5OF2k
Well-known member
Good morning boys and girls!
I call upon the great wealth of knowledge here on GVR4.org, yet again:
Car:
'91 GVR4
built head
BC 272 cams
BC valvetrain
2gp/1gbr
SMIM
evo 560's
AEM EMS v1
converted to Speed Density with GM 5.1 bar MAP/etc
FMIC/etc
BRAND NEW FIAV
BRAND NEW FIAV bypass plate
Car idles normal for a couple of days, as it should right at or between 850-900 as set by the AEM, but then it decideds it doesnt like it there, and will idle steadily above 1500. It typically will "idle" between 1500-2000, sometimes higher.
Now, as I stated above, the car is on AEM EMS V1, and the tune is clean. I have a good read on the plugs, goos 02 voltage throughout under cruise, WOT, and closed throttle as expected. Both logs and plugs indicate it's not a tune issue(in my opinion).
I've recently replaced the FIAV due to a wandering/hunting idle, and it fixed it for a couple of days, then it came right back and started doing the really high idle (as mentioned above). So, I bit the $31 bullet and ordered the JMF blockoff plate, threw it on quick, and it idled fantastically for a few days, dead on, better than it has since I got the car in the first place. Now, all of a sudden yesterday, the extra-high idle is back, and reaaaalllly irritating the (BLEEP) out of me!
The car has no boost or vacuum leaks, as that was the first things I checked for, with the exception of a very minimal leak at the throttle body shaft seals (when I say minimal, I mean doesnt even register on the guage. I throw 26 psi at the system, and it'll hold for over 10 minutes, easily), brand new FIAV and blockoff plate. Also, my VIS screw is allll the way in, as in tight at the bottom of it's hole in the throttle body. So, in theory, it shouldnt even be running, let alone idling damn near 2k rpm, right?
The only thing I can think of, and what I think I'm going to try this afternoon once I get off work, is the Idle sensor switch. I just figured i'd post up here and make sure I'm not overlooking something completely obvious in my frustrations....?
Any insight, help, or ideas you can provide would be greatly appreciated. Im extremely picky in regards to my vehicles, and this idle issure is getting old, EXTREMELY quickly!
Thanks in advance, have a good one!
-Jake
I call upon the great wealth of knowledge here on GVR4.org, yet again:
Car:
'91 GVR4
built head
BC 272 cams
BC valvetrain
2gp/1gbr
SMIM
evo 560's
AEM EMS v1
converted to Speed Density with GM 5.1 bar MAP/etc
FMIC/etc
BRAND NEW FIAV
BRAND NEW FIAV bypass plate
Car idles normal for a couple of days, as it should right at or between 850-900 as set by the AEM, but then it decideds it doesnt like it there, and will idle steadily above 1500. It typically will "idle" between 1500-2000, sometimes higher.
Now, as I stated above, the car is on AEM EMS V1, and the tune is clean. I have a good read on the plugs, goos 02 voltage throughout under cruise, WOT, and closed throttle as expected. Both logs and plugs indicate it's not a tune issue(in my opinion).
I've recently replaced the FIAV due to a wandering/hunting idle, and it fixed it for a couple of days, then it came right back and started doing the really high idle (as mentioned above). So, I bit the $31 bullet and ordered the JMF blockoff plate, threw it on quick, and it idled fantastically for a few days, dead on, better than it has since I got the car in the first place. Now, all of a sudden yesterday, the extra-high idle is back, and reaaaalllly irritating the (BLEEP) out of me!
The car has no boost or vacuum leaks, as that was the first things I checked for, with the exception of a very minimal leak at the throttle body shaft seals (when I say minimal, I mean doesnt even register on the guage. I throw 26 psi at the system, and it'll hold for over 10 minutes, easily), brand new FIAV and blockoff plate. Also, my VIS screw is allll the way in, as in tight at the bottom of it's hole in the throttle body. So, in theory, it shouldnt even be running, let alone idling damn near 2k rpm, right?
The only thing I can think of, and what I think I'm going to try this afternoon once I get off work, is the Idle sensor switch. I just figured i'd post up here and make sure I'm not overlooking something completely obvious in my frustrations....?
Any insight, help, or ideas you can provide would be greatly appreciated. Im extremely picky in regards to my vehicles, and this idle issure is getting old, EXTREMELY quickly!
Thanks in advance, have a good one!
-Jake
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