Help with tuning my cammed 6.0L LQ4 jet boat swap please!

[Wasted Income]

http://www.youtube.com/watch?v=5qI0BsAc9WI



Routed the LH exhaust up, thru the transom for tuning purposes, put the wideband down inside like on the dyno. Runs pretty good at idle, but wasn't able to log much wideband data at speed, because the first time I stabbed the loud pedal, the sensor came rocketing out...and into the water. D'oh. Gonna put a bung in and try again, lol.

[Wasted Income]

Well, I haven't had a chance to AutoVE yet, but I swagged a tune close enough to be able to take it out and play this weekend




Runs good other than:
1) When I chop the throttle from speed, the engine dies.
2) Also, I am still getting a pretty serious surge at idle, after giving it a little throttle input around the docks. Will surge hard enough that it will die most of the time.

Can anyone look at my latest tune and give any suggestions as to what to look at next? I just did the RAFIG process yesterday. I don't have a log from these events...was out to drink and play, not tune, so....

Thanks in advance guys!

[5.7ute]

Have a look at B5935 & B5936 idle underspeed error. I wuld try lower this by at least 50% & see how the idle surge goes then. (Just an uneducated guess without a log)

[swingtan]

+1 for Idle spark control. It looks a bit aggressive and may be over compensating and causing the surge to worsen. What I normally have is something like the following...

LABELS Idle Overspeed Error (Degrees)
RPM {link: SAE.RPM} Value
0 0.000000
13 -0.373535
25 -0.812988
38 -2.526855
50 -5.493164
100 -7.514648
150 -7.998047
200 -7.998047
250 -7.998047
300 -7.998047

and...

LABELS Idle Underspeed Error (Degrees)
RPM {link: SAE.RPM} Value
-300 7.976074
-250 7.998047
-200 7.998047
-150 7.998047
-100 7.998047
-50 7.492676
-38 4.526367
-25 1.472168
-13 0.373535
0 0.000000

I'd also add more min idle air in B4307. Put it up around 8gm/sec at normal operating temps.

Remember that the engine will always want to have some amount of RPM drift, dependant on the cam specs. When the idle is tuned well, you wont really notice it unless it's a massive cam, but you can see it in a log. My E38 managed, cammed 6Lt seems to want to hunt +/- 50 to 70 rpm, but you cant really tell. I was looking at an LS1 with a baby cam last week and drifted +/- 30 RPM. Again. you could only really tell by highlighting the idle RPM in a log. I'll get some pics up when I have a chance.
Some logs would also bee very helpful....

Simon.

[Wasted Income]

Thanks so much for the input, guys!

I will tweak those tables you suggested and hopefully be able to take it out tomorrow and do a little logging.

Getting close now!

[ScarabEpic22]

Should have put a Duramax in it...

Cool project though, Im in the middle of researching an engine rebuild for our '87 Wellcraft Scarab I O/B with a Merc Laser 220hp EFI motor. If it was the I/O version, it'd have probably an LSx or 454 in it but being an outboard, Im at the mercy (and I mean MERCY) of Mercury's first attempt (and I mean ATTEMPT) at EFI. The dang ECU is such a POS, dont even get me started. Least there's 1 guy who has built an aftermarket plug-n-play ECU in 2 flavors, fully tunable via knobs and PC datalogging and the more basic one with a good tune for your motor and mild adjustment. Wish I could just slap an LS1 PCM with an S10 cal on it and be DONE, but no idea how Id make that work.