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Is there any hazard to copying a 93 VE table into a 95 PCM. Both are LT1's the 93 VE tables have a higher resolution. Would this cause a brick effect of the PCM I have copied and flashed the matching table parameters with no ill effects. I would like to copy over the whole table if it won't crash something. Figure the greater resolution can't hurt.
In this case it would... can't change a table that is already in the Mask. Unless you want to re-write the entire bin to make sure it works...Quote:
Originally Posted by beestoys
wouldn't need to rewrite a lot of code, but there is some degree of uncertainty when patching code that runs on a flash PROM.... make a code mistake with a MEMCAL based ECM and you get odd operating characteristics or an engine that doesn't even start. oh well, try again, no harm done other than some damaged pride unless you REALLY screw something up.
do it with a flash unit and you may brick it, requiring you to pull the flash PROMs from the board, burn them manually and re-connect them, or just replace the PCM entirely and try not to make the same mistake.
for this reason, i've patched the P66 V6 code as little as possible and with a lot more prior testing since i don't have a burner that will work with these PROMs yet. i also don't look forward to removing the PROM from the board and soldering a socket down in its place. what would be neat...... is if a hot-swapping program would be possible to impliment for a case like this. if there was a PROM that was modified and caused a brick event, pull it, insert another with some special code on it that would be copied to RAM upon boot, pull that PROM, insert the bad one and then flash a known good BIN into it using no external burner. i THINK this is possible to do, but i'm not 100% on that.
Thanks EagleQuote:
Originally Posted by EagleMark
Has a feeling that might be the case so I only copied over the rows that matched. Still trying to get this over rich thing sorted. it's fat all across the board so thinking I either have a constant I haven't hit right yet or my 02's are toasted. Got the pieces to put in the wideband to verify just need to drop the headers and install the 02 socket's. Plan to order the Earl's pressure seal inserts once I figure out what's in there.
Another question pertaining to VE tables I see a VE trim enable with Scan9495 going active and inactive. Could someone explain what the function of this is?
I've never used Scan9495. Got everything I need in the TP ADX... as far as VE Trim enable it sounds like that means Closed Loop is on?
VE Learn would be my guess. Have seen similar PIDs when using Snap-ON Modis.
EagleQuote:
Originally Posted by brian617
Yes it is in closed loop.
brian
I be that's it I know the system is trying to pull out fuel. I am running 108 and the INT is hovering around the same 108 to 117 at the most. I know if I rest it with Scan9495 back to 128 it will stay that way for about 5 seconds then pull back to the 108. when it's at the 128 it's very happy. you can hear it dropping then compensate as it's pulling back down to 108. I'll do some more research in TP and see if there a corresponding flag or indicator in there.
I am now thinking I may go pick up an 02 sensor and drop it one side and see how it reacts. Because they are all getting pulled to 108 even during normal runs. I ran this thing for a quite a while with the speed sensor side disabled unawares to the effect it has on the fueling map. Trying to deduce without spending money until payday and the tinker gremlin in me. Can't leave well enough alone especially if I know somethings amiss.
no speed sensor on EE wont really screw your fueling up that badly, you just dont have a nice grid of BLM cells. it will still trim, just wont learn from its mistakes, so transitional fueling can be worse (it has to re-learn fueling all the time)
it's very common for closed loop to pull way too much fuel at low rpm on a modified lt1 because of corrupted o2 readings at low airflows. use your wideband to confirm that. if the trims are correct, when it's settling on 108 trims, your wideband should flutter around 14-15:1. if it's pulling too much, it'll be at least 15:1 all the time, or worse.
but if it's hitting 108 l-term trims with a stock-ish cam and exhaust and a stock-ish tune, there is something wrong. if the readings are legit, and those trims do produce a mean afr of 14.5-14.9 kinda thing, that probably means your ecm is out on its initial calculation by quite a bit. mechanical issue or botched constant, or something.
lets start here, what kind of modifications have been made to this engine, and what changes have you made to your bin so far? what bin did you start with? running SD or MAF right now?
Ok here is the breakdown to get started with.Quote:
Originally Posted by steveo
This LT1 is a 93 Camaro SS transplant. It now resides in a 72 Elcamino. The harness conversion on the first iteration was done by Zac at Speed Scene Wiring the newest iteration is upgrading to a 95 ECM harness again built by ZAC. It now runs the MAF and has sequential fire fuel injection. It has a Bailey LTCC coil conversion in it running NGK V power 55's gapped at .050. The intake has been port matched to a BBK 1000 CFM throttle body. It has the Cold Air Intake from the SS. Exhaust is Headman Elite shorty headers with 3 inch collectors. They dump into a TA performance 3 inch full dual system mandrel bent to the rear bumper. There is a 2.5 inch crossover and a pair of Flowmaster Delta Force 2 chamber mufflers. Drive Line is a 93 T56 6 speed.
I have reset the injector flow constants to match the 93 factory injectors installed. I have tried to use 93 low VE tables grafted onto the 95 tables to see if it helped the idle BLM's, no joy I also realized afterward the files were from a 5 liter not a 5.7 (they didn't help anyway but then I was only checking idle running so it may have not shown up then). The VSS input was not hooked up for almost a year but the truck wasn't driven except on an occasional weekend. There was a 6 month stint when my youngest used it to get back and forth to MMI. Other than that it's a stock 95 bin in there with only that one change. (injector constant)
I have wide band that will be going in hopefully this week. That way I have a reference to see if the factory 02's are shot. (they were replaced when I changed out to the 95 ECM) had to different sensors and wiring.
I also plan to make some more log runs now that I have some guidance on how to make a more accurate run. that way I can see if my changes I make in the future are helping.
Any suggestions or help in the meantime are very greatly appreciated.
the VE tables on your car will make a negligable difference with the MAF running. i have a suspicion they are used for some type of fueling calculation, but having an inaccurate VE table wont affect very much either way.
you need to be scaling other things. are the trims that far off across the board, or just at low rpm?
SteveoQuote:
Originally Posted by steveo
I am thinking across the board. When I did a couple of log runs into work running a mix of surface streets at 25 to 55 and then freeway at 70 to 75 they all seemed to be the same. Now granted those logs were made with nothing disabled. EGR (is now and permanently per your guidance) PE and DFCO were running factory setup. I'll make another set of runs with those disabled under a more controlled environment per suggested methods I read by Eaglemark. Then see how it comes out.
I agree with you I have a feeling I have a constant out somewhere I just have to figure it out.
One thing I did notice yesterday while adjusting the IAC's.
They had gone to zero I though it was the BBK throttle blades being open to far. So I hooked up a Scan tool and adjusted the counts by backing off the adjuster screw. I got the counts back up in the 50's with a TPS voltage of .047. I then found out I had a vacuum line pulled that feeds my heater control circuit. Now the interesting thing I found was that the BLM's were up around 115 and 117. I hooked the line back up and they tanked to 108. I readjusted the IAC to mid 50's again with a TPI of .49. They are staying at 108 with the INT's at around the same maybe going to 117 but never higher. I know it's rich because every time I try to restart it I am very rich the truck will fire after a bit of cranking then it has to clear out.
So again I am figuring a constant is out that is why I have asked for a 93 5.7 M6 bin to look at tables and setting and maybe find something out there.
if it's affecting startup too, damn.
at this point, if you're confident that there isn't some kind of mechanical or sensor problem (which i doubt) just crank your injector constant till your BLMs are even, and go from there. try *1.05 or something to start with and see what happens.
i can tell you though, dont go too far.
from the ol' butt dyno and hundreds of flashes, having your trims reading a bit rich (say 118-120 kinda thing) is not a bad thing, and drivability seems better.
there's no shame in tuning it a tiny bit rich and letting the int/blm system lean it out for you..
keep this in mind:
24.912 injector constant on an fbody
24.873 injector constant on a 'vette
128 BLM keep-alive on an f-body
120 BLM keep-alive on a 'vette
same injectors. vette runs better. set just a hair richer on injector constant, and on an ecm reload, BLMs start at 120 by default instead of 128...
Ok just did a idle run logging from 106 F all the way to clutch fan engagement and resulted pull back down to 180. The IAC stayed pretty much at mid to high 60's and locked at 108 with the INT hovering around 110 for both sides.
Then backed her out and made a neighborhood loop. It consists of city streets at 45 mainly. With a Interstate shot of about 5 miles at 70 to 75. What I have noticed in the history tables is that it will hit the cell at 128 (so that tells me the constants there are right) I think? but within a second or less it will pull it out to 108 again. The history tables are pretty much identical for right and left (within 1 count). The range in the history spans from 20 to 60 on the MAP kpa and the RPM rang is from 600 to 4500. So I am inclined to think there is a constant wacked or the 02's are cooked. Anyone have insight to cooked 02's acting this way? It's running great I mean it pulls hard, without even hammering it I can feel it, but I know it's fat I can smell it.
One other thing I did and IR on the primaries and for the most part they are around 350 one is 270 and a couple are 400 so I may have a fueling issue. I have done a injector leak test using a remote switch to run the pump and scoped each port with a fiber camera and didn't see anything leaking.
could try some fresh o2 sensors to see what happens, they're pretty tempermental, but i think something else is going on.
what's your injector constant set to right now?
It's 23.594. We had to recalculate because of the fact that the 93 used 22# injectors instead of 24 the 95 ECM was spec'd to. I also am running a higher rail pressure do to a changed fuel pump and dedicated wiring harness. The result was a 50# rail pressure. So per a math formula of 50/43.5= this value is square rooted and then multiplied by 22 which gave me the resulting 23.586 hmmm that's not exactly the same. I'll load in the new value but thinking that small amount shouldn't make that much of a difference should it?Quote:
Originally Posted by steveo
Ok just tried to change it looks like the number there is the closest the hex can create so hence the differences.
woah woah wait what?
50psi from a fuel pump and relay?
i dont think so.
43.5psi should be max for a properly working LT1 regulator. doesn't matter how hard your pump is throwing fuel at it. 50psi is WAY out to lunch
what's up with that?
this is all weird stuff regardless, if you overshot the injector constant, it should be lean, not rich.
Ok a little clarification the math is done with a max value possible. The 50#'s is with the regulator unplugged from the vacuum port. Running pressure at idle plugged inot the vacuum port and warmed up is 44#'s.Quote:
Originally Posted by steveo
with a stock regulator that's way too high for an lt1, i dont care how much your pump is flowing or how much voltage you feed it; unless i'm way off base and the '93 regulator is higher pressure than the later one?
is it possible your fuel pressure gauge is screwed?
but that's weirder still, as your fuel pressure being ~22.something for normal pressure would increase your pulsewidth calc and your trims would be even further down?
I'm with steveo, if you changed the pump and wiring and the pressure went up the only way that should happen is if your pump is over-flowing what the regulator and return line can dump back to the tank. If that is the case, the pressure won't be stable as the fuel use requirements change.
You know got to thinking about this this morning and I will look into the return line. This didn't start happening till after I changed out the pump. Hard start and all is new I am thinking Like you both are that it's a mechanical issue.Quote:
Originally Posted by lionelhutz
I am going to check the return line pressure I have a feeling I am either backing up there or I could have a ruptured Regulator diaphragm and I haven't seen it yet. I'll drop a piece of clear vacuum line in there and light the truck off and see if there is fuel in it. (This was the only way we discovered it on the 2 91 Firebirds with 3.1 V6's we also own.
I'll let you know what I find.
Ok math should be 50 divided by 43.5 the resultant is squared then multiplied by 22 right?Quote:
Originally Posted by steveo
Update
found my other fuel pressure gauge older Auto meter. The Craftsman I have is designed for shrader valve hookups. The gauge is good just a pain to graft into the return side the Auto meter should be easier. Also found out that the fuel filter I had installed in the feed line has developed a hair line crack. So now I am going to pick up a factory one and plug it in at the stock location back by the tank. I am really hoping to find out there is a restriction in the return line and that I can get it cleared. I used the factory supply line for my return when we did the instal an made up a new 1/2 supply to feed the pump. It was a pain forming all that up in one piece and getting it in there. I am not looking forward to it but if I have to I'll build another 1/2 for the return line. Hoping to be able to get at least get it checked between the misses birthday celebration my son's replacement cat install on Saturday and the races on Sunday.
Ok just did the check and here is how it stands. I have a Walbro 255 intank pump with a racetronix power harness and relay to give the pump full system voltage.
Supply at idle 44#
Return at idle 3.5#
Vacuum line for pressure regulator pulled 50#
Return line for pressure regulator pulled 3#
Now I remember when I installed a Holley projection sytem in a Firebird anything under 5# on the return was not an issue.
Anyone have anything to the contrary from a manual or something that would say otherwise. There is going to be some return line pressure just because of the length of the return line and all.
Inputs or insights please
Note I also started a new thread along with this one for others at a later date to make it easier to find our results.