ok, I have a 99 si and it's turbo, i put in a set of 440 cc injectors and a did vafc hack to run the injectors. The car starts on the frist try but it idles about to 400 to 500 {which is very low} and when i give it gas it studder to pick. I can't even drive around the block. My setting are all the same on lo/hi and narrow /wide. I have the vafc2 with the black face and the TH-POINT is set at narr. 10% and the wide is 50%. what is the low and high here. Should i set it to 98% low and 99% high???like the older vafc...any help here...
1-2.5k -40%
3k -40%
4k -35%
5k -35%
6k -35%
7k -35%
8k -35%
9k- 35%

 

Change the setting's at one k to where it idles the best. I have my freind's b16 everywhere else @ -38%.

 

Well, if your car is idling low, idle it up a bit with the idle adjustment screw. See if it helps with throttle response.

 

yeah i did that and it will idle were it should be but if i give it gas it studders. i don't know what it can be,maybe i need to play with the vafc setting a little more???

 

for idle you might have to go as far as -43

 

sorry to bring this back from the dead, but im having the same studder problem as dynasty-x-motorsport. can anyone tell me how to fix it. i have a 2000si with greddy 18g with rc 440s. thanks guys!

 

its either too little or too much gas. change teh setting 10% each way at idle and see if it helps.

 

i had mine at -36% for the idle. dont be afraid to touch the 1000 seting you wont hurt anything. dont forget to retard your timing at the dizzy

Landon

 

Typically when an engine is coming off idle and it stumbles its because its too lean. If you don't smell any raw fuel that is most likely your problem. Add some fuel down low.

 

i thought it was too much fuel, cause i was puffing alot of black smoke.. anyone else can tell me?

 

In my experience you get poor tip in off idle due to being too rich.

Given the variances in stock fuel maps between engines, I could only get a good consistent idle by bogging my LS with fuel, -25% at 1000 rpm. The tip in was worthless, I'd just blip the throttle twice quick to pick up the revs before letting out the clutch. It's a hack, depending on ECU/engine/setup you aren't going to get much better than that.

 

I think their is some confusion as to what I'm trying to say (i'm poor with words).

Last night at the track I filled up with some race gas and leaned out my ENTIRE fuel curve 10% (even at idle) because I was to lazy to properly curve things. When I would stab the gas to bring the revs up to launch the idle would drop, allmost stalling the car. The engine would slowly studder and finally build up to 4000rpm's or so, so that I could launch. I went back to the pits and added 10% back in and I was back to normal.

Now, when your running too rich at idle the car just smokes. You go to stab the gas and the RPM's don't die but build slowly.

See in both cases performance off idle is poor. Maybe I am still not explaning it correctly but when I'm in a car I can tell and make the necessary changes.

What you really need to do is watch your narrowband output. Try to get the car to swing around 0.5v on the narrowband.

 

i think it does that both when its running too rich, and too lean. try give it 10% more than normal and see