1MEANGTO

I have a 06 gto I'm tuning with a ms4 cam 239/242, .649"/.609" 111lsa. The car will not return to idle without surging. The rest of the tune is pretty good but thius is just getting frustrating. I've tried to fix this for hours now and can't figure out what I'm missing heres the tune if anyone can take a look at it to try to help.

gametech

iTrader: (1)

If you are an experienced tuner, I don't know what to tell you. If you are still learning there are some steps to make it easier. Bump your idle up 2 or 3 hundred rpm. Not permanently, just as a part of the process. Adjust your desired airflow, throttle cracker, throttle follower tables, etc., until it works OK. Once that works, drop the idle down a bit and repeat. This is a VERY slow trial and error process, but in the end you will have a good running car and a much better understanding of what you did to get there. It is hard to overemphasize the importance of going back to basics when stumped by a problem.

1MEANGTO

I'm pretty experienced but the E40 ls2 pcm's don't even have throttle follower or cracker tables. I've been working with the desired idle airflow and changed most of the idle tables with no luck yet it just doesn't want to IDLE!! It seams not to really respond to anything. Sometimes the changes will help for the first couple of clutch push ins and then it just gets worse the more you drive.

1MEANGTO

Oh thats a efilive file.

gametech

iTrader: (1)

Like I said, if you are already experienced, but are still stumped, I don't know what to tell you. Also, I use HPT, so obviously I can't look at your file.

1MEANGTO

no problem if I get ambitous tomorrow I'll pull the tune with hpt but no promises

1MEANGTO

ttt


ttt

1320FEVER

iTrader: (9)

In addition to what gametech said, try playing with the overspeed table in spark. The stock values are -8*, but I changed mine to -4* and it helped.

1MEANGTO

I have changed the under and over speed but it did not help it in a positive way,

mrr23

iTrader: (3)

did you try the idle in park and drive spark tables? i've played with those. set the overspeed/underspeed tables to all zeros. smoothed out the IAC steps vs effective area and increased the IAC park position airflow. this has helped with using the idle spark tables as being the best cure.

i'm not smart at this at all. just giving you ideas an where to work the tune.

1MEANGTO

I'll take any suggestions at this point. I have tuned many cars with bigger cams and never had trouble until now.

gametech

iTrader: (1)

I'm sure you already have, but have you tried putting the car in open loop to eliminate fuel correction problems? Also, have you tried disabling the maf to make sure reversion isn't screwing with its readings?

Frost

iTrader: (45)

DUnno what they are called in EFIL, but look for the integral and proportional steps the control loop uses; reducing the numbers will slow the response of the control loop and generally helps get rid of that hard loping some...

1MEANGTO

Well I spent several more hours on the car and got some help from a guy in Australia and the car runs like it doesn't even have a cam.

foff667

iTrader: (2)

Mind sharing? Lots of confusion on how to attack idle tuning in LS2's...

mrialsm4

Same problems with the idle here. maybe you could let us in on who "this guy from australia" is? or just post up some changes you made to which tables?

Frost

iTrader: (45)

uhh that post is two years old

mrialsm4

oops.. well I might've gotten lucky!