xSandbagger

I have a 2000 C5 M6 with a TSP MS3 and a CAI, otherwise power train is stock. I am running in speed density mode (tuned using AutoVE process) and I have been able to tune the car for good WOT power and it idles fine. The problem I am having is after a few seconds in any gear below 1700 rpm she starts to surge and if I don't press the gas or ease off it gets progressively worse until it is jerking/lurching violently . If I press the gas she accelerates smoothly. When logging with EFILive I notice that when this problem starts the timing starts to vary similarly.

Any help would be much appreciated.

onecamaro1

post a log please.

Slowhawk

iTrader: (12)

When you push in the clutch does the idle hang at 1800rpm or so?

Country Boy

iTrader: (24)

Its generally a timing or AFR problem.... or both.

Billdog350

iTrader: (3)

Did you change injectors? I have heard that larger injectors sometimes can't handle a small pulsewidth and will cause that problem by jumping too rich or too lean since they can't handle a "small" squirt of fuel. I have 42# injectors right now and occasionally my car will buck like you say...but most of the time its perfect.

KRAZY K 2000 TA

iTrader: (5)

i was going to say timing log it and i bet it is jumping around right there,mine was i tried to get it evened out in that area and the problem went away

SSpdDmon

iTrader: (10)

I got rid of mine with the following....

Timing - Base Spark for 0.08~0.24 grams/cyl
400rpm 24*
800rpm 24*
1200rpm 22* (yes, twenty-two degrees)
1600rpm 24*
2000rpm 27*
2400rpm 31*
2800rpm and up 34*

Throttle Cracker
400rpm 6 grams/second (stall saver)
1000rpm 0 grams/second
1600rpm 0 grams/second
2200rpm 0.75 grams/second
2800rpm 1.5 grams/second

Try that.

You'll have to redo your RAFIG from a cold start. Before you flash the changes above, add 1 gram/second to your Desired Idle Airflow (base running airflow in HPT). Then, flash changes and redo RAFIG.

zapp168

iTrader: (7)

My car started doing that right after going with 60# injectors. As far as I know everything else tunewise (other than IFR) was the same in the lower RPM range.

xSandbagger

Thanks for the help guys.

To answer some of the questions:
It doesn't hangup when I sink the clutch.
I haven't changed the injectors.

SSpdDmon,

I tried your suggestion but still doing it, I think it might be because I need to go beyond 0.24 grams/cyl so I am going to try that and see how it does.