Tuning with GMPCM (answering questions)

[SappySE107]

BLM follows INT based on how far its off, and some other parameters. I can watch mine in idle, when it was off anyway, start at 128, quickly drop to 105 int, blm starts dropping like a brick for the BLM, 127 126 125 124...till the INT starts going back up closer to 128 again. Then the BLM stabalizes.

Where did you get the info that the int hits 80, then the blm goes down 1, and the int starts back over at 128?

[sil]

www.thirdgen.org is where i read it, ive been doing so much reading this past few hours trying to get a grasp on tuning and shit that my eyes are sore, and i wouldnt be able to remember where exactly i found that for the life of me, i think in efi performance tuning and its one of the top 5 posts there

[sil]

I was hoping to get questions so that I could answer them, as it seems that now I have to proof read what someone else has said. Id rather just ignore all that honestly and continue on my own thing, and from there let others critique it.

if your going to even bother posting "what you know" instead of sitting back and waiting for people to ask specific questions about specific code and specific this and that... the info you are going to aquire is going to be chunky and allmost usless when noobs are reading it.

might as well go all out and start with ..lets say DF code in gmpcm and do a walk through of what things should be looked to get the fired up for the first time, then scan and data log read and interperate .. what to look for, where to go to change .. ect.. get my drift?
i jsut think if your going to put any effort into making a nice write up on tuning your prolyl not going to want to leave holes in it... noob friendly is the way to go dude

ahhh i need to get away from the computer and have a beer
i cant find anything good for DF code anywhere ...its frustrating me lol
eventually i will peice it all together and make a "users guide" and have a list of what all the fuctions do and a short explanation of each... it hink that would be pretty cool, and deffinatly ORIGINAL

PS: sorry for hijacking your thread Lol

[SappySE107]

Yeah, ive done a lot of guides and walkthroughs...kinda got burned out a while back. I got no problems answering questions and such though. I just want to make sure the info on this site is accurate. I know A1 and DF pretty damn well though im sure someone out there has done more with it than I have.

As far as tuning goes, it really depends on what you are tuning and whats been done. I spent 6 months learning how to properly tune my old 3.1 that was modded. If you want to learn how to tune, use a stock car. If you are modded already and need to tune, then I pray you are using stock injectors. If not...well, your learning curve is sharp as hell.

[Mars]

your learning curve is sharp as hell.

This guy speaks the truth...

91 Cav 5 spd. running the TGP code with 30# injectors, and instead of a turbo , I have a supercharger... Holy learning curve.

But it keeps getting closer and closer to ideal. Just can't give up.

[TurboGTU]

I've used this as a guide..from DIY-EFI..from Bruce Plecan.

A suggestion is start at idle. For a SBC the initial timing for the distributor is 6 degrees before BTDC. How do you setup 6d without a timing light? On GM style distributor there is a set of little arrows inside the distributor. On a V-8, 8 on the reluctor, and 8 on the sensor ring. Just line the marks up and tighten the distributor clamp.

The engine fires when the arrows are ever so slightly past each other in the direction of rotation. The second you get to about 400rpm is when the engine starts running off your ecm control. Less than that and on a cold day the engine will windmill when it's cranking. Fill in the 400-800 RPM areas of the timing map with 16d (Table 1). Also, fill in the lower rpm VE tables (Table 3*mapvsrpm) with 30, and try to start the engine without grinding the starter too much. The engine will warm up enough to wake up the O2 sensor, look at the scanner, and see where the BL is, and IAC Counts. The IAC Counts are a vacuum leak. So they are critical to a decent idle.

Now you have some idea of where the mixture is, and what the Kpa is from reading the scan tool. From experience you can't run the same numbers everywhere at idle. On the high side of idle Kpa go richer, ie; with an engine that idles at 60 Kpa if it is 30 there, at 65-70 it would be 32, and at 50-55 28. Yes, the 30 is a lot but its easy to go lean, and clean up the idle, then having stall all the time, and having to wait for the prime shot to burn out.

Next, lean the VE values (Table 3) down till the O2 is swinging (value moving back and forth through .45 volts) , the IAC is less than 10, and you have a min idle speed. For the initial butterfly opening I cut a strip of paper a 1/4" wide and set the throttle idle setting so when the paper is pulled through the butterfly opening with a minimum of effort. If it tears the paper open it up. So now the engine starts and will idle. This is a good start.

Belive it or not..I finally got my idle right with the 35lbs GTP injectors. I knew I wasn't going to run a rich idle. I even have a ALDL scan of it.

The Question I had was why would GM make 3 dam talbes in the first place. Why not just 2. Well I started thinking and its because the idle tables are to try and keep the engine alive. Ever notice a rich value(high VE) on the high vacume high idle side of Idle VE tables??.

And your right about the EGR. Thank god the 8F code has the same values regarless of EGR.
My short term and long term at 128. My IAC count is at 10 at 42-43 KPA and 825-850 rpm.
O2 volts hover at .45. This is verry helpful. All this without messing with the Fuel flags.
I thought highway mode is desable by defalut from the factory since EPA found out about GMs little trick.

And I always thought it was good to go lean and add than go rich and take away since it would be a little trouble some to see a result from the unburned fuel left over messing with everything. I know I had..till I ran lean..then went back.

I would say if using a code to work with rookies would be the $58...its well documented. Or the A1 if you have full docs of them.

Question..On idle VE..i've notice zero values (hex 00). Would idle VE tables be desabled if all Idle VE tables were zeroed out (hex 00).

[Mars]

Turbo, would you mind sending me a copy of your .bin file? My idle goes high - low - high - low oscillates like that and it's annoying... My air fuel gauge stays pegged at rich, so my O2 voltages are in the .90 volts for sure...

Here is the binary I am using with right now :

http://www.domesticcrew.com/marvin/Cavalier/logs/Sept2lowidle.bin

I wouldn't mind comparing it to yours a little.

[TurboGTU]

Well I see you still have your fan 1 and 2 off set points at 25mph..???. I see your problem. TOO much fuel from Too much VE on your Base VE table F30 (VE vs RPM) From 0-2000 rpm your VE is too high. Lower it. Don't know how much my code will do you much since mine differes from your setup TOOO much. Well I'll shoot it down. I'll also email you next. Its Sappyse107s post after all. Maybe start a new one.

[sil]

ahhh..on a friends puter seeing as i dont have internet right now

in the DF code how can one adjust there shift points, firmness, and anything else thats related to transmission control, where do you look and can you explain what to adjust to get certain results

thanks

[SappySE107]

There is nothing for firmness. Under tables, F31 trans you will find the shift points. The perf/snow shift is worthless unless you have the 2nd gear start switch that switches to those values. There are also values under the constants for F31 trans. I really don't use GMPCM for the shift points so I don't know where the spark retard settings are located in it right now.

[sil]

did you end up finding the tables for trans control ?

[SappySE107]

In what code? I have them for DF but not the memcal 3100 as I dont have the file.