Chronicles of idle tuning LS1/big cam

[mecanicman]

open the scanner and load the russ k config. Turn key forward and connect with scanner. Start scanning, then start the car on without touching the throttle, ac off. Allow the vehicle to run until it is fully warmed up. The histogram creates an airflow value for each temperature in your RAF table. Make sure your units are the same(imperial vs metric), copy the data out of the cells in the histogram and paste into the corresponding cells in the RAF table. Save. Flash. Done.

[detroit]

I had some sucess with making those lower values the smae or close in the VE table, so when the idle dips it does not have a big transition to deal with.

[Rinkrat456]

mecanicman, do you ever log off? Seems like you're always on this site lol. I feel like I am too some times.

Anywho, I've got the car all night and tomorrow. I went out driving to get a feel for what it does right now and in addition to what you've already recommended I do, I have to fix another idle-related issue.

It seems that only after the engine is heatsoaked and for sure up to operating temperature (driving in the city and up hills for example), that I have another idle-issue. The engine goes into cruise control mode injecting tons of fuel. I suspect my VE table, but I'll keep describing the situation. It gets worse the longer I allow it to, the idle goes waaaaayyy up (2500-3000) for awhile and if the M6 is in any gear it goes on cruise control mode. Say if I lug it into 6th gear at 30mph the car will simply accelerate. When I push in the clutch or neutral, rpms skyrocket, then eventually it will return to normal idle, but eventually it'll go back up to above what it skyrocketted to before (say 3000-3500 this time). It's almost exponential.

Tomorrow morning I can apply all the idle suggestions you mentioned, do a RussK config to dial in RAF, then I'll go driving hopefully to recreate the situation I described above. It's quite annoying when you're trying to come home quietly into the neighborhood when idle is above 3000rpm through 2.5" dual Magnaflows.

[Rinkrat456]

Working with the car right now out in the driveway.

I flipped the TB set screw so it's easier to dial in. I screwed the set screw out a few turns until voltages were at .65V for TPS. I reset the TPS and IAC so the TPS reads at 0%.

Currently performing the new RussK idle config to dial in RAF, but I notice right away the IAC desired is still at 310. Does this mean a hole in the TB is necessary?

I'm including a few logs from a drive I did to the parts store to pick up the T15 torx bit for the set screw. It outlines in the first 7221 log that surging situation I described last night.

Also included is another log file (7222) that shows the low idle situations when clutch in. Tune attached.

[Rinkrat456]

Newest tune with a few more TPS adjustments. Raised idle to 950, was hoping for a little lower. IAC still looks maxed out around 310 until the last time I adjusted the set screw, but TPS Voltage was up around .85 and idle wouldn't come down below 1050rpms...but at that time IAC was a lot more fluent ranging from 0 to 310, most of the time settling in the low 100's. Does this mean a hole is necessary in the TB but not a very big one?

Also disabled PE, raised fan temps a little and dialed in VE pretty close. Not 100% yet. Also returned many of the throttle cracker and follower settings back to 100% bone stock for LS1 '02 Camaro. See if that helps my surging idle issue any.

[mecanicman]

You have not said what tb is on it, have you tried loosening the tps screws and turning it back? There is usually some play, or the screws holes can even be elongated to allow rotation(carefully).

[Rinkrat456]

I honestly don't know what TB is on it, but the owner bought the LS6 intake and ported TB together, so I'm assuming it's just an LS6 TB or perhaps an LS1 TB bolted to the LS6 intake. Looks exactly like the one on my 5.7(5.3) with truck intake, just bigger and shiny.

Okedoke. Car is running extremely well compared to last night. Idle is more consistent, doesn't dip below 800, comes up reasonably quick, and I haven't experienced the high idle surging in my previous posts now that all VE fueling is +- 3 around idle cells. It idles at 900, which is fine. I performed the RussK RAF idle config every time I made adjustments to fueling and the TB set screw (TPS Voltage and relearn process a number of times, now set at .69V @ 0% TPS). Each time it seemed like IAC would get better and better, dropping from 310 to low 100's. I noticed I had the fan settings too low, so I set them higher more like a stock LS1 Camaro (even though this particular radiator setup only has one 16" fan). I noticed that idle would surge high when the fan kicked on, so I reduced the cooling fan idle airflow to 0.020lb/min and since there's only one fan I set both Fan1 and Fan2 to the same.

See tune 8.3.

Thank you, mecanicman for the guidance. I'm not done yet, and this August's upgrade is nitrous with new heads and cam ( means more work for me) so I will be back on this for sure later. For now, it's night and day more stable than this morning.

Dialed in the VE table quite a bit, played with PE some.

[Rinkrat456]

Went out hunting tonight in the car for fun.

Race1 and Race2 is against a '92 Corvette with a 700r4 and some 361ci circle track modified engine...not really sure.

Race3 is against a WS6 LS1, specs unknown...looked factory.

Viewing the logs I can see the LS1 is almost out of injector, as it hit 88-89% during one of the runs. But what I'm most interested in is how most of the time around WOT the timing was set as factory around 23-24*. Don't LS engines make best WOT power around 27*? Anywho, I may be doing some reading on spark tuning now that I noticed that, but at least here are a few logs to check out...the last two are short. If you notice anything crazy out of wack let me know.

[oakley6575]

Any luck with the IAC counts?

[Rinkrat456]

Yes, and in fact I got the engine to behave very well...which lasted all but maybe 2 weeks until the owner got sick of the LS1's power and is currently building a forged 370 with a TC76 turbo lol. I'll have to start all over when the new engine goes in.

If I can be of any help though shoot me a PM, as I've recently played with a few big camm'd engines over the summer and got the idle step-by-step down pretty well.