2.5 Rough idle on cold start
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Hello everyone again. I have a slight problem, my idle on cold start is very rough. Basically, whenever I cold start the engine on cold, RPM reaches 1500 only for a second, then goes down to 900-1200. And I can see engine misfiring. It keeps going like that for a minute, or a little less. When engine is warm, everything is perfect. I changed a new ECT sensor, new double platinum Bosch plugs, manifold is all cleaned up. I do hear some kind of Hissing from manifold, but Carb cleaner doesnt do anything weirdly, and trims are weird.
IAT and ECT readings looks good. MAF is also cleaned.
Now some data from scanner @IDLE:
Fuel system 1 and 2 on CL.
MAF 3-7 g/s on idle, 14.56/g @1098RPM, throttle 11.8%
STFT Bank 1: 25%
LTFT Bank 1: 14.1%
STFT Bank 2: 25%
LTFT Bank 2: 16.4%
Fuel pressure: 375kPa
Intake pressure: 76 kPa
RPM: 914
Throttle Position 4.3%
Lambda Bank 1: 1.249
Lambda Bank 2: 1.215
Oxygen sensors look okay for the readings, tried unplugging them to see some change, but nothing. But I think they only start working when they get warm, and my problem only occurs for 30-60 seconds after cold start, so I thought they werent the issue?
After about a minute, trims start looking way better, and giving some gas, they go -4 to +4.
What should I look at next? Maybe the MAF is faulty? Or make for sure there are no vaccuum leaks by getting smoke test on manifold (because carb cleaner did nothing on all the vacuum lines) ?
IAT and ECT readings looks good. MAF is also cleaned.
Now some data from scanner @IDLE:
Fuel system 1 and 2 on CL.
MAF 3-7 g/s on idle, 14.56/g @1098RPM, throttle 11.8%
STFT Bank 1: 25%
LTFT Bank 1: 14.1%
STFT Bank 2: 25%
LTFT Bank 2: 16.4%
Fuel pressure: 375kPa
Intake pressure: 76 kPa
RPM: 914
Throttle Position 4.3%
Lambda Bank 1: 1.249
Lambda Bank 2: 1.215
Oxygen sensors look okay for the readings, tried unplugging them to see some change, but nothing. But I think they only start working when they get warm, and my problem only occurs for 30-60 seconds after cold start, so I thought they werent the issue?
After about a minute, trims start looking way better, and giving some gas, they go -4 to +4.
What should I look at next? Maybe the MAF is faulty? Or make for sure there are no vaccuum leaks by getting smoke test on manifold (because carb cleaner did nothing on all the vacuum lines) ?
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EnjoyEverySandwich
XK8 / XKR ( X100 )
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03-13-2021 10:34 AM
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