The car: LS3 Swapped 1989 Formula, 550 crank HP, 440 RWHP.
The cam: 232/236, .600 lift, 112 LSA
The transmission: 4L60E, Yank 3400 9.5" converter
ECU: GM Factory unit from a 5.3 Silverado
Throttle Body: 92 mm Nick Williams, cable driven

The problem: Tuning issues. The car has been to three different tuners in Vancouver and Tacoma, WA, and the issues have not been resolved. The car seems very happy at 100 mph, but seems to lose patience in town with traffic.
The issues: Apparent inability to thread the needle between too much idle air (car will idle at 35 mph), and too little idle air (car will have a tendency to stall in certain low speed conditions). The [too much idle air] situation has been tuned out, but the car will stall in some low speed conditions (especially reversing) unless the throttle is managed just right. The latest tuner (Turbo Technologies, Tacoma, WA) has arrived at the cam being "too big for what I want to do". For the record, what it is I want to do is to simply not have "hiccups" in stop & go traffic, or, at the very least, to be able to reliably back into my garage or into a parking space without stalling. Also, these issues are sometimes accompanied by P0121 codes (TPS voltage crap).

I've been considering going with a looser, higher stall converter, due to concern that the current converter may be defective or just wrong, but the fair point was made that doing so could be just an attempt to mask an underlying tuning issue. And the transmission/converter experts I've talked to have said that the existing 3400 stall converter should be right.

As for the tune, first two tuners I used were in Vancouver, WA, four (4) hours away from me. The latest one in Tacoma is 2.5 hours away. This adds to my frustration and hassle.

Anyone have any advice?
Anyone experienced similar?
Anyone know of any good tuners in the Pacific Northwest?

 

I would suggest purchasing hp tuners then anyone can help you remotely or through email. Its a great investment if you have a modded car, its great for diagnostics and troubleshooting and of course tuning.

 

This is the way to go. That cam is large enough to require a bit of time to really nail down driveability. Time is something experienced tuners want a lot of money for. If you really want a happy driving experience with your car, you need to be able to make changes yourself. Even if you send datalogs to somebody else to make changes, this is far better than having to drive to a tuner anytime you have a problem. That being said, learning to tune for yourself is very rewarding.

 

And another thing, chopperdoc has posted some great videos for free now that are really helpful, that people used to pay good money to learn. (me included)

 

FWIW...

I've got a 232/234 at 112 with .600 lift, so pretty similar specs, but on a 5.7L, so a bit less displacement, so it should act like a little bit bigger cam. LS2 DBW throttle body, manual transmission.

Straight from the tuner, idle and return-to-idle were both pretty unreliable. When coming to a stop or maneuvering in parking lots I was constantly working the throttle with my heel while I was braking with my toe. The tuner said he'd tried and tried and that was the best he could do (Josh @ Corvettes of Auburn). His theory was that it's the injectors (Bosch 42# from Deatschwerks) and he needed more data on them to get them to behave properly.

I ain't going to argue, but after a bunch of experimentation on my own, it is working much better... not perfect, but much better. Idle spark advance is 19 degrees (originally 25) and base airflow is 18 g/s (originally 8). Now it generally idles pretty smoothly at 850 RPM, with just a hint of lope. Coasting toward a stop, the RPM will drop to 1100 or so, and when the car comes to a complete stop it settles to 850.

But, still... once in a while, when I put the clutch in, it just dies, or sometimes the stall-saver kicks in at 400 RPM and it narrowly avoids dying before finding an idle. Which is still annoying, because it shouldn't ever hit the stall saver in the first place. The inconsistency is really annoying. If it was consistent, I'm sure I could tune it out. But it mostly works, so I'm left wondering why it sometimes doesn't.

So anyway, I share your pain and I don't think either of us has a too-big cam. Idle tuning is hard though, at least for GM. With 2004-and-later Subaru, we basically just tell it what RPM to aim for, and what throttle opening angle to start from, and it learns the rest in a minute or three. I had no idea how nice that was.

Based on those travel times, I'm guessing that you're north of Seattle? If you find a tuner who can figure out your idle before I figure out mine, I might want a word with them.

 

That large of a stall esp on a loose 9.5" should not have one single issue with auto cruise control though.
Like lsx power tuning said, purchase a remote tune pack and work from there. It will help you learn at same time.

 

That cam and stall should be straightforward to tune. If anything I'd bet the throttle body has more issues lol.

 

1) Make sure your IAT is reading correctly. Check it first thing before a cold start and make sure IAT and ECT are close to ambient. There are two different curves between the older and newer ECUs/sensors and a mismatch with skew the SD calculation a bunch as temperature changes.
2) Confirm that the VE (or virtual VE) table/coefficients were dialed in with proper steady state tuning on a load bearing dyno. Even if you're running off the MAF, getting this right greatly improves the accuracy of the airflow estimate used for both fueling and spark.
3) Please tell me you have injector data that is 100% accurate for the hardware on the engine.

 

I run a similar sized cam in a 4.8. A couple degrees less duration with about the same lift and on a 110 LSA. Also run it on E85 with a cold plug.
Idles fine. Starts right up. Idles at 1100 cold and 900 warm. It idles ROUGH but has amazing throttle response and I don't have any issues with stalling.
Street mannerisms are good enough for a daily.

I've always had issues with IAC tuning on aftermarket throttle bodies.
They can definitely be solved, but one tuning session won't do it.
I usually have to sit in the driveway or a parking lot for an hour or two at various desired idle speeds and throttle blade preset to get it perfect.

 

I've gone through this before, it's in the tune. When I went 90mm on my LS6 car it completely threw everything off and took my tuner a lot of time and effort to get it closer to where it needed to be. I'm still not happy as I'm still having issues but fortunately much less so. One thing I've realized is that some of the so called pro tuners including some of the tuners that sponsor this site (none of which has posted in this thread so far so not taking any shots) aren't as amazing as they claim to be. I wonder if you put an OEM LS3 throttle body on there if that may make the tuning a bit easier.

 

I've fixed some of their tunes and can confirm this

 

You sure you dont have a vacuum leak somewhere?

 

If you're ever in the Philadelphia area let me know, I need mine fixed too haha.

 

I went through exactly what you are going through.
1) the nick Williams tb is causing your your tps code issue. I had one and the throttle shaft was machined incorrectly. I sent it back and nick found a loose fit between the shaft and the tps...you cannot have slack there.
2) your timing needs to be adjusted. in my tune, I have the timing in gear at 27 degrees from 0rpm to 1200 rpm, the same number for all cyl airmass. in park its at 26 degrees. in the high octane and low octane maps, 0 to 800 is 26 degrees, 1000rpm is 27 and 1200rpm its starts a transition to the rest of the map.
3) You need a proper idle air histogram created and a log on it from cold to hot....once in neutral and then the next day in gear. That gets your proper idle air nailed.
4) FUELING. THIS IS VERY IMPORTANT! if you do not have the proper fueling in the idle cells and you have a large jump in fueling from one load or rpm to the next cell, it will never idle correctly.

once these things are nailed, you more on to your idle air adders, throttle follower, throttle cracker, rolling idle....etc etc.

I know you have no idea what i'm talking about because you dont have hp tuners. But If you want something done right, you gotta do it yourself.

 

 

I have NEVER seen a true nick Williams tb have shaft issues and ive sold literally thousands and tuned hundreds. I have seen some knock offs marketed as them though. Ive seen other tbs have issues with many things, but i would never question a nick Williams.

 

Ummm I bought it from the ws6 store. I called there several times about it. I wanted my money back after all the headaches I had with it. That wasn’t an option. I was then I was directed to deal with nick Williams directly. I wasn’t treated badly, it’s just not the solution I wanted. I still have the emails between me and mike Kaser, Nick Williams and the videos of the problem. After numerous emails, phone calls and waiting, it got resolved. The shaft was too loose in the tps. So for you to say that ws6 store never have a problem with one is not true. I just looked and I still have all the back and forth emails.

 

I said me. Not ws6store. And what you said originally is slightly different from what you just said. Im not mike also.
Still, over the hundreds we sell and the thousands they make and others sell, they by far have the highest quality and least issues.

 

Wow...that was quite the cop-out considering you post under the name "tech@WS6store". That answer will really make us want to buy from you in the future. Just admit the mistake, apologize for the confusion, and move on.

 

No cop out. I am sorry for your unicorn experience, but its definitely not the norm and i, myself, have never seen it happen. Ive given my actual history of the instances i have. There is no confusion.