VE tuning with HPT Wideband and Narrowband how to

[JimMueller]

The last time I tried it, my controls seemed to have a time-out period, where they'd turn themselves back on even though the interface indicated they were still off. Maybe it's just in the '98s.

[WS6snake-eater]

AAArrrrrggghhhh! More frustration today. Okay, the last two days I went back to tuning via SD since I had a spare few minutes. I had all my cells between 12.8 and 13.2 and was ready to start my PE tuning, again. Had to fill up with gas and started to log only to watch my perfect SD tune drop a whole percent across the AFR table. I thought to myself, self, could you have forgotten to copy high octane to low octane. Nope, wasn't that. Sooooo, I started retuning, again and ran out of time and won't get back to it until after the New Year. I am really starting to question the accuracy of my WB. I have the LM-1 and I calibrate it in free air each day I use it to make sure it is right. So, anyone else have this happen with different gas. My last tank was chevron 91 on my way home from Famoso. This mornings gas was 91 from on base (military) station. Has anyone been able to consistently hold their AFR values from one day to the next. I realize weather and temp each day will change things but this is getting ridiculus. Off to study other things.

Jim K.

I have seen trends when filling up with gas also. It seems that every time I do, the Trims tend to go about 10% negative. I'm sure it has something to do with the evap and purge system, but I have never really figured it out. I usually just drive around for a day or so, then start logging again after a couple of days of driving. I have tried resetting the trims and so forth but it does not help. I don't know why they push themselves so far negative but they do. So as rule of thumb I don't tune my VE after filling up with gas. I will give it a couple of days worth of driving before I tune VE.

Matt

[cured5.7]

WS6snake-eater,,

Just a thaught, could it have something to do with new fuel being cooler and denser that comes out of the bowser, causing it to run richer?

Regards Mark :huh2:

[WS6snake-eater]

WS6snake-eater,,

Just a thaught, could it have something to do with new fuel being cooler and denser that comes out of the bowser, causing it to run richer?

Regards Mark :huh2:

I believe it has more to do with: airation of the fuel. Have you ever poured a glass of water into a bucket of water? It tends to airiate the water that is already in the bucket, thus oxygenating it. I believe that we might be seeing something similar to this while filling up our tanks. Eventually all of the extra "oxygen" is pushed to the top of the tank and ventalated out through the purge/evap system, but I'm not sure if that's exactly how it works. I am simply theorizing.

[cured5.7]

WS6

You would think that all those little air bubbles floating around in your tank would dissipate rather quickly once the tank was filled.

Hmmmm something to think about.......

Regards Mark

[arthansen]

I was looking at some of the VCM controls that we got with Ver 1.5. I was wondering something. If instead of going through all the table changes to command a 13.0 AFR, we could just set the AFR in the VCM controls to 13.0 and turn Closed loop and Fuel Trim Learn to "Off". Once you are done, turn them back to default (once you unplug, they return to default I think). Anybody have any input into this?

[Magic_Chicken]

I had that same idea about turning closed loop off instead of unplugging your MAF. I think it would probably work. Anyone else?

[Dragman]

I have seen trends when filling up with gas also. It seems that every time I do, the Trims tend to go about 10% negative. I'm sure it has something to do with the evap and purge system, but I have never really figured it out. I usually just drive around for a day or so, then start logging again after a couple of days of driving. I have tried resetting the trims and so forth but it does not help. I don't know why they push themselves so far negative but they do. So as rule of thumb I don't tune my VE after filling up with gas. I will give it a couple of days worth of driving before I tune VE.

Matt

I have filled mine up while doing my VE table but have not noticed any big changes!

[JimMueller]

*breaks out the shovel and digs out this corpse*

Well, I'm a bit tired of fighting with the SD tuning. Seems like there are always a few cells which don't want to stay in range, so I'll try it as-is. Restored my AIR & MAF functionality, reverted the tables, and left the P1514 tables stock until I see an error. I'm going to dump the tune in tonight and drive it for a few days before logging. I've been running this temp-SD tune for a month or two. I'm wondering how much the extra fuel has hurt sensors (not counting the one in my wallet!)? I do have new O2 sensors, but didn't want to put them in until this was finished.

Do I need to reset the LT's or anything else? I would still like an explanation on how to use the O2 Rich/Lean, Closed Loop Proportiojnal, etc tables...

[JimMueller]

First minor hurdle...

I set my enrichment to 1.16 (12.7 AFR). LM-1 showed normal closed loop operation, but the AFR histogram showed a steady 12.7 no matter which cell I was in. WTF? I must've changed something else in the calibration...

Hmm, no, can't find anything. Hmm, I think that's the value HPT reports when it doesn't detect the AFR device. Dang it, I just repaired that cable, too! OHHHH...

I bet I picked the wrong cell in the table. Sunnabeotch...yep. Switched from input 2 to input 1 and all is well at this time : I did reset the fuel trims, and they went to -7 after a brief period.

HPT needs something to pop-up saying, "Hey dumba55, pick the correct Input" ;D

[marc_w]

The last time I tried it, my controls seemed to have a time-out period, where they'd turn themselves back on even though the interface indicated they were still off. Maybe it's just in the '98s.

I found the same to be true for my '04 truck.

[marc_w]

I've been holding off on SD tuning my truck, because my IAT is in my MAF. I plan to run my MAF afterwards, and I don't particularily want to clip a wire in my harness to disable the MAF sensor.

I thought I recalled hearing that V1.6 would make SD tuning very very easy, with a parameter to shift between MAF and the VE table?

...or is that going to only be in the 2 bar(?) SD HPTuners software?

[BQuicksilver]

Along those same lines....

As a C5 guy, I also dont want to clip a MAF wire to tune unless I need to.

I see two options presented in this thread, but no real reports back.

Which is best for SD tuning?

1) Setting MAF Fail frequency to 0? Also, where do you find this setting?

2) Using the VCM controls to turn Fuel Trim learn and Closed loop off?

Also, has anyone been using the VCM controls to get the 13.0 AFR? Or is changing all points to 1.13 in the Open Loop F/A vs ECT vs MAP table the best method?

[Arron]

Setting MAF Fail frequency to 0 works for me , if you go to Edit / Engine Diagnostics / General in the editor MAF Fail frequency is first on the list.

[Arron]

Ken , Keith or Chris
was just wondering if the 02 switch points relate directly to ftc's. i.e if you are in ftc #2 this would be airflow mode 2 witch is 486 mv for my car.

If this is so then if i see my ltft's start to drift after i have my ve table dialed in(using openloop 13:1 and wideband) then if it is ftc 10 that i am getting ltft's that are out of the range that i want then the setting in airflow mode 10 in the 02 ritch/lean vs airflow would be the setting that i want to have a look at ??


Well after reading the thread below it looks like i was off on the wrong track with the question above .

[ixc]

There is a lot of good information in this thread, probably the most complete for SD tuning ive soon. Good work guys.

I do have one question though...I followed the steps listed for wideband tuning and set my MAF frequency to 0. When i uploaded the tune, the car wouldnt stay running. I would try to hold the revs up to see if it was the VE table but it would die there as well. Is there something I had missed?

Also, by changing the fuel multiplier, this sets the A/F to 13.0? you dont have to change it in the stoich A/F?

[corpsvette]

Welp, finally got to try out ver 1.6 using the SD method. I am impressed. I had my VE table dialed in no time to 13.0. One question I do have or more need reassurance concerning is the MAF Freq to zero (0). Are ya'll sure this disables the MAF. I usually unplug it but decided to try this method. Also, at one point I failed to turn on my WB and yet it was logging numbers anyway and not the usual 10.0 across the board either. Where was it getting those numbers. Finally, I looked at the AFR % error and the numbers are like 2, -1 etc but when I special paste it makes the right correction to the VE table. Is that like .01% and -.01%. It looks more like a difference from say 13.2 - 13.0. Hope to play with a few other things tomorrow. Have fun all.

Jim K.

[BQuicksilver]

Jim K (or anyone)

Did the car behave well after an nitial tune per the suggestions in this thread, or does it require a lot more work to get good street manners? I'm curious as to how complete the instructions in this thread are?

[tici]

I'm driving around with the fail MAF frequency set at 0 and at the beginning I saw an average LTFT of -10%, this with stock internals, 98 VE tables, 36 lbs bosch injectors and 60 psi fuel pressure instead of the stock 55 psi.

I probably made a mistake with the IFR tuning, this could explain the -10%.
The IFR should be ok now, but still I have rich (-5%) and lean (+2%) spots.
Low load is rich, high load lean.

Is it possible, that the original VE doesn't match the stock internals?
It's a 98 F body and it has the 97 Y body engine, maybe the tune of the first LS1 engines wasn't 100% perfect?

[corpsvette]

Bquicksilver,

The only time mine hesitated or stumbled was when I loaded the initial bin file. It took a few minutes of foot on the pedal to keep it running. Reminded me of warming up my 70 Dodge pickup w/ manual choke. After that, it ran fine but be reminded, I am totally stock. Bottom line, enough people have chimed in to make these instructions work well IMHO.

Tici,

I can't help you so maybe someone else can chime in.

Jim K.