new guy here look for some help

[kelly brooks]

I have a 96 tahoe with L31 motor that I just did a 0411 swap on. I just got my efilive V1 on Wed and been playing around looking at things but, not making any changes. I started doing the VE tables by following the instructions.

My biggest issue is that it starts pinging or knocking at about 4000 rpm until it shifts. I logged it and the only thing I notice is my afr drops from 14.68 to 12.12 when the knocking starts.

so I am assuming I need to add more fuel as its getting to lean but not sure if I should do it at the PE modifier vs rpm or some where else.

here is the log from my calc.ve log. it happens at frame 5280.

like I said I am green. very very green so any help is appreciated

[WeathermanShawn]

Hi Kelly:

Welcome to the forum.

Generally your log and CALC.VE look good. It does appear you are getting some KR when you are at a lower RPM and add some throttle, and a few occurrences at Higher Rpm and greater throttle.

It appears to be occurring when you engine is undergoing greater load. You are hitting 'PE Mode' and the additional fuel is helping you avoid even greater KR.

You simply need to lower the Spark in those cells (and surrounding) a good 3-5 degrees if possible. I noticed your IAT's were pretty high. Where are you located? Also have you kept 'Burst Knock" enabled? That might actually help you in this case.

It's all about the Spark. Try a higher Octane gas or just run off your Low-Octane Spark for a couple runs and see if that solves it.

Good luck..

[kelly brooks]

I live in gilbert, AZ

I dropped the spark by 10% in the rpm range of 4000 to 5200 and grams/cylinder .60 to .76.

so I am not running lean I am running rich but, its actually helping me

[WeathermanShawn]

Yes, rich not lean..which is good.

You might eventually want to get a wideband and log your actual AFR's. If you have the V2 it is pretty easy to set up a serial connection.

On the issue of knock and spark. There are over a dozen factors that contribute to knock (KR). Sometimes KR can be 'false', in that it can be mechanically related sounds that set of the KR detectors. Regardless, the quickest and easiest way to know is to lower your spark.

So, yes try the lower Spark values and see how that works. If it persists, there are other methods to address it.

Good luck..

[joecar]

Hi KB,

If you remove two pid channels (e.g. DYNCYLAIR_DMA) you will get your pid channel count down to 24, this will allow faster pid updating on your next log (will give you 10 Samples/second vs 5 Samples/second seen in your log).

On the PIDs tab, the Channels column shows how many channels each pid uses (most use 1, some use 2); at the the bottom of the PIDs tab you can see the pid channel count. 24 or less pid channels gives you the fastest rate for your PCM.

The faster sample rate will get you a better waveform for KR... if the KR waveform shows a sawtooth pattern the it is real knock; if KR has a flat top (even after the PCM pulls down timing) then it most likely is mechancial noise (valvetrain maybe)... see what Shawn said above.

Can you audibly hear it knocking...?

[kelly brooks]

ya I just got my V1 4 days ago and just trying to figure everything out without blowing something up. LOL. Yes I can hear it but I think your right its valves because its flat top spike but, I have seen the saw tooth when I didn't hear it. Going to try and do a SD tune just need to do some reading on how to do it.

Thank you guys for the help so far it is appreciated

[kelly brooks]

ok I been looking at widebands. anyone recommend one over the other for use on a V1? Can I remove one of my stock O2's or do i have to weld in the new bung

[mr.prick]

Wideband Controller Poll (http://forum.efilive.com/showthread.php?13361-Wideband-Controller-Poll&highlight=wideband+poll)

The ability to calibrate the sensor is the most important option.
The Innovate LC-1 (http://www.innovatemotorsports.com/products/lc1.php) or the Powerdex AFX (http://www.ngksparkplugs.com/products/performance/afx.asp) are two choices.
The MTX-L (http://www.innovatemotorsports.com/products/MTXL.php) also looks good.

[kelly brooks]

the mtx-L was one I was looking at. can I just remove one of my o2's or do I have to weld in a new bung?

[mr.prick]

You could but a dedicated bung for the WBO2 wont hurt anything.
Using the WBO2 to simulate an NBO2 seems to be hit or miss from what I have read.

[kelly brooks]

well the truck runs way better with the maf unplugged. been trying to do my ve calc but all the numbers are way lower then what is already in my ve table not sure what is going on with that.

[WeathermanShawn]

Kelly:

Not sure what you are doing here. The CALC.VE Table is for closed-loop MAF-enabled tunes.

Are you truing to do a SD Tune? Closed or Open-Loop?

If you want to do a SD Tune, unplugging the MAF is not the way to go. Look at the AUTOVE Tutorial concerning C2901-C2904. You still have them enabled in your Tune.

You can't do CALC.VE Table unless your MAF is enabled. But unless you specifically have a need for a SD Tune, it is really not necessary. If you are ditching the MAF, then CALC.VE Table will not really help you...

[kelly brooks]

well I first said I don't know what I am doing. LOL that makes more sense. I had unplugged it to see how it ran and it runs so much better so i guess I need to do the calc.ve and try and get my maf calibrated because it runs like poo with is plugged in compared to when its not

[WeathermanShawn]

Kelly:

No problem. It can all get very confusing.

I re-reviewed your Tune and Log. Even though unplugging the MAF is not first choice, it does appear that you successfully failed the MAF. So, what you were running was Speed-Density (SD) closed-loop. That is O.K. Your Trims were very similar to the first log (that is good).

So ironically you were indeed running off the VE Table you have in your Tune. If that VE Table was from your original CALC.VE Values, then that is even better news.

Your Spark defaulted to Low-Octane. Perhaps that is why it felt like it ran better?

Here is the bottom line. Are you keeping your MAF? If you want to bypass it and run SD Closed-Loop..it is good news..you already are. You just need to realize that without a COS, you will be running off one Spark Table..Low Octane.

[kelly brooks]

interesting. If its running of the ve table even with the maf plugged in why does it run like crap compared to it being unplugged.

[WeathermanShawn]

With the MAF plugged in, the majority of your Airflow and Trim calculations are indeed coming from the MAF. Some people don't like running off the MAF. The MAF frequency oscillates a lot, there is sometimes a restriction..etc. Some people just like the feel of SD and prefer it.

Personally I run MAF. I do clean the MAF sensor every other month and have familiarity tuning it. You always want your VE Table and MAF airflow calculations to be as accurate as possible. Remember, the CALC.VE Table Tutorial was designed simulating a total MAF Failure. It is possible to tune both, but in all honesty a SD closed-loop Tune can be just as accurate and reliable. A SD Closed-Loop Tune simply utilizes the Trims correction plotted against the VE Table. Its very simple and very clean to do.

Again, just remember you will lose some functionality with Spark and Misfire detection..unless you run a COS.

Good luck. We can help you out no matter which way you want to go.

[kelly brooks]

I will plug it in and keep working on my calc.ve. If I can get it to run as good with the maf plug in as it does with it unplugged I wouldn't care if its there or not. Time to go for a ride and do some logging. LOL

Thanks Weatherman. might go to cos but, not until I see if I can figure it out. Besides it kinda fun. By the time I get this all kinda figured out I can do my motor swap and be able to tune it correctly

[kelly brooks]

ok that seems better. I lowered c2907 to 400 vs 4000. ran another log. I lowered my ve table so I am sure what that means but, take a look and let me know if I did it right.

[WeathermanShawn]

As far as I can tell your CALC.VE Table Log and Tune look perfect.

All your trims are good and other than some minor smoothing on your VE Table, it looks good. You are still picking up some 'KR'..right off hand some of it looks 'false', but occasionally it has more of the sawtooth pattern evident of slight detonation. How we doing on that wideband?:).

Where is your MAF located in relationship to your air-box and intake? Just keeping your air filter and MAF clean help a lot. If you feel your MAF is a 'problem', just a slight change to C2901-C2904 will allow you to 'disable' the MAF, but keep the ability to log the MAF frequency. Just a thought.

Overall, looks very good..Congratulations..now just hit WOT with a wideband!

[kelly brooks]

whats the best way to smooth it out?

wideband will probably get ordered friday. (payday) Was looking at the autometer since I already have some in my truck but, then started looking at the MTX-L

Maf is located about 6" from the filter and about 18 to 20" from the throttle body

[WeathermanShawn]

I attached a sample VE Table from your latest Log & Tune. Here I manually smoothed it. I took out some spikes and dips, but tried to keep the general slope of your VE Table. Ideally your VE Table should follow the natural Torque curve of your engines output on a dyno.

The two additional screen-shots are your MAF curve and your VE Table plotted in g/s and portrayed two-dimensionally. (under Tune Tool Tab Edit-properties-Display in g/s). Again, ideally the g/s value should match your MAF airflow in g/s. Its kinda a brain twister to think of it that way, but that is why your truck will run differently MAF vs no-MAF. Ideally you want the airflow's to match perfectly..

Hope that helps..

[kelly brooks]

so my maf curve should look like my ve curve at gm/s. that helps now I just need to figure out how to do it. LOL

[WeathermanShawn]

Yes.

Primarily in the 'slope' of the curve. Ideally it should match airflow (g/s) from the lowest MAF Frequency you encounter to the highest.

If you know how to work an Excel program you can actually line up the axis's and graph the two. Not to over-complicate, but the VE Table (g/s) utilizes a charge temperature. If you use your log's average Dynamic Air Temperature that will get you close.

The MAF also uses CYLAIR and the VE Table DYNCYLAIR for its airflow calculations. You can easily plot those and compare. You might checkout Joecar's Tutorial Links in his signature. He explains all the differences in a very clear and concise manner.

The bottom line is the VE Table can be accurately calculated. A log utilizing a MAF Frequency allows you to do it. Smoothing the resultant calculated VE Table to match it to the MAF will make it even more accurate.

Good luck..

[joecar]

Follow link in my sig, see Summary Notes.

[kelly brooks]

good stuff. guess I got some reading to do.