Ilikeppie

iTrader: (5)

alright so i put a fairly good sized cam in the 230's ported heads headers full exhaust ls6 intake and a few other odds and ends here is the problem the car will idle pretty good but if it has to set too long it will almost die out then surge? i could see this problem but it idles fine for a good while then starts surging. also if i am just idling around a parking lot (rolling around in gear not pushing in clutch or on gas at all) and it starts bucking harder and harder what can i do to correct this im using HP Tuners. another thing is i keep throwing a ses light for egr cause i eliminated it and we turned off the codes but it still comes on? any way to correct this thanks all

Caspernicus

iTrader: (5)

Sounds like the fueling is off.

What have you changed?....besides deleting codes.

Ilikeppie

iTrader: (5)

im not sure what all we have changed its me and a buddy and they have been doing the tuning but im sure we have adjusted the fuel map spark curve stuff like that its running great but the idle is just pissing me off

DaveX

Welcome to the world of driveability tuning. It takes time and knowledge or hours of experimenting to get it right. Airflow is a common culprit, and fueling and timing.

Ilikeppie

iTrader: (5)

figured i would bump this up not getting much info

Ilikeppie

iTrader: (5)

anyone?

01'WS6

Do you have a wideband on the car?

Ilikeppie

iTrader: (5)

no but i can access one on the dyno if needed

onecamaro1

What do you have the idle rpm set at? As far as EGR, just uncheck the ses light enable and turn to no error reported.

edcmat-l1

iTrader: (10)

couldnt have said it better. making power is the easy part

Ilikeppie

iTrader: (5)

the idle is set at 950 and i know this drivability is gonna be shitty just wondering if anyone has had similar problems or can give me some pointers to dial it in

Ilikeppie

iTrader: (5)

edcmat-l1 it says your a efi specialist what sounds like you guys know what your talking about what advice would you be able to give me

01'WS6

Ur fueling is apparently way off.

Ilikeppie

iTrader: (5)

fueling at a idle? when we did the dyno tune the wideband read a good fuel air mix

vaticano

iTrader: (8)

Maybe Desired Airflow, Throttle follower, Throttle cracker. These are usually related to idle problems. I read somewhere that if you raise the timing in the lowest map 0 rpm area of the timing table it can help with idle issues, I do believe it was more for fast idle while rolling in neutral but more info is better then less. Mine used to buck at low speed but was due to running way to lean. Good luck

Ilikeppie

iTrader: (5)

hey thanks for a reply that i can actually pull from maybe this will help dial it in a little better

vaticano

iTrader: (8)

No problem. You should try to get a wideband it will help a lot. I just reread your origanal post. One more thing to check, would be to log your MAP values at idle and let it heat up and see if you get a change in MAP pressure. Mine will run great for an hour or so then out of no where it runs real lean and the MAP value increases 7kpa. I have checked for vacuum leaks and can't find any, so I have to pressurise the intake and see if can find one that way. It only does it when the all the parts get hot. Sounds alot like what you desrcibed.

01'WS6

Incorrect fueling is the major cause of surging/bucking and this is including idle surging. Fueling has everything in the world to do with a good idle. Most people try and jack the timing sky high trying to cover up the problem but its not the correct way and doesn't always help.

RedHardSupra

iTrader: (1)

surging is overfueling. big cams cause overlap which given enough time (aka low rpm) can allow fresh air from intake to leak over to exhaust side and confuse the WB. with big cams, at idle, don't listen to the wideband, just sniff the exhaust, listen to your engine, and watch the MAP.

01'WS6

I have found that it has to be a pretty big cam to actually throw the wideband off. I'm running a 233/239 .605 .610 cam and the wideband is pretty dead on. U can defiantly see the lean spikes from the fresh air on occasion but not enough to not utilize the wideband for idle fueling.