a loss now and there are no codes being thrown whatsoever.

Before the IAC valve was cleaned I had a p0100 and p0110 codes thrown and cleaned the maf and haven't gotten any of them to pop back up. Anyone think it could be a bad maf/iat sensor?

 

So brought it back to my mechanic for no charge and they ran a bunch of tests, checked for vacuum leaks and other stuff all day and all they can conclude is that the IAC valve is prob bad and should be replaced. Anyone think this should be the direction I should take?

Maybe try getting a used one before I go and fork over 200+ for a stupid little valve?

 

Dude.. A lot of people have idle vibes with 2.7s it's pretty common. I myself have it and have been searching for the cure for quite some time now. I think my RPMs are around the 650ish mark but I'll let you know next time I drive it. I literally have a reman'd 3rz with like 10k and I still have the vibes.
I came across a post that I found very interesting recently. They claimed that our exhaust pipes don't have enough mounts going to the frame and when the RPMs drop below 700 during idle the engine has a hard time pushing the exhaust out or something and it makes the exhaust system shake which makes your cab slightly shake. He explained it a bit better than I, but basically what I'm trying to say is have someone drop your truck in drive and take a look at your exhaust pipe. I bet its shakin like crazy. I'm pretty sure that's the cause in my truck because I've seen my exhaust shaking like crazy. I haven't gotten around to trying the fix yet though..

However if you noticed a serious difference in power and have access to compression testing tools by all means test it out. Mine failed compression last year which is why I went with a reman.

Edit: I've also replaced more things than I care to admit chasing this vibe..

 

Thanks for your help presto. Actually earlier this week I did get under when someone had it in drive and the exhaust shook a bit. But the majority of the shaking is coming from the tb/IAC area. I know how my truck ran after cleaning the IAC and it was really smooth so I don't feel like its out of the question that my truck should run that way

 

It always ran smooth for a while after I did something similar. I'd always think I fixed it then a day or 2 later same thing it always comes back. Not trying to discourage you or anything.