Live data scanner: engine load goes from 0 to 100 nothing in between

[minisuper666]

So I hooked up my 172 to a live data scanner to check my lambdas (I ran a spark plug non-fouler in 2nd lambda and wanted to make sure I was getting the right readings to fool the ecu, it worked BTW).

Anyway, as I was scrolling through the live data, I noticed that the engine load at idle was 0%. I turned on lights, aircon, stereo, defogger, and the engine load remained at 0%. I blipped the throttle and the load jumped to 100%. Took the car out for a ride and sure enough, the scanned only showed 2 different values for engine load: either 0% (no throttle) or 100% (any amount of throttle). Read the values on the megane and sure as hell, it read 20%-ish at idle and the values rose as I turned on the a/c, defroster, etc.

So far, I've checked:

1.- Values of map sensor look ok, 30-ish kpa and goes p to 80 when I boot it. Compared these values against my f4r'd megane, even swapped the MAP with the megane, everything looks ok.

2.- Throttle %, something seems odd here: when I floor it, the scanner reads 66% maximum travel. Is this right? I know most cars don't really go to 100% here, but 66%?

I dont have any trouble codes, basically the only odd thing I have is that the car judders a bit when in 1st gear when the clutch bites, I have to rev it a bit on takeoff basically.

Anyone encountered this problem before? What's wrong????

 

[oliver9523]

I only get 66% on my 172 too, but when looking at the butterfly valve in the throttle body it's wide open so I put it down to the cheap reader I bought off ebay not reading it correctly.

 

[minisuper666]

Well my main issue is not the throttle value (66%), the issue is the engine load going from 0 to 100%, nothing in between. How is engine load calculated? I thought it used the MAP sensor, but something is surely wrong if I'm only getting these 2 values.

Also, when I hook up the reader to the megane the engine load % acts exactly the way you'd expect.

Any thoughts much appreciated

 

[MicKPM]

Generally, you are correct in that the MAP Sensor values are used to determin engine "Load" in the eyes of the ECM but do not confuse the "Engine Load" reading on your equipment for those of the "MAP Sensor Pressure" or "MAP Sensor Voltage" readings as they're different and on seperate channels.

What "Generic" reader are you using just out of curiosity? It is most likely possible that the reader itself supports this "load information" for some makes but the car you're using it on doesn't output it hence no reading.

Mick

 

[minisuper666]

It's an Actron, not really a generic one, dont know the model but do know that the cheaper actrons dont have live data readings.

I'm not confusing the readings, actually I've stated before that the MAP reading comes in KPa, there's no value for MAP sensor voltage. And the thing about the engine load %, it does give an ouput, but the output is not right: it's either 0% when I'm not pressing the gas pedal, or 100% for any amount of travel of the gas pedal.

So, I am getting an output, but I'm a bit concerned about it. The scanner does not calculate load, it only takes the readings from the ECU, so I'm concerned about why am I getting these load values. The MAP readings are fine and all, so what else could cause the ecu to be showing a 100% reading?