I've noticed hesitation occasionally on a cold start with my GTS recently. It's only low rpm hesitation and is worse when cold. I've cleaned the throttle body and MAF sensor on my 997.1 and found it really helped fix the low end torque and throttle response. In fact, I'd thought I needed to improve my shifting skills at launch, but the better engine response fixed the problem!

My question is what's the procedure to do something similar on the 997.2 - or can you? I know there's a MAF sensor and throttle body, but I've not found any procedure guides online. The air filter replacement only requires removing the top of the housing, so not sure what's next.

Anyone with experience on this?

 

I have cold weather hesitation around 2-2.5 k rpm. Happens about first 40-60 seconds in the morning. Had it at dealer a couple of times. They kept it there over night and were able to reproduce the problem. They contact PNA and conclusion was, normal variant.
So if you clean it and it works let me know how to do it, would be happy if I can get rid of this.
BTW I replaced the air filter. No change.

 

first 40-60 seconds ??? this would be normal IMO.
Subscribed.

 

This is what they said. Normal variant. But in the days of modern DFI etc etc.
I thought this would not happen.
Reminds me of the choke I had on my 1972 MGB convertible

 

well I believe that it s the same principal as the MG, The ECU is still in the COLD engine map.

I have taken my airbox out up to the intake area and have cleaned that out by hand.It was pretty black in there with only 10K miles. Interested to see what else can be done also.

 

My problem isn't cold weather related, but occasional cold start hesitation, and not normal, it's pronounced. I'm going to clean the throttle body and MAF, but before digging in, wondered if anyone has pulled the TB on the gen 2. I've done this on my gen 1, but the air box is different, as is the TB. So before I start yanking and disassembling, was looking for a bit of guidance. Do you have to remove the top of the box exposing the filters before getting to the bottom of the box, or can you remove it assembled? Any torque requirements for the TB when reinstalling?

 

I did mine but don t remember it all. I think someone had a DIY or post about it. Yes, remove the top and filter first. There is a plug/clip and hose on right side also. Just remove and remember to re install. No torque reguirments really. Just don t over tighten and break anything. It was pretty straight forward.

 

hey, I just remembered there is also a key function to re set the throttle startup (cold )
that might help. again you d have to do a search for details. If I see it I ll post it. That might be more help than the throttlebody issue.... what kind of miles do you have on it?

 

https://www.6speedonline.com/forums/...tle-reset.html

read thru this....

 

I had some huge throttle body issues on my 2010 C4S and I cleaned and ended up having to replace it recently. There was a strange amount of play in it and it was idle hunting and lumpy all over the place. Anyway I had to remove the entire air box because the main hose going to it is so tight. Remove the 4 bolts and give it a good wipe down. Be gentle with the flap so you don't damage the servo. It was a bit of a pain to get the air hose clamped back on the TB. Easy to do just take your time.

 

I attended a Tech session at our local dealer a few weeks ago and posted a question to their lead tech.

• "Is it possible to remove the TB to clean it properly?"
• Response: "Yes, very easy to do...there is a small rubber gasket between TB and intake manifold that you SHOULD replace during re-assembly...but there are no coolant hoses or rad fluids that will leak out (as on some other makes)."

I have already cleaned my TB the old fashioned way...holding it open with my fingers and cleaning with TB cleaner, toothbrush and lint free cloths. MAKE SURE the ign key is OFF. However, it would be a lot easier to re and re the TB to clean properly. Unfortunately, I did not ask for the torque spec to remount it to the intake manifold. My 997.2 C2S has 24000 kms on it now and I've cleaned it twice (once each spring for the past 2 years as part of my pre-season maintenance). The first time was the most dirty at 14000 kms, and each time since it hasn't been very dirty at all...easy to clean. The instructions for removing the airbox / filters, etc are posted on here...just do a search.

 

Thanks for the comments everyone.

I was able to clean both the MAF sensor and throttle body. I've heard alternative opinions on cleaning the MAF, but I've done it on my gen 1, and it's pretty easy to do, so no harm (assuming you're careful and treat it like sensitive electronics).

The air box seems like a bit tighter fit than the gen 1, and I ended up pulling the top off to access the filters first, though I don't think it's necessary. Key tricks are to loosen the vacuum hose clip on the right (I just pushed the gray clip loose, but left the hoses connected and the air box dangling). To disconnect the MAF sensor, you slip a screwdriver into the back side and release the clip (if it doesn't release easily, you don't have the clip slipped loose).

There are three stalks that the air box fits into, you'll see the blue washer. I'm always losing the rubber grommets on the two lower ones and have to fish them out of the engine. Keep track of those.

My TB was quite dirty with black soot - this at about 18K miles. My gen 1 would show more of a brown, shellac-like contaminate. This was more a black soot...so not sure the implications, but might be differences with the engine.

You have to drive a bit to reset the ECU, so once done, I've noticed an improvement in the low end torque. It's still not as "sublime" as I'd like, so I'm going to attempt the throttle reset idea.