GT50GO

I've been running a Brenspeed tune since September 2013 with zero issues but since it's gotten 90+ here in Texas when running the AC my idle sometimes drops pretty low (and so far stalled once) when I'm decelerate in stop and go situations. I talked to Brenspeed and they said first thing to do is clean the TB. I don't see any harm in following there suggestion to see if it corrects the problem.
I have no issue physically removing the TB if necessary. I'm old school and have never fooled with a electronic controlled throttle. Is it as simple as just unplugging all the electrical connections, etc... then re-installing? Or is there calibrations that would need done when I put it back on.

Thanks

moosestang

Just unplug the connectors, some might have a pull tab, then push in to disconnect. Remove throttle body and spray it out with TB cleaner or carb cleaner. I use brake kleen cause i'm a rebel. Use a blue towel or what have you to wipe the black stuff out. use your finger to open the butterfly valve and clean all around where it seals. There is no recalibration procedure that i know of.

Don't over tighten it when reinstalling.

It only takes a tiny bit of build up to cause idle problems. My wifes Chrysler had an unstable idle before i cleaned her TB.

GT50GO

Thanks for the input I appreciate it.
I'll be using CRC throttle body cleaner and yes I know all about over tightening bolts from working on previous vehicles! Yes Brenspeed says when ever anyone describes this issue they have them clean the TB first and the majority of the time it fixes the problem.
Since I'm going to be out of town for work all this upcoming week and have to be at the airport early Monday I may wait until next weekend to do this since I'll be in town that week just in case something goes wrong.

vixr

Im a bit confused...what could be the cause of the crud buildup on the butterfly? I pulled the TB off my stock intake at 10K miles to install on the boss intake and there was only a slight film of yellowish sticky stuff. I had some gas on the rag I used to wrap the fuel line, during the stock intake removal, to wipe the stuff right off.

GT50GO

The below is the response from Brenspeed I got. All of it makes perfect since, now do I believe it will fix my issue, well I'm not 100% on that but it will be the first step. If I still have the issue after cleaning then I'll go from there with them.

The reason that we look at the throttle body for idle issues is that when cars come into our shop with a similar complaint, cleaning the throttle body is the very first thing we do. That is because with a custom calibration on your car the throttle body is extremely sensitive from the changes we make to the response time when compared to a stock throttle response. What we see in here is any oil film in the TB can cause strange idle issues.
Trouble shooting problems like this over email is difficult at best. We base our answers on what we see in the shop and hear from the customers we speak with. Starting with the TB is the first step. As to why it might be happening now when the temp is hot, might have something to do with the AC compressor running more often and the engine load that puts on the car. This will bring the idle down, your idle will dip, and for some reason the car cannot recover from this dip. Most of the time this is directly related to the TB.
Oil can build up in the intake system and the TB because the crank case pressure is vented from both valve covers into the engine for emissions. This venting can carry oil vapor. Supercharged cars tend to circulate more oil vapor in the system than NA cars, but NA car will carry oil. This is what makes the TB dirty. Oil separators help, but some oil can still pass through.

moosestang

It's oil being sucked in from the pcv valve. It will eventually turn black. of course some dirt still gets through the air filter and sticks to this oil.

GT50GO

Well I got up early today and jumped on doing the TB cleaning before it was to hot (for me at least). As the pictures shows the front was pretty much spotless but the rear side and were the butterflies sit when closed were pretty dirty. Removing the TB and re installing was no issue and I've driving it about 30 miles in 90 degree weather with the A/C running full bore and so far so good, hardly any idle drop on declaration / stop and go traffic. Also it may just be my imagination but it seems to be a little more responsive. Am I 100% convinced the idle drop issue is fixed.... well let's say I'm 95% sure but the true test will be the 33 mile commute home Monday morning in the afternoon heat. Unless I post again then the problem is fixed.

This is with 10 months on the TB (installed August 2013) and about 9000 miles.

Thanks for all the tips and recommendations.