Stumbling when cold??????
05-14-2007, 10:36 AM
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Stumbling when cold?????? When I first start the car and start driving I have a bad stumbling/cutting out problem. Almost sounds little backfires..... loading up? as I accelerate. Once the car is at full temp it completely goes away and runs strong. Any idea what may cause this? I don't know if its a computer problem or something else?????? I have been having this problem for several weeks.......
I changed plugs and it seemed to go away for about a week... Then started doing the same thing.........
Dan
I changed plugs and it seemed to go away for about a week... Then started doing the same thing.........
Dan
05-14-2007, 10:44 AM
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At this point, it's all speculation, but it sounds like it might be open loop tune related. Once it's warmed up, it goes into closed loop and runs fine.
Maybe you changed the tune recently, or when it was colder out? The warmer weather might affect the accuracy of the open loop tune. As I said, it's speculation without more information.
Maybe you changed the tune recently, or when it was colder out? The warmer weather might affect the accuracy of the open loop tune. As I said, it's speculation without more information.
05-14-2007, 10:52 AM
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no change in tune, I did put new o2 sensors in trying to solve the probem but that didn't help. I did ad a fast 90 intake/tb since the last tune but it has ran for a year without the stumbling.
I also opened up the SB blades (adj screw) to get it to idle a little smoother... could this cause a prob?
I also opened up the SB blades (adj screw) to get it to idle a little smoother... could this cause a prob?
05-14-2007, 11:00 AM
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You're an M6 car so changing the intake and TB shouldn't really require a change in the tune although your WOT fuel mixture might be able to use a little tuning.
Well, you're not supposed to adjust idle quality with the adjusting screw unless the it surges at idle (due to the plates being closed too much) or the idle speed is too high (due to the plates being open too much). If you have idle quality issues, you need to change the idle parameters in the PCM programming.
Having said that I can't think of how that would cause the symptoms you describe. However, I would suggest adjusting your throttle plates so that your IAC count is around 30-40 at idle, and make sure your TPS is properly adjusted, just so we can rule this out as a cause.
Well, you're not supposed to adjust idle quality with the adjusting screw unless the it surges at idle (due to the plates being closed too much) or the idle speed is too high (due to the plates being open too much). If you have idle quality issues, you need to change the idle parameters in the PCM programming.
Having said that I can't think of how that would cause the symptoms you describe. However, I would suggest adjusting your throttle plates so that your IAC count is around 30-40 at idle, and make sure your TPS is properly adjusted, just so we can rule this out as a cause.
05-20-2007, 09:31 PM
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Mine's kinda doing the same thing. Of course search is down. 
I am running stock open loop table in my 396 and getting the stumbling and exhaust pop til it goes to closed loop. I was thinking maybe bumping the table by 5% for a higher target AFR. Seems to do ok when air temp is in the 40's, making me think fuel. Did you get yours figured out TAGOES11S?
I am running stock open loop table in my 396 and getting the stumbling and exhaust pop til it goes to closed loop. I was thinking maybe bumping the table by 5% for a higher target AFR. Seems to do ok when air temp is in the 40's, making me think fuel. Did you get yours figured out TAGOES11S?