2010 911 C4S surging question
04-07-2017, 09:57 AM
#46
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Gentlemen- it's been a pleasure. Tip of the hat to Bruce in Philly and Rod928, and the rest of you guys; this was indeed an education. The reason for this surging, and unstable idle in colder air was--- a very dirty throttle body. The dealer here in Houston actually acknowledged that could be the problem when I told him what our forum recommended. I brought it over, and they volunteered to clean it. I sat w the mechanic, and he pulled off the rubber inlet, and commenced to spray and brush the flapper and interior. It rained dirty fluid for 2 minutes. 53K miles and 6 years loaded it up. With what? Can't be carbon, it's upstream of combustion. This is intake air. Dirt & Soot from the exhaust? I am surprised that Porsche does not recommend spray cleaning the MAF and brushing the TB when the air filters are changed out. That just makes sense. You can bet I will be doing that on an annual basis. Not only did the surging go away (today it's 58F, so it would have been bad), but the take off right after starting was smoother. For a long time it would rock a bit when it first started off. This started long before the surge issue.
In doing all of this research, I came across several performance air filters that replace the existing setup. FABSPEED has a carbon fiber version (about $900) that looked great, and claimed +14HP. Not sure if it's worth $64/hp to add it, but it would make access to the MAF & TB easy to clean, and you don't change those filters, just clean them. Any of you guys ever swap out for a performance AF kit?
In doing all of this research, I came across several performance air filters that replace the existing setup. FABSPEED has a carbon fiber version (about $900) that looked great, and claimed +14HP. Not sure if it's worth $64/hp to add it, but it would make access to the MAF & TB easy to clean, and you don't change those filters, just clean them. Any of you guys ever swap out for a performance AF kit?
Just curious ... after the Dealer cleaned the TB, did he then go through the TB reset procedure?
04-07-2017, 10:26 AM
#48
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JDgamble- It was some kind of basic carburetor cleaning solvent he had in a watering can looking thing. It wasn't an aerosol spray, but something I'm sure he reloads from a solvent drum they buy. He pumped up the can and shot it like a bug exterminator into the TB, then would use the brush to scrub it off. I also have a Chevy truck that is running rough (60K miles), and my plans are to pick up some CRC TB cleaner today and do the same thing there.
04-07-2017, 10:28 AM
#49
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North Shore 911- YES, he did. After he reassembled the AF, he hooked up his PIWIS and said he had to 'reset' the TB position for the car to recognize. I forgot to mention that. I asked him if I had cleaned it at home, how would I accomplish this? His answer was that it would run rough for a bit but the car would reset the TB position itself. The PIWIS just did it immediately.
04-07-2017, 10:55 AM
#50
You can reset it not using the PWIS with a sequence of key on/off and pushing the throttle. When you install the GT3 TB you have to do it too. Its in the IPD instructions.
https://www.6speedonline.com/forums/...tle-reset.html
https://www.6speedonline.com/forums/...tle-reset.html
04-07-2017, 11:18 AM
#51
RL Community Team
Rennlist Member
Rennlist Member
North Shore 911- YES, he did. After he reassembled the AF, he hooked up his PIWIS and said he had to 'reset' the TB position for the car to recognize. I forgot to mention that. I asked him if I had cleaned it at home, how would I accomplish this? His answer was that it would run rough for a bit but the car would reset the TB position itself. The PIWIS just did it immediately.
Peace
Bruce in Philly
04-24-2017, 07:41 AM
#52
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Okay- today was the coldest air we've had since the TB was cleaned (55F). Believe it or not, after driving about 20 miles at steady speed, I felt the surging again. Not as bad as before, but very subtle. I know it was legitimate because when I stopped and watched the idle, it went back to hunting again from 600-900, which is a sure sign. That means that cleaning the TB helped, which also means the problem is related to something else that is fouled or dirty-- Question: What is next in the intake system that could be fouled and is able to be cleaned? Is there another flapper or similar that is possibly the culprit?
04-24-2017, 09:00 AM
#53
Have you looked for vacuum leaks? Check all the clamps and hoses on the air intake to the TB to the plenum to the intake runners. When I changed out my TB and plenum, I found two or three loose ones....There could also be small cracks or tears leaking unmetered air into the system.
04-24-2017, 09:04 AM
#54
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Have you looked for vacuum leaks? Check all the clamps and hoses on the air intake to the TB to the plenum to the intake runners. When I changed out my TB and plenum, I found two or three loose ones....There could also be small cracks or tears leaking unmetered air into the system.
04-24-2017, 02:03 PM
#55
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In my car (2009 c2s) the problem was the Throtle position sensor (the black plastic box attached to the TB). The potentiometer inside gets dirty. You can clean it or just go ahead and buy a new throtle body (what I did)...
04-24-2017, 03:57 PM
#56
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997.2 2010 C4S
Exposed TB- 997.2 engine (2010 C4S)
Is the throttle position sensor easy to remove and clean (like the MAF?). Is that it there to the right(?) of the TB? Not sure what to do there.
04-24-2017, 06:06 PM
#57
Instructor
When car is idle hunting, open the engine lid and listen for a weird metallic flapping. That is what I heard when my throttle body went bad. It was basically flapping around in there because it got play in it. Had to replace it. I had that hunch that it was my problem and I should have done this...
Buy one on Ebay. (check part#)
http://www.ebay.com/itm/PORSCHE-997-...FVrDqK&vxp=mtr
Throw it on there and see if it fixes it. If not sell it back on eBay.
I wish I did this and not just taken to dealer.
Buy one on Ebay. (check part#)
http://www.ebay.com/itm/PORSCHE-997-...FVrDqK&vxp=mtr
Throw it on there and see if it fixes it. If not sell it back on eBay.
I wish I did this and not just taken to dealer.
04-24-2017, 08:46 PM
#58
You say it improved with the throttle body cleaning. You also indicated that you saw how the mechanic cleaned it - leaving it in place and spray and pray. It would be zero cost for you to pull the throttle body off and do a more thorough job.
04-24-2017, 09:57 PM
#59
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