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help with rough idle low throttle response at startup
I wonder if anyone has experienced this and has suggestions as to how to fix.
I purchased my first 911 back in 2018 a 1986 3.2 carrera with 168,00 miles and slowly have been working on it to get her up to proper running condition. Right now I'm diagnosing a cold start idle issue which has been occurring since I purchased. Im finally getting around digging deeper. When I start up first thing it will do is sputter and the RPM will surge and then rough idle at lower RPM intermittently. If I play with the throttle it will smooth out and then start to find its proper idle. But when engaging the transmission to move the car the throttle response bogs down and the power is not there. I need to get the engine warmed up for several minutes before it begins to smooth out and get more power. I have not driven other older 911 for any extended time so not sure how a correctly sorted one will run. Even when warmed up I wish there was more snap to the throttle and direct engagement with the engine. Some of the things Iv done up till now are clean out the idle stabilizer replace the plugs, wires, rotor/cap O2 sensor, crak shaft position sensor, speed sensor, fuel filter, several injectors that were clogged and leaking did a valve lash and oil change all things that were needed. I'm not sure why the idle issue has not been remedied after that. If anyone has some ideas as to where to look next other than taking it to a $$$hop I would much appreciate some input. I added video of the cold start. Rough at initial start up then smooths out then when cracking accelerator it hesitates and coughs a bit. https://youtu.be/soh8yqu4l34 Thanks ![]() Last edited by moush993; 02-08-2021 at 02:52 PM.. Reason: added videos |
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make a video of your problem..
Ivan
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1985 911 with original 501 761 miles...807 506 km "The difference between genius and stupidity is that, genius has its limits". Albert Einstein. |
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video added
I posted a link of cold start
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Beautiful car!
Mine was doing the same thing but worse . Sounded Like it had radical cams like a hot rod . I found bad intake gaskets, several . Could have been a vacuume leak . Not sure if that was the cause yet , Still putting The car back together. |
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Join Date: Dec 1999
Location: Novato, CA
Posts: 4,740
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After reviewing your video I could tell your base idle is set way too low.
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clean Air idle control valve
simple and the first thing to check
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PCA, POC & SCCA long time Member |
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Join Date: May 2008
Location: Grapevine, TX
Posts: 1,105
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My guess aligns with sparkys. Buy, build or borrow a smoke machine and test for intake leaks.
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thanks for the suggestions Im suspecting intake gaskets might be the issue seeing Iv done quite a few of the other things that could be the cause. It does sound like a hot rod mild cam set up.
I did clean the idle control with carb cleaner. looks spotless. |
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