Why does the idle bottom out when it drops from high RPM?

S-mk3-B · 07-16-2013, 12:48 AM

That ECU could probably be the issue or related in some way, as well as the mods since you said it was "heavily modded". But first things first, are there any error codes that come up? And does this problem happen when you rev in neutral as well?

cre · 07-16-2013, 07:56 PM

If the car has a BOV instead of the factory bypass setup (aka BPV) then that may be the problem by itself. The AEM can be tuned to account for this. This is only a possible issue if you're running the stock KVAFM or a MAF. Speed/density (MAP) setups are generally not susceptible. There's not a lot of help which can be offered if the car is heavily modded unless you begin posting exhaustive details about the build, ECU tune, diagnostic and runtime logs and so on.

07-16-2013, 12:48 AM	#1
S-mk3-B 3" Exhaust Join Date: Mar 2012 Location: San Francisco Posts: 72	That ECU could probably be the issue or related in some way, as well as the mods since you said it was "heavily modded". But first things first, are there any error codes that come up? And does this problem happen when you rev in neutral as well? __________________ 1989 Toyota Supra Turbo w/ Targa Top White Exterior-Blue Interior 3" Blitz Catback Exhaust System BIC Divorced Downpipe, Straight Pipe Megan Track Coilovers Apexi BOV, Turbo Timer, and Intake Lexus Projector Fogs Bride Low Max Replica

07-16-2013, 07:56 PM	#2
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	If the car has a BOV instead of the factory bypass setup (aka BPV) then that may be the problem by itself. The AEM can be tuned to account for this. This is only a possible issue if you're running the stock KVAFM or a MAF. Speed/density (MAP) setups are generally not susceptible. There's not a lot of help which can be offered if the car is heavily modded unless you begin posting exhaustive details about the build, ECU tune, diagnostic and runtime logs and so on. __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

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