Before I knew about PROM burning, MAF tables, etc., I (probably stupidly) removed the screens from the MAF sensor on my car. Now, I know that it isn't calibrated properly because of the change in airflow. I read Grumpy's article about recalibrating the MAF and also his article on the GN site, and I have two questions.

1. Can I save this adjustment for later? Meaning, can I get the car running where it should be (~128 BLMs) and then tinker with the MAF tables, or will it throw off my previous tuning?

2. Based upon the articles, it seems like tuning the MAF is a guess-and-check method. Is this correct?

 

1) If you make no intake tract, or cam changes the MAF should be close.

2) Guess and check without a WB. Having a WB makes it MUCH easier.

 

Decrease your FI constant by 10% or so. That'll take care of fin & screen removal right quick. Later on you can get into the MAF tables & do it right...

 

<sigh>
What's wrong with just doing it correctly?.
Every notice LONG TERM, that the quick fixes, aren't?.
For the time spent fooling with wrong items, that time could be spent on working on the correct items, and save dong things twice.

Tuning is about habits.
Get into the wrong mind set, and you can waste a whole bunch of time walking around in circles.

In a way Correct Tuning is a form of Zen. You really have to clear your mind, and just do what the engine's telling ya. Take your notes, and look for trends, get that down, and it gets MUCH easier and faster.

 

Thanks for replying, Grumpy and Craig. I really do need to build a WB if I plan to seriously get into chip burning. Craig, I've only removed the screens -- I haven't touched the MAF fins. With that in mind, would I still take the FI constant down a full 10% or more like 5-7%?

 

Grumpy, it looks like we both replied at the same time so I didn't see your second reply until now. After reading your post and thinking about it, I see that changing one thing to compensate for another (FI constant, in this case), would still negate some previous tuning once I get to the MAF tables.

 

Good point... Keep forgetting that while it might get me by, it will serve to confuse others...

 

got a question for grumpy.

aside from actually messing with the maf. BS'ing the injector constant is really so bad ?? i dont see how. if the corrections are correct for the engine in question then changing the inj constant will have a global effect on fueling. it also means that all calculated values will follow the same slew.

 

Not Grumpy, but, there is more then just the BPW calc being tied to the airflow term. By changing just the injector constant all the other calcs that depend upon the true airflow are now skewed.

RBob.