CRAZY irregular idle after Cosworth IX Cam install! Why? Does it even make sense?
#1
CRAZY irregular idle after Cosworth IX Cam install! Why? Does it even make sense?
Hey all...
I had a local Evo shop install a set of new Cosworth Cams (both intake and exhaust) in my 9 a couple months ago. When I go to start the car ever since the install (and still to this date), the car idles properly until warm. Once the car is warm and has been driven (sometimes even when not driven) it has the weirdest irregular idle I have ever seen:
It sits at normal idle (approximately 750-850 RPM) for about 10 seconds and then jumps and holds at 1000-1100 RPM for anothe 5 seconds. It keeps alternating back and forth, back and forth, back and forth, etc.
Does this sound normal at all? What could be the cause of this and how can it be fixed?
My tuner did not alter the idle from stock because ECUflash cannot control the IX idle (Did someone figure out how yet?). This occurs when no accessories are on too. It is very strange because the BISS screw has not even been touched from my knowledge...
Let me know what you guys think!
Thank you!
I had a local Evo shop install a set of new Cosworth Cams (both intake and exhaust) in my 9 a couple months ago. When I go to start the car ever since the install (and still to this date), the car idles properly until warm. Once the car is warm and has been driven (sometimes even when not driven) it has the weirdest irregular idle I have ever seen:
It sits at normal idle (approximately 750-850 RPM) for about 10 seconds and then jumps and holds at 1000-1100 RPM for anothe 5 seconds. It keeps alternating back and forth, back and forth, back and forth, etc.
Does this sound normal at all? What could be the cause of this and how can it be fixed?
My tuner did not alter the idle from stock because ECUflash cannot control the IX idle (Did someone figure out how yet?). This occurs when no accessories are on too. It is very strange because the BISS screw has not even been touched from my knowledge...
Let me know what you guys think!
Thank you!
#3
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Thread giving the correct IX idle tables. There is one more table on the last page, but adjustment of it didn't seem to change much at all.
I don't think increasing your idle speed is going to be the answer. I'd look in to your VVT map and see if any changes were made there.
I don't think increasing your idle speed is going to be the answer. I'd look in to your VVT map and see if any changes were made there.
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#10
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My car does the same thing with the cosworths it swings up and down 200-300 rpms. I got a check engine light code was "idle position sensor". I wish it could just stay at 800rpm instead of swinging back to 1100 or so and then back down. When i go back to Al i will ask him about this.
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i just did a cosworth cam install on a customers car just last sunday. it also had a terrible idle problem right from the get go (idle dipped to 500rpm and then up to 1000 and back and forth). the tables in ecuflash had no effect on the idle, so we fiddled with the BISS and it idled better. then i remembered seeing those extra idle tables in a post so i added them and sure enough, it controlled the idle just fine. i moved the BISS back to were it started, and car idled just fine.
https://www.evolutionm.net/forums/sh...=283300&page=5
post number 66 has the link your looking for
https://www.evolutionm.net/forums/sh...=283300&page=5
post number 66 has the link your looking for
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