RPMs eratically dropping
Thanks for the insight. I'm glad to know I'm not the only one with this problem however so we can find a solution to this. I don't believe I have a boost leak as I can boost properly and my car was just recently logged using Evo Scan. I could check the IAC valve again, but what do you suppose I try adjusting with it? Are you saying to mess with the idling screw, because at the moment I hear a hissing sound coming from the screw when I play around with adjusting the idle. Im not too sure if this is normal or not?
Thread revive:
I'm having a weird problem as well:
some months ago started having a problem with the car idling funny... all vacuum lines were changed and still did the same thing.
- Changed IACV for a newer one and still did the same.
- Backed out BISS screw after parking the IACV in evoscan and the car just ran like I had cams...
- Plugs were changed and same issue. Wires and coils were in resistance spec
So I ended up turning the BISS screw right out with the IACV re engaged and slowly screwed it in till it was ok.
But not I just installed a test pipe with an Autometer wideband... and was running fine till i decided to give it full boost one night and the problem returned.
at around 700-900 or so the afr would drop to 12.7 or so... jump to 15.0, cycle again and the car would get erratic idle
- EGR cleaned same issue... everything from previous done and still didin't help.
Replaced the JDM MR valve I had with the stocker and strangely enough adjusting the BISS screw to 1000 or so the idle was fine. But when I turned on the A/C and the IACV adjusted to the preset RPM of 850 or so i believe and it started idling badly again.
Edited it in ecuflash to idle higher and that is fine. Now if I let the car coast in any gear and once it gets to 700-900 range the car starts bucking and the afrs do the same as stated above. Once the RPM goes higher the afrs settle back to 14.7 and no problems at all.
So I can't figure out why ONLY between 700-900 RPM the car idles erraticly with the AFR running rich then going back to 15.0 cycle. When it was set to lower idle and it was acting badly, I lightly touched the gas pedala nd as it held steady nearer to 1000rpm it idled good and the afrs went steady...
weird.
I'm having a weird problem as well:
some months ago started having a problem with the car idling funny... all vacuum lines were changed and still did the same thing.
- Changed IACV for a newer one and still did the same.
- Backed out BISS screw after parking the IACV in evoscan and the car just ran like I had cams...
- Plugs were changed and same issue. Wires and coils were in resistance spec
So I ended up turning the BISS screw right out with the IACV re engaged and slowly screwed it in till it was ok.
But not I just installed a test pipe with an Autometer wideband... and was running fine till i decided to give it full boost one night and the problem returned.
at around 700-900 or so the afr would drop to 12.7 or so... jump to 15.0, cycle again and the car would get erratic idle
- EGR cleaned same issue... everything from previous done and still didin't help.
Replaced the JDM MR valve I had with the stocker and strangely enough adjusting the BISS screw to 1000 or so the idle was fine. But when I turned on the A/C and the IACV adjusted to the preset RPM of 850 or so i believe and it started idling badly again.
Edited it in ecuflash to idle higher and that is fine. Now if I let the car coast in any gear and once it gets to 700-900 range the car starts bucking and the afrs do the same as stated above. Once the RPM goes higher the afrs settle back to 14.7 and no problems at all.
So I can't figure out why ONLY between 700-900 RPM the car idles erraticly with the AFR running rich then going back to 15.0 cycle. When it was set to lower idle and it was acting badly, I lightly touched the gas pedala nd as it held steady nearer to 1000rpm it idled good and the afrs went steady...
weird.
Thread
Thread Starter
Forum
Replies
Last Post
