wmskateteam

iTrader: (8)

i've done the search and can't find what i'm looking for.
my car is surging in neutral only when coasting/rolling. for instance if i'm coming up to a light i'll throw it in neutral and then the RPM slowly climbs from 1 to sometimes 3k, once i come to a complete stop it will idle normally or if i push the clutch pedal down it will go back to an idle, like it should. it idles fine, no issues. if i leave it in gear when i slow down it won't increase as much but the RPM never really drops either. I don't know if this is a tune issue, pedal position calibration, I have no idea. the car has an alum flywheel, is it possible the lighter weight hasn't been accounted for in a tune? i'm really trying to learn what's going on so i can fix the small issues with this car. thanks in advance

wmskateteam

iTrader: (8)

any ideas?

Razorecko

sounds like you have the new V w/ stickshift. I do and mine does the same thing = normal

wmskateteam

iTrader: (8)

no, it's a v1 with a maggie, but that's interesting your v2 does it. so is this common problem?

07CTS-V

iTrader: (6)

Try cleaning your MAF sensor and checking for any leaks in your intake tube connections.

whisler151

Mine did this. My tuner was able to fix it. I forget exactly what it was though. Something about decel I think.

07CTS-V

iTrader: (6)

I just re-read your original post. The tune needs to be adjusted for the lighter flywheel.

wmskateteam

iTrader: (8)

thanks, i'm not sure if it was ever re-tuned so i guess that will be my first option.

4doorvetteLV

iTrader: (1)

Dont know what it could be with a maggie, but it sounds exactly like an overbored throttle body problem alot of us have had.

wmskateteam

iTrader: (8)

4door, what was the solution? was this the overbored ls6 TB? did you go with a LS2 TB? What should I look for?

raven154

iTrader: (14)

Sounds like you have a vacuum leak somewhere. Do you have a ported TB on the car?

wmskateteam

iTrader: (8)

i have a ported TB, i will look for any loose connections or dry rotted hoses, i bought the car like this, so it's not like it happened all of a sudden or I messed with something it started so I appreciate all the input. so I will look up:
overbored TB issue
vacuum leak
if a tune is necessary after the aluminum flywheel installation

has anyone ever had the same symptoms?

4doorvetteLV

iTrader: (1)

I have the ls6 TB and ordered a P&P'd throttle body. It surged like yours but since you got a maggie, it could be a plethora of other things. If youre getting a tune for the FW then that should work out the TB issues as well though. Check the other vacuum lines too so you arent wasting money getting the tune.

JNR_Design

iTrader: (3)

if you suspect a leak, get a vacuum gauge and take a reading, then go from there...should be in the 18" range at idle I'd imagine, since you're at sea level-ish. Also, the behavior of the gauge can tell you things, as well; should be steady whilst it idles.

here's some good info to use as a tool

wmskateteam

iTrader: (8)

didn't find anything on the overbored TB mentioned, did a visual check on lines and connections, will try to get a hold of a vacuum gauge

wmskateteam

iTrader: (8)

so I got a hold of the previous owner and he stated it did it the entire year he owned the car, he said he was told it had a road race tune so it was ready for downshifting. i've never heard of anything like this, but i have hopes of being able to tune it out. i'm also replacing the TB with a ls7 unit so the blade turns the same as the ls6 and i'm getting the snout from magnuson (on backorder)

4doorvetteLV

iTrader: (1)

Road race tune?!? That's crazy talk. Good luck man, you're on the right track. Hope the maggie snout comes within a decent time frame for ya.

wmskateteam

iTrader: (8)

exactly what I was thinking, haha