Ok here goes my super newb question... is a higher number than 128 telling me I'm to rich or too lean? I had a few around 150.

 

Numbers larger than 128 mean that the ecm is adding fuel... which means that you are lean

Numbers lower than 128 mean that the ecm is removing fuel... which means you are rich.

I like to think of it as a gas pedal. More foot is more gas is more (higher) numbers.

Did you read the stickies up top? I know it is tough to sift through all the info but it is all good stuff

 

I have over and over but I tend to forget with all this new info I'm trying to retain... alot to take in.

thank you.

 

150 might be maximum BLM. you could be very short on fuel. 150/128 = 1.17consider adding 25% more fuel in those cells. seems like tuning from rich to lean is always easier than vise versa.

 

Well see the thing is it's pig rich... my 02 censor was reading .004 volts to about 0.140 because my o2 wire was rubbing my header and melted the damn thing but one wiff of the exhaust and I'm light headed... just need to cut and solder it.

But could you explain to me what the value of 1.17 means and how to use that to convert into percentage of fuel to add/subtract... I could really use some of those little tricks from you tuning vets.

 

I'll tell you but you have to promise to read the stickies a few more times. Read the 730 part throttle tuning, section 3 or 4. It talks about this stuff.

Lets say your data log says rpm=1825, map=50, and blm=146. You look at your ve table and find 67.32 in that cell. The blm is telling you that 67.32 is not enough fuel so the ecm is adding fuel...

take 146 and divide by 128 (this is the ideal midpoint for the blm). 146/128=1.14. Now, in your ve table, click and highlight the 1825-50 cell. Open the toolbox if it isn't already showing. Set it to multipy, put 1.14 for the amount and click "execute" button. This will change the 67.32 to 76.74.

The trick is to have many cells to change so you can get a good idea for what is going on in the other cells. I made up a table printout in Excell and write down all the multiplication factors before making any changes. This process helps me see what is going on and I use it to make sure I have enough datalog to do the majority of the ve table. I then fill in the other cells with good educated guesses. There are several tools you can download to fill in the other cells.

Good luck

 

Gracious senior!

mucho appreciato....

damn I'm a good spanish speaker er er er.

 

i would also suggest looking at a stock .bin so you can graph it and see how it looks as fars as peakes and valleys. i did not do that and and after numerous VE table corrections it needed smoothing. when we log we dont hit all the VE cells we would like to so we need to consider the smoothie.

also it is said to not log the same route. consider differing logging routines if possible. i logged the same route(to/from work) way to often.

 

got another question... I was reading the "how to fix some of those common idle problems" article and learned alot of useful stuff but that is for a different ecm and In my 7747 I don't see a way to change the median voltage on my o2 sensor so how do I do it with a 7747? Is there another way to minipulate the idle for a cam with more than stock overlap. I smoothed out my ve tables and now it wants to idle and my blms look good and the motor seems pretty happy and free. I fixed my o2 and it made quite a difference but it still surges, stalls from over rich, and wants to die after stabbing the throttle and letting it settle down.