Well getting the VE table to be smooth has been a pain in the A$$.

I have.....
- the PO101,102, and 103 set to no MIL
- MAF fail freq. set to 0

Linear injector flow rate for 60lbs

-120 6.10999
-114 6.17505
-108 6.23901
-101 6.31396
-95 6.37695
-89 6.43896
-83 6.50098
-76 6.57202
-70 6.63306
-64 6.69299
-58 6.75195
-51 6.82104
-45 6.88000
-39 6.93799
-33 6.99500
-26 7.06104
-20 7.11804
-14 7.17395
-8 7.22900
-1 7.29395
5 7.34802
11 7.40295
18 7.46497
24 7.51904
307.57202
367.62402
43 7.68506
49 7.73706
55 7.78894
61 7.83997
68 7.89905
74 7.94995
80 7.99988

no flow rate modifiers

the High Octane Spark copied to Low Octance Spark

I have done 5 runs and on the first run I copied the AFR% and paste special to x% increase and then run 2 to 5 I copied and pasted special x% - half.

My end result made the idle to surge and my AFR% is leveled off to being all on average to be lean 2 to 4% error.

I copied over the 800RPM #'s I had to at the start of my tune of the VE Table and that took away the idle surge.

LTFT's was reset each time and I sometimes turn off LTFT's via the HP Scanner.


WHat did I do wrong? any tips?
Did I do anthing right? thanks for your help!

 

Our PCM's dont use the VE Table. Only when the MAF fails.

 

LOL oh ok. well no offence but I have been looking at a lot tunes that have that all programmed and there are instructions on how to go about it. without doing daily driving is terrible. it needs to know what to add to the air to get the AFR and also the PE table is based on the VE table so a good VE table influences you total tune. MAF is Mass Air Flow. the PCM uses that to determine air flow and then checks the tables (VE and the PE table if in Power Enrichment mode) but either way if you dont feel that VE is important then that is okay and I will wait till someone else can help me figure this out, thanks.

anyone else agree that I am wasting my time on the VE table?

anybody else that is using hptuners please help?

Well that was a brilliant post. guess it is far to boring.

I think I found out the problem. AFR Guage related. sucks

 

no dirvability uses VE tables im sure, b/c i know it helped mine a alot

 

Ok this is unusual to me. Just to be sure of what were talking about. the table I am referring to is Primary VE which is Primary VE vs. RPM vs. MAP.

most people I know and have seen on HPT forum etc. all work with this table to get the 14.7 before doing timing and PE. your pe table is say 1.336 x the value on the VE table to go from a 14.7 commanded to what ever PE you wanted.

what do you guys do for tuning? what do you changed with HPTUNERS?

 

The only reason to tune VE is so that you dont get a p0068 code (map/maf correlation). This activates limp mode. Disabling p0068 disables cruise control on most cars. Basically follow the ve tuning help file in your hpt help folder. I have only done it using a wideband so I have no experience just using fuel trims.

Dan

 

it took me 8 hours to get the VE perfect, than i decided to screw with timing and i blew my motor up

 

my problem seems to be the AFR Guauge. need correction calculation.

 

This might sound a bit obvious, but are you in open loop when you're wideband tuning, or are you using trims to tune?

 

i think he is in closed loop. using the trims.

 

should I force open loop? would that be easier?

 

PE table is what you want to change you AFR @ WOT.

 

Well, ya got me confused. I thought at first you were using trims to find afr error but you mentioned about an afr gauge being off.

If you are using trims and not using a wideband to calculate AFR error, you will not be able to dial anything in while in power enrichment mode for the most part and your VE table will never be 100% correct, especially for the upper half.

If you are using a wideband to find AFR error you have to be in open loop. If you are in closed loop trying to determine AFR error, it isn't going to happen as the car is constantly trimming itself to 14.7 until PE.

Also, as previously mentioned, don't stress too much over VE. Its only used as a backup for MAF failure.

Whoa, airflow needs to be calibrated BEFORE fueling adders. Hes talking about the VE airflow table.

 

Sorry to confuse you. let me clear it up.

I have a AUtometer AFR wideband. I am a beginner tuner. I am trying to get the VE Table right for my injectors. I dont want to take someone elses work and apply it to mine.

Fair enough if the VE table is back up that is fine. but is should be there right. I want to do it right.

SO I am tuning with % error AFR to commanded.
see below for flow rate table and other setup.

now I want to get a good VE table then work on pe as long as the timing is safe. I think I am missing just a few steps to do this right. your tips will be appreciated.

so here are my issues.

1. AFR actual being read correctly by HPTUners.
2. VE programming (I need open Loop? and how r where do I find info)
3. ensure timing does not cause excessive knock.
4. tune for PE.
5. tune maf % error. Tune beyond PCM capabilities regarding MAF (HPTUners has a ceiling).
6. You will likely add to my list in learning how to tune. thanks.

 

Of course, But I spent about 10 hours perfecting my VE table with no changes in AFR then I had to go to the PE table to get any changes. Took me a little while to figure out why it wasn't working.

 

If you did not fail the maf, and set up so LTFT's are not functioning then yeah changes made will be adjusted for. that is what the PCM does.

If the maf is relied on only is that not a recipe for disaster then. if it does fail and unaware, then your AFR is screwed. I dont plan on keeping my AFR in all the time to monitor it as I am not the only driver of the car. put the tools in the hands of the inexperienced and they dont know there is a problem or dont watch for the problem. then BOOM cause they ran lean. this is part of the definition of streetable to me. streetable means that anyone can drive it on the street without special instruction other than avoid curbs and watch your right foot....LOL at least that is my goal. I have a tune that works for me but I am achieving a good all around tune. I will get there but I have to learn how to use HPT first. so with that in mind....

assume my AFR% error is correct. How do I set up my tune so I can produce a good VE TABLE?

 

1. Setup an EIO PID for your wideband. The Autometer wideband in your sig should be set to (volts /.6666) + 10 under a custom PID. (assuming you have the pro version of HPTuners)
2. Use the wideband to compare afr error %. It must be in open loop or your error will always be +-5% as no matter what values the VE is calibrated to, the car will trim. Open loop allows you to compare the VE cal to actual AFR. Set ALL closed loop parameters to max values and log the status bit for closed loop in the scanner to make sure you are in open loop.
3. I've had a lot of luck using a GM Stage 2 timing map while tuning. You should be able to download it in the HPTuner's repository.
4. After setting MAF and VE, assuming all other adders have been eliminated, you should be able to set PE to where ever you want as it should repond as well as you have your MAF calibrated.
5. Same deal as VE. Force open loop and tune AFR error %. HPT really doesn't have much of a MAF limit for us, at least we should never see it. Our MAF is accurate to about 12,000hz and if you would happen to exceed that, you could change to a different MAF. VE however does have a limit of 215kpa thats hardcoded into the PCM, but you could run a "fake 3/4 bar tune" if you wanted to get around this if you would ever HAVE to run in speed density mode all the time (turbo swap or such).
6. There are a lot of good resources on the hptuners forums. However don't forget EVERY PCM is different as well as every tuner. What may work for one guy may not be true for your application.

 

thanks witt!! I will TRY IT.

yeah I have the pro. and set up the PID for my Wideband and AFR% error. A friend with wideband helped me out. it is just hard for us to get together to work on it. we still plan to work together, although he is breaking away to go TUrbo. that will be a very interesting project.

 

Okay huge help. I finally had a chance to try it. but this is what I found. in open loop everything is like close to 11 AFR. SO I tried to tune it back to 14.7. had some success but as I worked up to being at the magic number some fields went lean. really lean. not sure why. I was doing corrections as per AFR error (commanded vs WBo2), which is now corrected AFR WB02 to HPT.

SO the friend of mine who is no in Germany (and reads this thread and is a member of the forum) on a trip tells me to tune to the 11 and just get it to be linear. Let LFT's deal with it after. This makes sense to me as we discussed it. when in PE mode the PCM goes to open loop so if it is linear and works of current fuel trims it will provide the correct PE. the open loop is important only for operation in open loop. if it is linear and rich that is safe for most conditions. MAF and LTFT's will have an easy time working with a linear Open loop table that is linear as well.

so the plan is this

get VE table linear at 11 AFR in open loop then drive it with closed loop. then tune the PE table after the LTFT and STFT's figure out the best level for 14.7.

what about MAF% error. do I bother?

 

MAF is the most important part of the formula next to PE. The car primarily meters air using the MAF, therefor if your MAF is off by a certian percent, the commanded air/fuel will be off the same amount. This in turn will affect PE and any other adders in play and even spark as we have a spark adder table that adjusts spark based on commanded eq. ratio.

Your VE tuning problems sounds more like incorrect fueling values, namely minimum pulse width and voltage offset vs. vacuum. If you tune it to be too far off and depend on trims to bring them back you may set yourself up for limp mode as expected MAF vs. MAP may vary too greatly.

 

well since you put it that way.....LOL. now I have more research to do. every tune I have seen with 60's have not messed with the tables you speak of. Now dont take that as if I believe we shouldnt be tuning from the stand point you suggest, I just have not seen any tune doing it. the other problem we have is with 60lbs injectors the injector flow rate is capped at 8.00. how do you work with this? make it linear or start with actual values and when you get to 8.000 at -45 manifold vacuum just put in 8.00 values for the rest of the table? Or should it be done as I did by keeping it linear? do you have any tips on tuning or links for info tune the minimum pulse width vs voltage offset vs. vacuum?

SOmetimes I wish 45lbs injectors were enough...LOL? I am appreciating your help!

 

Well I decided to go linear. it is not that far off from what is it supposed to be. only 19.9%. to offset this I used the Flowrate modifier vs. volts and set it up to be 1.199 for all voltage. now it will increase all injector flow rates up to what it should be.

Now tuning VE. - going out and tune it to 14.7 across the board and saving this table. as weather changes (getting colder) I will verify that it is safe.

Once I have this completed I will look forward to correcting MAF vs. %error AFR.

Still waiting for any tips on ....
- minimum pulse width - currently running GM Values
- offset vs. volts vs. Vac - currently running with GMS2 values.

have not found much info on the above so any help is appreciated. thanks.