idle afr question

[andysc3]

Truck is currently SD tuning the ve table. When I come to a stop the afr will go down to about 11.8 and within about 45 sec it will go up to 16.6. It will give me something like a 1.15 multiplier. Change the tune and it makes the idle go to 11.5 then goes up to 16.3. Also when I try to take back off the engine will bog down for about a sec then it will move. Any ideas? I will post the tune and scan in the morning.

[BLK02WS6]

After you post the tune and log, we will try to help you out...

[andysc3]

13147 scan
13148 tune

[BLK02WS6]

Do you have the MAF unplugged? It is still reporting... Also, you don't have it in open loop B4205...

Edit - where did you get that timing table from? that combined with B5908 can give you some pretty high timing...

One more thing - where did you get the injector table data? which injectors are they?

[joecar]

Something is wrong with either the tune or the wideband or both...

What FPR do you have (trucks usually have the rail mounted manifold-referenced FPR with return line)...?

What does rail pressure measure (with reference hose removed)...?

[andysc3]

Injectors are 42# marine 8.1l. Fpr is a non reference vett fuel filter. Constant 58# of fuel pressure. At wot I see 31* at the top of each gear. Maf is still plugged in. That's where the air sensor is.

[BLK02WS6]

That's a lot of timing - why so high? You need to pull the signal wire for the MAF - one of the tutorials (I believe virtual VE) shows how to do it with pictures - some of them don't fail completely and the wire has to be pulled. Did you get the injector data for those injectors from a reliable source? Some of the tables don't look right... Once you get it completely in OLSD, you will need to get some more logs - include IPW.

[andysc3]

Injectors data was from the previous tuner. I haven't touched it. I get the codes for the Maf when I put it to SD. It runs great when its using the Maf. Nothing else is changed. I'm going turbo in a few months and I'm going to run cos3 and be strait SD.

[joecar]

Yes, the MAF codes trigger the failover to SD (running from VE only).

[BLK02WS6]

In that case, would be best to go ahead and convert to COS3 now and run SD - then all you will have to do is add the 2bar sensor and tune for boost.

If you are getting the codes, it is in SD like Joe says above. Can you get a log with IBPW so we can see what the injectors are doing... I will try to find an 8.1 tune to see what the injector tables should be - I still think something is up there...

[andysc3]

The previous tuner was using the same type of injectors in his truck. Thats where he got the values

[andysc3]

13249
13250
There was a slight exhaust leak at the collector for the long tubes. Got that fixed. Updated the tune and got another log. It doesnt bog down anymore but when I stop it goes very rich and after a bit it goes back up to where it should be. Im thinking I may have to raise the desired idle to about 850. Would that help keep the idle timing more fluent? Will I have to redue the idle airflow? What pids do I need for that. Thanks.

[BLK02WS6]

I'll be honest with you - looking through your tune, I see so many tables that are out of whack - if I were tuning this, I would totally start over with a stock tune and retune it...

[andysc3]

Like what? How should it look? Driveability is good. It's just going rich when I come to a stop.

[BLK02WS6]

Injector tables - pulse width voltage adjustment, small pulse adjust, minimum pulse width and default minimum pulse width do no match tables for 8.1 injectors (don't know where you previous tuner came up with those)...
VE table - several places where cells are randomly high or low...
PE table - leaner in peak torque band (totally opposite of what it should be)...
Timing tables - too high in many places with adders still in place - large drops and rises (not smooth)...
Throttle cracker - this is probably contributing to your idle dropping so bad when you come to a stop...
MAF table is pretty lumpy...

I stopped there...

[slows10]

^^ Have you looked at a marine 8.1 tune? Thats where the injector values come from. If the ifr is different would the other injector tables differ as well?

[andysc3]

The injectors are the 8.1 marine 42#. The fpr is non referenced, so its constant 58#. I have a fuel pressure gauge installed and can verify that. The peaks in the ve table are pretty much out of range. I idle at around 50-55 kpa. The idle doesn't drop, afr does. Then after about 30seconds it raises back to 14.6 and stays pretty consistent.

[BLK02WS6]

Look at this screenshot of your log - when you come to a stop, idle drops to 300rpm! The MAP goes to 87kpa and proceeds to dump a whole shit load of fuel in there... takes a while to recover from that... stop the idle from dropping and you'll stop dumping the fuel in there...


As far as the injectors, I wasn't talking about flowrate being off... I didn't know they were marine injectors (don't have the tables for those)...

[BLK02WS6]

Have you checked for vacuum leaks? Also, does it have cats?

[andysc3]

There's no vac leaks. The exhaust leaks are now fixed. It has cats for now. Will be installing a ory pipe and a 4" duramax exhaust within the next month or so. I updated the tune alittle. Have idle set to 850, smoothed the ve and spark tables. I haven't had time to upload to tune to my truck. I might be able to do some logging this weekend. Thanks for the help. Also, for the throttle cracker, do I want to add to the numbers? And by how much?

[BLK02WS6]

The cats may be causing some of the issue with the wideband readings! Especially if they are older and may be clogging up - they will hold the exhaust back and the wideband sees it as rich... you will probably want to rework the tune after you get the ORY... you can also try to work the lower/mid VE ranges using the narrow bands and LTFTs...

With the throttle cracker, you want to add air to keep if from dying while coming to a stop - it is trial and error on how much - add a little at a time and try it. Keep the table smooth - no huge shelf from one MPH range to the next. No problem on the help.

[andysc3]

Yes, I bet the cats are most of my issues. lol
Got the updated tune loaded up and went for a short drive. The AFR is doing better but still has a few issues in some places. Whenever I get on the throttle the rpms drop. What would cause this. I will attach the tune and the log.

13295
13294

[BLK02WS6]

Try this one out... It's going lean when you take off, so I richened up the VE in that area and smoothed some other areas. Also, timing was taking a bad dive when you first take off and there was a dip in your timing table right there. Also, the idle timing was very high, so I lowered it a bit. When you come to a stop now, does it run good even when the AFR is going rich and then slowly leaning out? If so, don't worry about that - I think it is just the cats and will be remedied when you take them off...

[andysc3]

OK, Ill try that and get back to you. Thanks

[andysc3]

Here is a log of the updated tune. Idle is much better. and take off is a lot better.
thanks for all of the help.

13305

[BLK02WS6]

No problem! Still lean when you get in it harder - added some more fuel to the VE... pulled a little more idle timing out too... see how this works. I'm thinking things will be much easier to dial in when you go to the ORY...

[slows10]

Andysc3 what tuning method are you using? Are you setting up maps for the ve changes? Applying the ben? On your log I see you are logging iac steps. They seem to be pegged at 310 steps constantly. I assume you validated the pids? Is it just not enabled but selected on your pid list? Also Why are you using analog wideband? Are you using V1 flashscan?

[andysc3]

I followed the auto.ve tutorial the best I can. I usually use the pre-programmed pid list for the ve. It needs to hurry up and be winter here. It gets up into the 105-110*F during the day. I saw my AITs go to 145 driving in the city.
As for the ORY pipe, Im still undecided if Im going to put a Procharger D1-sc on it of a 76mm turbo and use my 4" dmax exhaust kit after the downpipe. Either way the cam would have to be changed. So they will cost about the same in the end.

[slows10]

On the logs you posted over the last few days saw that the IAC steps were pegged at 310 steps and did not move during the length of the log. Is your throttle body stock size?

[andysc3]

No, the stock was a dbw 78mm and I installed a polished ls2 90mm tb and the tbss/nnbs truck intake.

[slows10]

Yes Forgot the earlier ones came with both.

[andysc3]

yea, people on my other forum constantly ask me why I switched to a DBW TB on my 01 truck. But the Sierra C3 came standard with the 78mm DBW TB. Although through research I need the LS3 TB. It opens in the opposite direction and can increase throttle response and better low end torque.

[andysc3]

I ordered the Pacesetter ORY and I got some measurements from my Dmax exhaust. Im going to put my wideband on the drivers side turn like it is now unless yall think I shoud move it somewhere else. Here is what I have
http://i663.photobucket.com/albums/uu354/andysC3/IMAG0212.jpg
http://i663.photobucket.com/albums/uu354/andysC3/IMAG0213.jpg
http://i663.photobucket.com/albums/uu354/andysC3/IMAG0214.jpg
the measurements:
A-B= 16"
A-C=38"
A-D=49.5"
E-H=36"
F-G=30"
J-K=7"
J-L=32"
J-M=40"
A-M=127ish
The cutout is 10"
the 3-4 merge is 5.5"
I will have to cut about 1" off of A-B because of the flange.
The front pipe goes under the frame cross over. I would like to keep the exhaust as hidden as possible.

I have 4 options:
1: I can install everything like it that and run the 1 muffler.
2: try and fit a 14" body, 8" round, 20" overall magnaflow between the trans and tbar xmembers, there is just enough room, but am unsure if the front pipe will fit. I would have to cut it all the way to B.
3: I could buy about 4' of 4" tubing and run it strait like how smokeshow has it.
4: same thing with the 4" tubing and try and fit the smaller muffler in the same spot as earlier.

Any other options? What would yall do?

[andysc3]

Got the new exhaust on. Used 3 bolt flanges on the collectors. Everythings sealed. No leaks, and it still goes rich when I come to a stop. Will go to about 11.8-12.5 and slowly rise up to normal.

[joecar]

Can you post your current tune/log files.


Your intake manifold is not stock, so I'm wondering if transient fueling (dynamic port wall wetting/evaporation) is now different.

[andysc3]

I'll post the tune when I get off work. I sent my stock fuel rail to get modified to fit the nnbs intake. So I will have the stock fpr. And it only really goes rich when its not to full op temp. Once its to temp its not that bad.

[andysc3]

13425
I'll work on getting a log from cold start to full temp.

[slows10]

If you are going to run a sd tune, why not try a custom o/s?

[slows10]

At 176 temp you are telling it to get richer(13:1) on 60-90 kpa rows, on B3605. You have no 02 feedback, so if your ve table is off you are also going to run very rich or lean. Try enabling B4206. And log what the trims do.

[andysc3]

OK, Ill give that a try. I will be going with a COS3 shortly. But until then

[andysc3]

loaded up the new tune. Went for a drive. It was running lean. Updated the VE table with the map from the log. Went for another drive and it was a lot better. I guess I hit the yellow button and didnt record the second drive so I'll have to go for another drive later today.
Also, I ordered some Fast 65# injectors. Would it be ok to run them when I swap the factory fuel rail with FRP on. Current 42# injectors are at 63% idc at the shift points. Adding a Procharger D1-sc at about 11-12# in about 2 months.

[joecar]

Unrelated:

your B3616 PE Enable is too restrictive at 90% TP, you will get better throttle response if you make it easier to enable

(for example, take a look at B2616 in a 2002 F/Y-body file)

[andysc3]

How much? 85%? Lower?

[joecar]

F-body B3616 looks like this:

0 64
400 64
800 64
1200 64
1600 64
2000 64
2400 64
2800 64
3200 64
3600 60
4000 54
4400 34
4800 34
5200 34
5600 34
6000 34
6400 34
6800 34
7200 34

[andysc3]

Ok, Ill try something like that.
What about my injector question? Will the fast 65# injectors be "too much" for my current mods. The current 42# IDC is at 63% at WOT.
also, for the COS for the v1 i need to switch to personal to commercial. Is this what I need
http://www.efilive.com/index.php?page=shop.product_details&flypage=flypage_EFILive.tpl&product_id=54&category_id=8&option=com_virtuemart&Itemid=54
I have the serial # but where do I fine the Auth code?

[Tordne]

Please see this article (http://support.efilive.com/kb_article.php?ref=2143-YUOG-8049) for details on how to find your Serial Number and Auth Code.

[BLK02WS6]

You can run the bigger injectors until you put the blower on it - would be no different than driving around not in boost... Will give you time to get the idle and part throttle worked out before the blower...

[andysc3]

Ok, thank you. I'll get the cos3 started next weekend and swap the injectors when my fuel rail gets here.

[andysc3]

Started the COS3 swap.
Can someone sanity check my tune and the first log.
13476
13477

[BLK02WS6]

Its saying Boost VE is out of range, but it isn't... that's weird. Looks like you are on the right track though. Your not going rich when you come to a stop any more...

[andysc3]

Yea, It transitions very smoothly. Was even able to set the idle lower and you can really hear the cam now. Next issue is it goes very lean when I let off the throttle. Guessing its somewhat due to the lack of exhaust backpressure. I have noticed that it wants to buck when slowing down. DFCO is disabled. Could it be doing this because of the lean condition? Next is get the injectors installed and hope to have the Procharger installed next month.

[BLK02WS6]

Yes, it is probably doing it because it is lean - check your map and see what the VE needs to get it right in that area...

[andysc3]

The log is showing 1200-1600 rpm vs 30-35 KPA needs to be multiplied by about 1.25-1.3 but it create a rather large spike in the ve table . Ive been slowly increasing the effected cells and it seems to get somewhat better.

[BLK02WS6]

Thats the way to do it - also, smooth cells around the area that you working - you don't want large shelves or valleys...

[andysc3]

Thanks. I'll keep doing it that way until it clears up.

[joecar]

Started the COS3 swap.
Can someone sanity check my tune and the first log.
13476
13477


Its saying Boost VE is out of range, but it isn't... that's weird. Looks like you are on the right track though. Your not going rich when you come to a stop any more...



Out of Range calibration summary: 07:37:17 pm, Wednesday Aug 08, 2012

EFILive Custom Calibrations
{A0009} Boost VE Table, contained one or more out of range values when loaded.

It is OOR, but the tunetool displays the closest in-range value (i.e. either max or min)...

to fix it you have to do this trick:
- set the OOR cells to some in-range values excluding max and min;
- save file;
- exit tunetool;
- open tunetool and open file;
- if you want those cells to be max or min, then now set them as you wish;
- save file;

those OOR cells will now be in-range.

[joecar]

Started the COS3 swap.
Can someone sanity check my tune and the first log.
13476
13477With boost your PE should be richer than that...

something like EQR 1.24 (AFR 11.8)... you have PE set to EQR 1.155 (AFR 12.7) which is ok for NA but is lean for boost.

I don't remember: is your FPR manifold referenced (usually is with a truck)...?

If yes, then your IFR is wrong (it slopes).

I think you have too much spark timing for boost.

Your WOT downshift MPH have to be below the corresponding WOT upshift MPH.

[BLK02WS6]

He doesn't have the blower yet - was getting the COS in there in anticipation of a blower later on... His FPR is not manifold referenced.

When I opened it, I didn't think it was displaying min or max... and it didn't have the blue annotations on the cells... that's why I thought it was weird...

[joecar]

Ah, ok, I see (boost/FPR).


Hmmm, what V7 build version are you running, and what cell units are you displaying, Bret...?

[BLK02WS6]

Hmmm, what V7 build version are you running, and what cell units are you displaying, Bret...?

V7.5.7 (Build 180), I was displaying A0009 and the highest value in the table shows 497 in the 285 kpa column... not at the max...

[andysc3]

The blower has been on for almost a month now. Maxing the 65# injectors at 5300 rpm, ordered some 1000cc injectors from FIC. Boost AFR is right at 11.6-11.8, and timing is at 9* at 5200. Seen a max of 141 kpa at 5200 rpm. atmosphere is about 89-90 kpa here. should see about 160-170 kpa when the new injectors go in.
As for the FPR I was non referenced, but went back to the stock FPR when I installed the 65# injectors.