bstudey01

Got my TB upgraded the other day and am having the Idle air control code and idle air control rmp too high codes. I checked all of the vacuum hoses and they all look good. Sprayed brake cleaner at the tb/sc plenum connection no leaks there. My TPS at idle is running .4-.8% and I know this is one reason the code is tripping. The TB is an 82 mm MB part but it was used and has the TB shaft grind on it. For guys that have had this issue, what's the fix? Likely bad TB? I've been reading many threads on this and that appears to be likely. Also noticed during driving the AFR's were stuck at 21:1 under normal driving and fuel trim was at 25%. It didn't change at all with stepping on the gas. Forgot to see what TPS% was during this moment but car was definitely running like crap. Pulled over turned the car off and restart and it was back to normal. At other times it will idle like crap or idle very high, 1800rpm's. Let me know if anybody has some insight on this one

Denroll

It happens too often for it to be a faulty TB, imo. I found a leak by spraying brake cleaner down between the TB and drivers side surge tank. Haven't fixed it yet. I have done the TB reset and a star reset without fixing it. I have noticed that my TPS is really low and I have yet to bump that up with star. My car will drive just fine most of the time and when cruising around with very little throttle, I will get a hiccup and then it runs weird with the lumpy idle. The on/off throttle transition is also really strange after it does this. If I restart the car, it runs fine. Also, my short-term fuel trim goes from normal values to pegging out at 25% when this happens. Restarting the car at a red light brings it all back to normal.

I want to bump the idle up, but need some detailed instructions in star. Anyone have those?

bstudey01

That sounds almost identical to what my car does too. The strange thing is that the same phenomenon would happen before the TB switch. It was much less obvious though and didn't happen ofter either. It never caused a code to be thrown either. Always seemed to happened from a light throttle application after coming to a stop. The idle would get a bit choppy and it would buck slightly. Didn't ever happen when the car was stock. Actually noticed it first after the header/injectors/fuel rail install. Maybe there is a vacuum leak that was never found and it is getting worse now? Maybe from disconnect/connect on of the vacuum lines the connection is getting worse. Sorry about the longer post just thinking out loud. I'm gonna go check all connections again

Shifter

Was the tb plate removed when the shaft was grinded?

Shifter

ME> adaptations> correction programming> idle speed in gear or park neutral

skratch77

I just got a sds setup and messing around in sim mode,when it asked for national version do we use usa preconfigured fault codes? and where do you go after that?

bstudey01

I'm not sure, I bought it that way. I have another TB that I'm gonna try next tuesday and see if it's the problem.

ricecooker713

Possible air leak from an injector seal? It can very much cause this

shardul

iTrader: (1)

Have you tried to recalibrate the TB vis SDS?

shardul

iTrader: (1)

Pre configured fault codes

bstudey01

Yes, Speedriven hooked it up to star after installing. The leak at injector seal does sound possible and will definately have them check it out. Like a said I had a similar issue prior to TB install but never tripped a code and it was much less prevelant

pearlpower

Just a thought, a commonly missed leak is the metal line that runs into the back of the blower between the drivers surge tank and blower. It is a slip fit and will cause those issues. Look down with a light.

Also try another TB calibration.

Unplug throttle body
Move Key in second position -wait 10 seconds
Move key to off, do not remove
Plug throttle body to harness
Move key to second position for 2 min-you will hear tb move around as it calibrates

skratch77

Tb calibration won't do much if there is a leak.the car will allow from 2.7 tips at idle down to 1.2 before it trips a code,if you are seeing 0.4-.08 that is the car closing the tb 100% to keep it from revving to high.

You have a small leak or faulty tb.I'm betting its a small leak bro and don't worry it will pay off when she is up and running.some people say to adjust rpms in star but its like a forum secret and to this day I have not seen one single thread about fixing this issue with star and a how to.I tried 82mm TBS back in the day and had the same problems and ended up getting a 78mm amg tb to work without throwing codes and I just picked up an 82 mb tb so I'm sure I'll run into this also.

berti_00

we shall see when mine gets installed sometimes Monday or so..

skratch77

Just finished my 82mm swap from a 78 so far so good! Didn't even need to use sds

bstudey01

Did you already have the plenum modified?

skratch77

I have an 80mm plenum that I had bored to 82 before I put it on.I drilled the holes a little bigger on the tb and got 3 to line up and the tb sits flush.

Getting 1.6-2.0 tps in drive so i should be good to go.I have a 82mm gasket coming to throw on there also but might not need it.

berti_00

^^did you not remove the snout at all

skratch77

Didn't have to as I did it a while ago with the 78/80 mm tb I had on it.

berti_00

but aren't you going to have a 2mm bore difference from the 80 to the 82mm??

skratch77

My inlet is bored and polished from like 3 years ago.I had an 82mm on there a few times but never a true Mercedes one.

lowprofile

The low TPS reading is either a leak, or the throttle blade was removed while being ported and then not seated correctly when re-installed.
Bumping up the idle is not the solution here.
Being the you were having an issue after the inj were installed, I would look at the inj o-rings as well as the surge tank gaskets, and even the hoses connecting the surge tanks to the i/c.

Just for reference, when I installed the 82 I was getting a TPS reading of 2.4% fully warmed up idling in drive.
https://mbworld.org/forums/w211-amg/...b-install.html

berti_00

ohhhhh gotch yaa your gona love it now

bstudey01

I just looked at some older logs prior to the 82 being installed. Seeing TPS back then of 2-3% at idle. So something has definately changed since the 82mm install. I think the injector o rings is a very good guess to the previous issue. I recall Marcin looking at the individual cylinder diagnostics in star and seeing a slight miss in one of them, not enough to throw a code though. I will have him check those again Tuesday, swap TB with another I have, and try to find a leak in any of the other obvious locations. Really wanted to take her to the strip tomorrow but I'm thinking that would not be a good idea right now.

Worth the wait

I'm a little confused.
It seems you paid speedriven to install and calibrate the tb.
Did you adjust the tune?
Have you asked the installer about this?

Good luck , I hope it resolved easy and cheap!