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I'am using the $0D ECM Definition File . Has anyone used this feature and can give me the heads up as what to expect . I no the fuel for sure just not sure how it is gonna effect other area's ?
Good info in the linked thread, worth reading it and the pdf's.
To add to it, at 0 volts in the offset & multiplier tables the compensation should be 0. This is to cover the event of the fuel pump voltage to the ECM going to 0, or if that ADC channel starts reporting 0 volts for some reason.
This can happen from a broken wire, bad pin at the ECM and so on.
To help determine the injector compensation values, disconnect the alternator, start a data log, start the engine and drive around for a while.
I was kinda getting the itch to do some tuning since the weather is getting alittle nicer around here . Yep i will do alittle reading first then do the driving .Thanks
That was some interesting reading and i believe i have the injector constants at low to mid RPM close but not perfect . When the topic got on the stumble that is very true but their was also a mention of bias number should match the Injector constant ? I do not no what that means can some one explain . I do have another question if my constants are set exactly what they are supposed to be like fuel injector constant , cylinder volume constant along with fuel pressure . Is their anyway i can change a table value so i can change the pulse width at the higher RPM's , basically what i'am trying to say is i need more fuel and i do not want to fudge the injector and cylinder constants and injector offset pw vs battery to get their.
To get more fuel, you need to adjust the VE tables, unless your injectors are going static. The base VE (volumetric efficiency) tables are used in deriving the airmass in the cylinder, and the required injector PW (fuel mass that needs to be injected). It sounds like the actual engine VE at higher RPMs is greater than whats in the stock VE table, causing lean-out. If your fuzzy about these concepts and how the fueling is handled in general, you may want to browse the stickies here on speed density tuning before diving in.
I have been doing alot of reading and something is not just right on my end . I tried everything well maybe not but the usual anyways . Seems like i can't explain properly what i'am trying to say so i''ll try again . Okay my constants for my set up are spot on along with fuel pressure . Injector offset pw vs battery is the best i can do right now as i lose my VE table on the higher RPM's so i compensated alot in the higher VDC maxed out . I have flow matched injectors which flow 26lb's @ 43.5 PSI . Idle all the way to 4000 RPM @ 100 MAP no problem at all BUT that is where i lose it i max out my VE table from their on up . My injectors are not even close to going static so i must be missing a table some where . That is why i wanted to alter my BPW multiplier vs. battery so i can put my injector offset pw vs battery to the mid range instead of maxing it out and set it up properly . Maybe i'am just being to picky and don't won't to fudge numbers to make things run . I have read all the sticky's and then some but not helping out on my end and Dimented your right on being fuzzy on the concepts i'am past the usuall set up's i think . I have a conversion from TBI to MPFI so i think that is why i have to alter a few more tables then usuall . I tell you this is not easy to figure out and not screw up my motor in the mean time .
I'm not real up to speed on the $Od but I see a table called
"WOT AFR vs RPM"
You may want to take a look at it.
there are two tables that use TPS% to control when WOT is indicated.
HTH
I have a LM1 hooked up and at WOT i'am 12.4 to 12.5 AFR clean across the table ,ya i looked at those tables already and got them set . Thats what is funny now that you brought it up it jogged my memory at WOT no problem but at the higher RPM's i got problem ?
Sorry, don't know what happened to the first link, was working fine.
Quote:
Originally Posted by 95 4x4
i lose my VE table on the higher RPM's so i compensated alot in the higher VDC maxed out ..
Not sure what you mean here, are you saying that in the "Injector Offset vs. Battery Voltage" table you maxed out the settings??
Quote:
Originally Posted by 95 4x4
I have flow matched injectors which flow 26lb's @ 43.5 PSI . Idle all the way to 4000 RPM @ 100 MAP no problem at all BUT that is where i lose it i max out my VE table from their on up . My injectors are not even close to going static so i must be missing a table some where . That is why i wanted to alter my BPW multiplier vs. battery so i can put my injector offset pw vs battery to the mid range instead of maxing it out and set it up properly ..
Ok, maybe I'm understanding a little better now. What your describing is what I was experiencing before getting the correct "Injector Offset vs. Battery Voltage" settings. But your missing the point of the "Injector Offset vs. Battery Voltage" table. It's only purpose is to make allowances for the electrical and mechanical abilities of the injectors being used at the varying voltage levels from the charging system. It can not be used to add or remove fuel. If fuel is added or removed it's indirectly not directly. The only way to set this properly is to have the injectors tested or find a published table for the injectors your using. In other words, the "Injector Offset vs. Battery Voltage" table must match the electrical and mechanical abilities of your injectors.
Quote:
Originally Posted by 95 4x4
Maybe i'am just being to picky and don't won't to fudge numbers to make things run. I have read all the sticky's and then some but not helping out on my end and Dimented your right on being fuzzy on the concepts i'am past the usuall set up's i think ..
Nothing wrong with wanting to do it right.
Quote:
Originally Posted by 95 4x4
I have a conversion from TBI to MPFI so i think that is why i have to alter a few more tables then usuall . I tell you this is not easy to figure out and not screw up my motor in the mean time .
I have flow matched injectors which flow 26lb's @ 43.5 PSI . Idle all the way to 4000 RPM @ 100 MAP no problem at all BUT that is where i lose it i max out my VE table from their on up .
This is indicative of the injectors not delivering their rated flowrate. Either due to a difference in firing stratagy causing a mismatch in what the flowrate should be set to, or the injectors are not being fired properly. The injector offset tables are mainly used for low pulsewidths. Ignore them for now, they aren't the cause of the problem. First, have you modded your injector drivers (bypass the sense resistors) to have them do saturated firings instead of peak and hold? P&H may cause issues with some saturated injectors if the drivers start modulating the current to the injectors.
Second, the injector constant in the PCM is set up with the assumption that there will be one injector firing per cylinder intake cycle. IOW, each cylinder will get ONE shot of fuel from the injector. In other firing stratagies, such as batch fire, the injectors typically fire together once per revolution. In this firing mode, each injector will fire two shots of fuel into the intake runner before the cylinder goes through an intake cycle. Its been a long time since I've looked over the firing stratagies in the PCM, but if I recall correctly, the injector constant may need to be changed to let the PCM know how much fuel needs to be metered. What do your VE tables look like?
Last edited by dimented24x7; 04-12-2009 at 04:13 AM.
Now i got it doing to much reading Injector Offset vs. Battery Voltage ya i was using this to get my extra fuel now i no BAD !! From 6.4 to zero the usec table is at 3890.99 maxed out . I have also compensated my cylinder volume also to get fuel to the VE table . My PCM is set up for PFI mode and to run in batch mode . My intake is a FIRST TPI set up . So i guess i will start my VE tables all over and set my constants correct and only increase the injector flow rate . I believe my Injector Offset vs. Battery Voltage is pretty close i have since alterd it during the post . Here is a pic of my fuel table .
The VE table doesn't look all that bad IMO. Looks about the way mine used to look, except mine would start going out of range at 4000 instead of 4400.
My recommendations are:
1. If using a stock TPI injector:
a. Make sure it's a saturated injector not a peak and hold injector. The PFI mod only works for saturated injectors.
b. Use the stock injector offset table for that injector.
2. Set all constants where they are supposed to be.
3. Adjust VE table until correct.
4. If VE still goes out of range, adjust the PE AFR vs. RPM table until WBO2 reads the desired AFR at WOT. If you must fudge the numbers it would be better to only fudge where needed. If you fudge the injector constant you will change the entire tune.
Okay here is something else for you to think about as i don't understand it . With my LM1 my AFR is 12.4 to 12.5 at WOT so why at 4400 in the VE table i max out ? Right now i have the constant set right for the injector offset table and also the injector flow rate BUT my cylinder volume just to get where i'am at now i had to increase it 35 % . So that means i diffenately have to increase my injector flow rate , i no i will have to re-do the VE table and i'am pretty good at it LOL . I originally started out with everything set as it should be just seems i need the fuel on top end . How about this thought instead of increasing my injector flow rate why not lower it as it increases the PW ? I think i'am doing to much thinking about thinking my head is starting to hurt . I will do another data log run on the weekend .
Could not open file here is the error : error [C:\Documents and Settings\Owner\Desktop\Truck Files\Advanced $0D v125 xdf.zip]: missing 26 bytes in Zip file (attempting to process anyway)
No my XDF file does not contain PFI constant .
Could not open file here is the error : error [C:\Documents and Settings\Owner\Desktop\Truck Files\Advanced $0D v125 xdf.zip]: missing 26 bytes in Zip file (attempting to process anyway)
No my XDF file does not contain PFI constant .
Use FireFox to download zip's from TGO. IE is broken. Not sure why. I just downloaded the XDF and it unzipped OK.
Okay i did my driving around with alternator un-hooked and i feel the BPW vs battery is pretty close . I also had to re-do my VE table and well it is maxed out pretty early as shown with the attached table . I put every constant exactly as it should be and i still have no fuel any sugestions . I'am thinking of uping my ejector flow constant ?
Sounds like you on the right track now. Without having the injectors tested you probably done all you can do with the "injector offset table".
Quote:
Originally Posted by dimented24x7
This is indicative of the injectors not delivering their rated flowrate.
With my set up I had reached this conclusion. My advice is to only lower the injector constant slightly.
You say you have no fuel at the affected areas, what does the WBO2 say? Have you tried upping the "PE AFR vs. RPM" table yet?
Don't forget that at WOT (100MAP), your actually in open loop, but the PCM still has some ability to increase fuel if lean, but won't decrease fuel if rich.
Ya your right about the injectors all i no for sure is they flow 26.76 lbs/hr @ 43.5 psi and all flow matched . Yes the WB shows exactly the area's being lean/rich . I have tuned in my WOT to have a 12.4 AFR using the PE AFR vs RPM table . I will try to lower my injector constant if my thinking is correct it will increase the PW . One step at a time for sure and once i get the fuel set next will be the spark table . Is it true the Vortec heads like lots of timing ?
You've got the fuel at WOT, thats what's really important. I would just lower the injector constant a little, in my case my injectors were 29lbs/hr, I lowered it to 25lbs/hr and did the rest with the PE table. May not be a perfect solution, but as long as the engine is happy it's a workable solution.
When setting timing it's gonna be a back and forth kind of thing. Set fuel, adjust timing, set fuel, adjust timing. Might improve the VE table some.
Vortecs actually dont like much timing. 28-30 degrees total is all you need at WOT. At part throttle, 38 degrees or so is the max under light load. Reason being is the CC. The tighter chamber along with a spark plug tip closer to the center means for a faster burn.
Last edited by dimented24x7; 04-23-2009 at 01:14 AM.
dimented from what i now understand is the timing should be around 14 - 18 degree at idle then ramp up from their to 36 - 38 degree up to 4000 RPM then taper down to 30 degree at WOT . By chance would you have a graph pic as to what the shape would look like , i just need an example hard for me to picture the curve . Here is a graph of mine then according from what i just said my curve is alittle bit off.