Any input on fixing this bad SD tune

[Jon01]

Going to help a friend iron out the tune in his car this weekend and could use some input on the one that's in there.
Specs on the car:
99 Hugger Z28
(Engine)
11:1 418 CID (4.07x4.00)
Kateck Resleeved LS1 Block
Kateck Billet Main Caps;
ARP Main Studs;
ARP Head Studs;
GTP Stage III LS6 ported heads flowed over 337 cfm
Custom Ferrea SS 2.080/1.60 valves.
TR custom solid roller cam; 248/[email protected], .647/.647@114lsa
FAST 90 mm Intake;
90 mm nick williams TB;
(Drivetrain)
Spec Stage IV-F Clutch;
Spec aluminium flywheel;
B&M ripper shifter
Moser 9" rearend
detroit locker
35 spline gundrilled axles;
Aluminium center section;
4.30 gears; narrowed 2.5";
(Exhaust)
TR 1 7\8" long tube headers ceramic coated;
mufflex 3" y-pipe w/4" collector;
magnaflow catback exhaust system;
3" QTP electric cut out;

The car does NOT have a MAF on it.
He's been having serious driveability issues with it since getting it back together from correcting other problems. Lots of surging, he didn't say it's had problems dying, just doesn't like to settle down on an idle at all and surges all over the throttle range.
Crazy part is the car put down over 500rwhp and went 10.70's with this tune!
Just want to get a jump on this and try to have something better to stick in it come Saturday. I'll be bringing my wideband over to use during this.
Do you guys think I'd be best off just modifying this one or starting fresh?
Any recommendations on where to go with the idle to try to get it to start settling down?
I apologize for the lack of a log, just haven't had a chance to get one out of it.
Thanks for any input!

[Roy V.]

What size injectors?

[Jon01]

It has 30's in it, once we get this straightened out it will get 42's.

[svede1212]

well one thing i can tell you from having gone thru surging with a lot less horse power is that timing and fueling fixed mine. another thing is when i went from 30# to 42#ers my fueling got more precise especially at WOT. the timing tables look terrible at lower RPM and the higher RPM should have a little dip at peak torque instead of being flat. look at my timing table. i run SD with no MAF

[miami993c297]

well one thing i can tell you from having gone thru surging with a lot less horse power is that timing and fueling fixed mine. another thing is when i went from 30# to 42#ers my fueling got more precise especially at WOT. the timing tables look terrible at lower RPM and the higher RPM should have a little dip at peak torque instead of being flat. look at my timing table. i run SD with no MAF

Hi svede1212,

Your Bin file is looking really good, lot of logging / analyze and adjustment there...

Do you have a recent log going with your Bin driving around?

Christian

[svede1212]

here's one. i wonder if you ever get "done" tuning . i've been tweaking on one tune or another ever since i got my suite March '06. it's addicting. i have a fair sized cam 228/232 .612/.600 111 lsa. i've included the cfg file as i think you may need it to view the log correctly

[Jon01]

I had a feeling those big blanket changes to the spark tables weren't the right way to do things at all.
By more precise do you mean it required more precision to get the fueling spot on? Or that it was easier to get where it needed to be?
You're right svede, it is addicting! But it's fun constantly improving on things.
Thanks for the input!!!

[svede1212]

it took a lot of logs for me to get the fueling spot on and that helped. for timing i started with the stock table and used RTT with a driver to tweak the timing to eliminate bucking at lower RPMs. on mine the row for WOT g/cyl are at about .76. i think you need to go back to square one with the timing table or at least use a table from comparable mods as a starting point.

[Jon01]

Thanks for the help svede. It looks like he's going to be putting a MAF back on it this week which will make things much easier for me. Especially getting things dialed in with the new injectors-which if you check about 22:10 of the log you'll see are very much needed.
Have a couple perplexing issues I noticed yesterday afternoon and got a log out of the car. Bad news is, I was all doped up on cough medicine and didn't think to reconfigure my scanner for the car's lack of MAF. I know some of the information needed isn't there and I apologize.

Really what concerns me is the TPS jumping all over the place. Any input on this?

I'm having him double check the setscrew and TPS sensor to make sure they're cinched down. The surging really seems related to TPS jumps though.
I was able to smooth it with the VCM controls-commanding the AFR, then pulling 8-9* of timing. I further noticed that when I pulled the timing away the TPS seemed to settle down at 1%.

It started pouring which cut things short but I think I have the idle problems figured out-to settle it down would I just need to get the idle afr leaned out and pull 8-9* of timing, correct?