fevoman13

just finished putting a f1c on a 08 ls3. mods are exhaust, cam, holley hi rise, full fuel system aremotive 1000. problem is the tuner came over got everything working great but it surges at idle. the tial bov pulses open with the surge. now if i take the hose off the bov (one going up to the brake booster) it stops surging and runs great. bov flutters and trys to open when boost builds and releases. im stumped anyone know what can fix this???? spent hrs searching but cant find anyone having this problem thank you.

Unreal

Find a new tuner.

fevoman13

he has tuned plenty of other boosted vehicles including vettes. so you
think its in the tune? just weird how as soon as i take the boost line off the top of the bov it smooths up.

Kadorja

You have the correct spring installed? Should be a 2psi green spring.

Unreal

Even without the "correct" spring it should not do this at idle if the tune is calibrated correctly.

Irocz2173

Unreal,
Please suggest a "new tuner". I am in detroit metro, Michigan and would be happy to bring my car to a shop that you consider capable of tuning a boosted vette. I'm sure the OP would do the same but i don't know where he is from.

Unreal

I am not a repository of tuners but surging is a tune issue. If his current one can't fix it then time to find one that can.

Livernois is in that area I believe.

mourat

Tune issue for sure. Try a few simple things in HPT -

1. Turn off Dynamic airflow by setting high RPM disable to 300 and enable at 200.
2. Put back original timing idle overspeed / underspeed settings under spark.
3. Bump RPM up to 900 at least.
4. Change ETC area scalar under idle up and down 15%

What injectors do you have? If they are Injector dynamics, make sure that all your injector values are exactly how ID recommends them including minimum injector pulse width set to around .125 etc... Maybe you posting your log file and tune will help.

If the above fail then try disconnecting the MAF to see if SD mode runs better. If any of the above fix your issue or make it better, then you need a new tuner.

SlowBusa08

always a fan of following up a suggestion with useful things to try.

Unreal

Fair enough

Find a new tuner that knows how to adjust idle tables.
Idle air flow
Idle VS ECT
Idle timing
Over/under RPM

SlowBusa08

also a legit response. some of us aren't so lucky to have great tuners with experience in tuning big hp boosted cars so I have some empathy there.

On the flip side, there's a reason good tuners are highly sought after...

Unreal

These "help me" post without a lot of info are always hard or impossible to help with. Someone should start with the basics, or we assume that has been done.

Boost leak, vacuum leak, TB operating properly, plugs, wires, etc. We can only assume that the tuner at least looked at that before tuning it, and it isn't a mechanical problem. So start with the basics, but idling is all in the tune, and if it was a leak/etc he should have seen it as he tuned it if he knew what he was doing. So it all goes back to find a new tuner or a decent shop, and take there.

Or start with the basics, and tell us what you have ruled out. If you don't have those skills, then goes back to find a shop/tuner that does so they can help you.