Quote Originally Posted by lionelhutz View Post
It'll just be an approximation. You are recommending to watch voltage and guess at the %TPS because just throwing in a calculation to get a direct approximation of the %TPS isn't good enough? What the fuck is the difference?

There is no %TPS. You have to basically make a best guess at it. The easiest way is to throw a calculation into the adx file and get a number. It won't match exactly what that ECM is using internally but it's at least an easy starting point. There, does that suit you?

Now you're throwing in arguments about how newer PCM's work, which have no bearing on using a '7747....
Look, I've used the '7747 quite a bit, I've tried a lot of things, one of which was to get an accurate TPS % value in the datalog. After many, many attempts to get something that was even a good approximation, nothing ever was, not even close. Changing the formula, adding removing offsets, etc. It was pointless in the end.

To understand how TPS % output works, referencing other GM ECMs is most certainly valid, to contrast how things work, to help further explanation, since it seems that you only have experience with newer ECMs that have this ability built in.

Keep it civil, or you will be taking a break from the site, we try to keep things nice here and don't tolerate hostility.

I'm trying to explain things to you nicely, but you don't seem to be able to grasp that it's just not as simple as you believe. I too thought that it would be simple to put a formula in manipulating the TPS voltage, but after attempting it myself (going against what other people had said), I confirmed that it's just not that simple.

So in your recommendation, when the throttle is closed and you get a TPS% value of around 12%, how is that helpful? Ok add an offset, now the rest of the range is off, reading low, because you have to take away what ever it was over at the beginning. So now change the formula, oh wait, now the offset is wrong, readjust that, and the range is off again. So now we look at the other end of the scale, and see that it's not reading 100% when the throttle really is, play around with the formula to get that right all while trying to get the other end to stay the same and hoping that the scaling through the middle actually works as well...

Go and play with it if you want, I won't waste my time any more and will not recommend to anyone else to waste their time trying to set up a TPS % value based on the stock ALDL datastream of the '7747, it's an exercise in futility. If if someone was to get a TPS % value that worked right for that truck at that particular point, then the TPS needs adjustment or replacement, the whole process starts all over again.