new member, need big help

[Yetti]

Hello all,


This is my first post here. I'm a rookie. Be nice. Lol.
I came across this site by luck after Googling all weekend.
I have a 94 z28, that I'm trying to datalog with TP RT.

I'm spent 2 days trying to get the computer to connect.
With out the cable plugged into the car,I do the self test and she passed everytime.
I have the latency turned to 1 for the usb driver.

I also used winflash -with no problem. I was able to make a
Bin from the car


I tried 100 times. It connected once and I recorded for 3-4 min.
Anyone have any advice on this?
I would really appreciate the help..

[EagleMark]

I've never had to change a latency?

Try this adx in this thread, it has worked for everyone on all LT1 vehicles, some need to connect and fail, dis connect and connect to work. Have to have vehicle running to connect on LT1.
http://www.gearhead-efi.com/Fuel-Injection/showthread.php?335-16188051-and-16181333-PCM-Information-EE-EEB

[Yetti]

Holy shit Batman. It worked. I changed the latency back to 16.
I just tried it for 1 min. I'm on my lunch break. Will log tonight. Thank u for your help.

[Yetti]

hey i have another question. im keeping my maf sensor. do i change the maf caibration table to adjust the idle BLM ? if so how much.

i know the ve table is for speed density.

this is a 10 min log at idle, and some quick revs.
if its not too much, would u mind giving her a quick glance...

thanx

[EagleMark]

Well there's nothing that simple about tuning and it's more complicated with an LT1.

What is done to your engine and car? Then we will try and give an idea how to continue.

[Yetti]

Block decked and bored. 030
Heads milled - maybe. 010
New pistons and rods
Ported and polished heads
Hotcam with 1:6 rockers
Portmatched intake manifold
Headers, moroso cold air intake, electric waterpump
automatic - Trans, 2.73 gear

[Yetti]

I almost got the blm to 128 at idle

I set my idle spark to 28 degrees. Is that toooo much?

[EagleMark]

I don't recall the LT4 Hotcam needing that much? Back it down some and see if it's really needed. Always do testing warmed up CL. IIRC there is "Closed TPS Spark Advance Vs. RPM" for idle/closed TPS spark instead of main spark advance table.

Adding 150 RPM to idle is usually a good move!

If your close to 128 for idle in a LT1 then your good to go. Be lucky to get within 6-10 of 128 for right and left bank. Closed Loop BLM correct?

Work on the timing for idle first, split BLMs at idle can sometimes be brought together by throttle blade adjustment, go for a drive and then park in drive and look at BLM right and left, can open throttle blades a little and re test. There's also individual fuel trim at idle, if you have headers and a IR heat gun you can adjust fueling based on temp of header. Again totally warmed up, I've had consistency using middle cylinder temps as guideline, like 3-4.

When all that is best you can then work on MAF tables with BLMs. But the MAF table always has to be a smooth slope so it may take 6 cells to get one area of BLM under control and have to look at where you started and ended and smooth the transition or raise or lower entire table. No spikes or drops here. Smoooooooth!

Math for MAF is same as VE BLM/128 * VE or MAF. I've always done the VE in Speed Density first. VE table is used as a lookup or comparison for MAF, MAF is used alone at WOT high RPM. Just like newer OBDII systems. It will run without VE or without MAF, but the 2 do work together. I know the internet says VE is only for MAF failure on LT-1, some say I'll prove it and zero out VE table, well that's true, it will run VE or MAF or the way it's designed and both. I have tuned VE and not touched MAF and straightened out BLMs... cams and idle are sometimes only time MAF needs adjustment.

[Yetti]

MARK, first and foremost- thank you for your help. i would of never made it this far. i appreciate it big time.

i have the car running in CL - -i have adjusted my blm's 6 times.(flashed the pcm 6 times) i have changed both o2 sensor.--


at idle- im only getting to 123-121 on blm
while driving im at 25 mph@1200 rpm - im at 108 on both blm

this is the way i change the table.

i take for instance blm is 121. i divide 121 by 128. that give me a decimal of .9453-

i then take that number and highlight all the boxes and multiply it by that number.


is that the right way?

and how do i correctly adjust spark timing?
i tried highlighting all boxes and multiply by 1.1

that increased all spark cells by 2-3..
is that the correct way?

[Yetti]

here is the log file from idling. and a few quick bleeps of the throttle.
DATA TRACING IS enable, for both ve tables and both spark tables.....

i still cant get the blm to 128--- everytime i subtract fuel ,--- it seems to lower the blm to the richer side...

let me know what u think... thanks ...

[EagleMark]

I looked at the log above and you need to get some more MAP going. Idle is 650 RPM and MAP is 55-60. Way to high. Add 150 RPM to idle and 3-5 degrees spark at idle and that should help there.

Your Z28 spark table should be fine other then idle for this cam.

Yes your doing the BLM math right but don't apply it to all cells, just the cells you got the BLM number from.

If you got idle BLMs to 123-121 your done, even if you could get them closer they would change with weather.

108 for driving is way rich, that is taking out max fuel. Are you doing this in MAF? All those tables have to be SMOOOOOTH... with the engine changes I would do the VE tables first in SD, then work the stock MAF tables.

[EagleMark]

here is the log file from idling. and a few quick bleeps of the throttle.
DATA TRACING IS enable, for both ve tables and both spark tables.....

i still cant get the blm to 128--- everytime i subtract fuel ,--- it seems to lower the blm to the richer side...

let me know what u think... thanks ...Ha! Looks like you raised idle RPM and added spark, way better. Idle is nice. :thumbsup:

Did you check the "Speed Density Mode (X= Enabled)" before adjusting VE tables? If not the MAF is adding fuel because you are removing VE...

IIRC I used to also disconnect MAF and turn off "MAF System Diagnostic, Error 48 " but I don't know that is necessary ?

[Yetti]

no i did not enable speed density mode- because of not having a wideband.
i will pick one up sometime this week.

how do i set up a tracer for MAF table? HERTZ AND GRAMS PER SEC? -- I DID THAT - AND THEY DONT MOVE

whats the math on adjusting the MAF table..

[EagleMark]

You can do SD without a WB, your still in Closed Loop and use BLM data like you have been.

Put all MAF tables back to stock and get the VE done first.

I've tried to do data tracing on MAF but does not have values needed for X and Y axis...