I switched to the VAFC hack 2 days ago and my car is running pretty good now except for a weird idle problem. The cars idles good but once it has warmed up if you let idle for about 30 seconds it will suddenly bog down to about 4-500 rpm for a second and almost die, then instaltly go back to 7-800 rpm and idle fine for about another 30 seconds then do the same. While driving it runs fine, never bogs or anything. Ive tried resetting the ecu, it still does it though. Its really annoying, has anyone else seen this or have any ideas? TIA!!!

 

mine does that too every now and then

 

How much FUEL are you trimming at 1K RPM?

 

yea, how much fuel are you trimming..? you might be running rich in the low end... you should get it tuned-

 

1k ive tried about 32%-40% past 40 and idle is too ruff. Have not went below 32% becuase the air/fuel read all the way lean and did not move. I Know its not accurate especially down there, but I was trying to duplicate how it read before during idle and it at least bounced some and read something. I might try lower and see what happens though.


[Modified by omahaturbocivic, 4:55 PM 2/14/2003]

 

you sure you dont need to clean out your IACV?...mine idled just like that I took some carb cleaner, sprayed that sucker out and idle sits nicely around 750-800rpm.


[Modified by AztecEJ, 10:35 PM 2/14/2003]

 

I think ill try cleaning the eacv. It was idleing fine before the hack though so I assumed it has something to do with that, unless the hack makes it more sensetive or something.

 

The 450s just take a little while to fully open at idle due to the size.
Richen it up to at least -30% to get a smooth idle.
I find that on my car, -25% works best.

 

Ill try goin that rich then, Thanks!!!


[Modified by omahaturbocivic, 5:49 PM 2/14/2003]

 

yep, -25% is what mine is set to also

 

Mine is set to 59%! And it idles fine! The problem comes at slight throttle

 

i second that
-30%

 

I have my 440cc's -48 at idle and they idle perfect. but my car does the same thing once in a while too. I'll try -30 but that seems way to rich at idle.

 

I tried -30 and it idled fine for several minutes withouht a single stutter, Thanks guys !

 

can the hack idle 550cc's or just the 440/450dsm

 

I know of the hack idling 720cc's, but there were some rich/flat spots on tip in.

550's you should be safe with.

 

You're not talking about the AFC right? It only goes up to 50%. How did you get 59%!?

 

The SMC+ can cut out up to -59%

 

I also have this problem and have tried practically every setting from -25% up to -50% and I still can't seem to make it idle right. The car seems either too rich or too lean, I can't seem to find a good middle ground.

I am going to try cleaning out my IAC valve though, that does sound like it could be a problem for sure.