hello again.. i got my car up and running on a stock chip. now time to tune. i have a 88 firebird with a 350 tpi. cam is 230/234 111lsa .474 lift. ..... 160/202 heads, full 3" exhaust, shortie headers NO EMMISIONS


i fired it up using the stock chip, and am now ready to tune for everyday use. im figuring i need tou use the $6E and ARAP bin.. im going to try that first, and if that dosnt help out, what should i do to lean it out o yeah... at 2,000 rpms Air Fuel was 10.0-1

 

If you are running larger than stock injectors, one of the first things to do is set the injector constant to match the flow rating of the larger injectors to get you in the ballpark.

If you are running the stock sized injectors, then something else is likely causing it to run that rich. Is this in open loop or closed loop? What is the CTS reading? What do the BLMs look like?

 

i have not got a chance to datalog, so i have no clue for any of those...
i have stock injectors, and that was on stock tune... only during inital start up of a new engine... im thinking i need to upgrade to the $6E and uses ARAP? but looking at arap, spark is near 45* advance that seems way too much to me or am i wrong?

 

At heavier loads / higher RPMs, ARAP looks like it is about 33* - 35* (without additional PE spark), so it should be ok to start with.

I suggest taking it easy on the throttle, data log some cruising, and see where the BLMs are falling. Check your data logs for any knock counts / knock retard, and also read your spark plugs - they will tell you a lot about what's going on .

 

is that added spark on top of what my base is? or will that be total no mater what i set dissy to? i was adding the 10* adv im at already

 

That will be the total spark advance, but is based off of the programmed initial spark advance. For example:

You set the initial timing to 6* btdc. The chip is programmed to 6* btdc. Total spark advance will be whatever the tables are for that particular load and rpm (+ or - any correction for PE, knock retard, etc). Say 35*.

However, if you set the initial timing to 10* btdc but the chip is STILL programmed at 6* btdc, you will have added 4* of advance across the board, but the ECM will still "think" it's at 6* initial and add 29* to hit the 35* from the table. When it adds 29* to the ACTUAL initial of 10*, it'll be at 39* instead of the 35* that you want. Your data logs will not read correctly, either.

Hopefully my explanation isn't too confusing

 

if i read it enough times., i will get it... once i get a light on my car, and find where i like the base timing to be how do i change that in the chip? or should i just set it at what ever the chip is set to (also where might i find that??

 

In Tuner Pro, it is listed in the "Constants / Scalars" section under "Spark Reference Angle - Base Timing". This value should definitely match whatever you set the distributor to. Stock setting for ARAP is 6*.

 

sweet thank you! ill update as soon as i get a chance to go back out to car (work and child)
also will i have to go into the SA table and modify, say i set it to 10 from 6, will i have to subtract 4* all around or will it do this automaticly
(sorry im not near my laptop to do trial and error

 

No - you will not need to modify the SA table for that reason. Whatever initial spark advance you set the program to, that's the value that the ECM will use as a base in order to get to the appropriate total advance value in the table. So if you program the advance in the .bin to 10*, the ECM will know to add 25* in order to get to a total advance on the SA table of 35*.

If, however, you were to leave the programmed initial spark advance at 6* in the .bin, but set the ACTUAL initial advance at the distributor to 10*, the ECM would think it needs to add 29* to get to 35*, when in reality, adding the 29* to the ACTUAL 10* would put it at 39*.

Total advance is total advance in the spark advance tables (how's that for an in depth explanation ). The ECM just needs to know where it is starting from in order to add the correct amount of additional timing to hit the total advance figure. Adjusting the initial spark advance AT THE DISTRIBUTOR (not in the .bin) is a way of globally raising or lowering total timing across the board.

 

you my friend, are awsome.. i will update once i get back to the car this weekend. THANKS!!

 

I'm glad I could help!! This forum has helped me tremendously, so it's nice when I can actually help someone else .

 

hey, 87-
hope you still check this thred.. i got the base timing, and using arap, also $6E.. couple questions..
im still rich as hell in uppper rpms.. can i use the MAF scalars to adjust for this, by using the sliders, or should i go into the tables to modify. also which way do i tune, make numbers grater or smaller to lean?

also i noticed 6e doesnot use the 9th injector.. do i have to unplug it as sudgested? or can it stay hooked up
thanks

 

Yup - still here

There are a few ways to adjust that fueling. Adjusting the scalar table will globally move all values for the corresponding MAF table, which may or may not be necessary. Also, you need to pay attention to the surrounding tables to make sure that the ending value of the previous table matches the starting value of the next table and so on and so forth. Adjusting the scalars can get a little tricky in that way. Going into the actual MAF tables and making adjustments is probably the better way to go. Raising the gms/sec number will make it richer, lowering the number will make it leaner.

There is also a Power Enrichment by RPM table that you can use to adjust enrichment percents by rpm in PE mode (if it is in PE mode that you are seeing the rich condition).

The 9th injector is not controlled by the .bin, so I suggest unplugging it since the $6E bin has start up enrichment built into it.

 

cool, i hit a snag with the oil pressure, but found to be a bad sender, so maybe this weekend ill get to do some road tests

 

well, i got some road tests, andhere is what i found. at idle, i am way too lean.. (may be my timig.. ) but while cruising im around 11.0-1 what would you do to help this condition... i know that certain tables controll certian things, but i cant find the thread about that. im guessing rise the numbers in the idle table and lower all the rest? could you help me out with what table does what please?
TIA

 

Is this in open loop or closed loop? I would guess open because you should see some correction happening in closed loop to get you closer to 14.7:1. What do the BLMs look like?

Fueling is controlled via the MAF tables 1-6. The first 4-6 entries in table 1 are generally where the engine idles. You can adjust those gms/sec numbers up or down (up if you need to richen it up) for idle. You definitely need a data log to see where (what airflow readings) it is running rich, and then adjust the gms/sec accordingly.

Those tables are used by the ECM as a "look up". When the MAF sensor voltage = x, then gms/sec of airflow = y and the ECM will fuel accordingly. If you lower the gms/sec value for a particular voltage x, then the ECM will read LESS airflow y (that you entered) and lower fuel.

 

im having issues now with the data log, TP is shooting me an error, saying it cannont innitalize the serial port. most likely because im using USB. any clue how to work that out?

 

I haven't encountered that message before, so I'm not much help there. Did you try reaching out to Mark? He might know.