PontiacBonnevilleClub.com

The scan looks close to the others where you had minimal KR so I'm sort of scratching my head as to why things have gone backwards. What do your spark plugs look like?

I'm at work now so I can't check them until tonight. This is what's been bothering me. One run it's fine, another it's off the charts. Want me to send you the scan file? I have 24,903 frames logged from this morning.

Sure, I'll take a look at the specific lines where the KR occurs.

I only had time to take a quick glance at the latest scan. For the most part it looks likes the detonation that's occuring while in PE mode is because of the engine running lean. The O2s are all hovering around the 900mV mark...I don't even dare to run that lean with an intercooler. Double check your commanded WOT AFR settings. Also, the injector pulse width is erratic at WOT for some reason...varying from 14-20msec. The most I've ever seen mine vary was by ~2ms, and the fueling was spot on despite the change in IPW. The other thing I'm seeing is a lot of KR occurring while the manifold pressures are within the range that you'd see under normal driving. I don't think it's false KR, though I can't find a pattern or reason for why it's happening. Something's going on in there that shouldn't be happening, that's for sure.

I'm confused, how can I be running lean if my LTFTs are showing -1 to -2 ?

Here are all my PE settings:


Spark Control / Advance settings:


What should I change?

The LTFT is only the change in IPW the PCM needed to hit the desired AFR (correcting for fluctuations in individual MAF sensors, inaccurate tables etc.) The commanded WOT AFR can be 13:1 and you can still have LTFTs of 0 across the board despite running a dangerously lean mixture for an FI motor.

Your commanded AFR is set to 12:1 (Power enrich fuel base vs. ECT), bump it down to 11.5:1 for ECTs 158 or higher, then reset the fuel trims. Also, try feathering in the PE enable TPS some more...maybe 45% @ 1600rpm, 40% @ 2000rpm, 35% @ 2400rpm or something along those lines. It takes the PCM a little bit to catch up to your right foot so it doesn't hurt to give it a head start.

Thanks Aaron!
a) Changing PE vs. ECT from 12:1 to 11.5:1 and up
b) Changing PE vs. TPS to 45% @ 1600rpm, 40% @ 2000rpm, 35% @ 2400rpm
c) Resetting fuel trims

I'll write the new bin tonight. Car pooling tomorrow (not driving), so I'll have new data Thursday morning.

Gary's write up (http://www.hollandms.com/newbie/tuning_new.htm) enriches the PE vs. RPM vs. Time table. Is that just another method?

You'll get to that table later. It's used to stabilize the fueling during extended WOT runs, and the narrow band sensor isn't really accurate enough to dial it in properly. All of those correction tables are a pain to get right, because it's mostly trial and error. As long as your O2s fall within the range you want, you can leave them stock.

Don't expect thing to magically get better during the scan Thurs. Things need time to settle anytime you reset the fuel trims, which should be done anytime you touch something fuel related (including the MAF). You should see your O2s go back up around the 930mV mark though. Friday would be a good day to get a longer scan in, like the one you just did. With any luck you'll be ready for the track on Sat.

Great! Thanks so much!
I'll write and reset trim tonight, do a little local driving, but Thursday, I'll have 2 long drives (20 city miles to and from work).
Hopefully, we'll be close by Friday. Also, hoping Casper's will have my hot wire kit in my hands Friday.
btw, new EVAP canister on order.

I can see now how people blow up these engines while trying to tune in that extra 10 hp.

2000Silverbullet wrote:I can see now how people blow up these engines while trying to tune in that extra 10 hp.

Maybe he should just turn the fuel pressure up

Let's keep this on track for Ken guys. So far it's a great thread with tons of good info for those considering tuning.

This thread isn't about dialing in that last 10 horsepower. It's about tuning the KR from a motor to run KR free while optimizing what the factory can not. If you blunder through trying to learn by making changes w/o understanding the ramifications you can easily blow a motor. Tuning with assistance, guides and asking questions is the right way.

Things look great Ken, I'm glad Aaron is helping you with your tuning as I haven't done enough tuning to step up to the task.

I'll never try for that extra bit of hp...isn't worth the risk imo. I'm in the camp that doesn't like to see any KR despite the excepted notion that a little bit of it is normal, so I keep the tune conservative on my own car. Ken's not to the point of the tune yet where you start fiddling with things to get more power...still a lot of things to get through before that. I will say that his scans are getting better and better each time I see them though. For a tuning newbie he's moving along nicely.

Just to put it out there for those unfamiliar with tuning, the factory AFR settings are very lean (12.4:1 on most I've seen). Fine for the stock pulley, but it's no wonder KR shows up as soon as you pulley down. Also, the fact the Ken's O2s went down to 900mV could be seen as a good thing as that's what they should at with (unknown to me previously) a 12:1 AFR. It means that the tune is dialed in to the point where computer is no longer second guessing what the various tables tell it to do...a double edged sword in tuning as you don't want it to second guess anything if you know what you're doing and the car is set up right, but if you screwed up somewhere it can also save your motor.

X 2 Right now, my only concern is KR elimination. I do not want to see any KR. I'm not concerned about hp as much as I am about KR. With everyone's help and advice, I'm sure we'll get there soon. Thanks for the support guys!

EDIT: After writing the new .bin to the PCM and resetting the trim, last night I took the car to the store (ten minutes each way). She ran great! Still saw some KR in the same range but in only 4 or 5 cells and the max KR was 2 (mostly 1s). O2s were at or above 930 in the 140 Kpa column.

Could the cause of his lean condition and high KR be more of a mechanical problem? I got to thinking it might be leaky injector o-rings, but by page 10 I'm sure this was looked into.

I'll start posting my findings as well when I get my HPTuner later this week.

Allmachtige wrote:Could the cause of his lean condition and high KR be more of a mechanical problem? I got to thinking it might be leaky injector o-rings, but by page 10 I'm sure this was looked into.

All inj. o-rings were replaced. (Page 4)

It could still be a mechanical problem, though the 12:1 AFR wasn't helping anything. After the fuel trims are completely relearned we'll have a better idea.

Ken, glad to see the O2s are back where they should be and that the KR isn't too high anymore, 1-2 degrees is fairly normal.
Edit: Have you had time to take a look at the plugs yet?

Guys, would you prefer I make a new post or continue on this one once I start reporting HPTuner results/trials?

We could keep this thread going and make it the longest one on Pontiac Bonneville Club by far, but I think a new thread dedicated to just tuning would be good. The last few pages of this thread could almost be split into it's own topic as it stands now.

99ssei you haven't gotten into MAF tuning yet have you? I'm reading this guide http://www.hollandms.com/newbie/tuning_new.htm and I'm either really tired or reading too fast because he seems to be pulling numbers out of no where.

But if you haven't reviewed this section yet no need to discuss it at this time.