Whilst using an OBD2 Scanner on my 2002 Honda Jazz (UK car) I have discovered that when my throttle body is fully open (against the stop) the TPS only displays 90.2% and the butterfly is also not fully open.

Would there be any benefit in modifying the stop to allow the throttle body to open further and achieve 100% WOT on the TPS?

I am thinking that i may be able to improve performance ever so slightly...
Does anyone think that this is a sound idea?

Looking forward to your comments.
Steve.

 

I decided to have a go this afternoon, rather than wait for an answer, lol.

After removing the Throttle Body i carefully filed a small amount off of the throttle end stop to allow the throttle to fully open.
I re-assembled everything and checked the new throttle position using my OBD2 scanner. The TPS now reads 91.8% with the throttle fully open (previously 90.2%).

I'm not sure if it has made any difference to the overall performance, but the engine did feel a little more stronger on my drive home from work this evening. Probably all in my head, lol.

Have any of you guys tried doing this mod to your throttle bodies before?
It would be interesting to hear what your findings are...

 

i checked mine, able to go 100%

 

Do you have the UK L13 from the GD1 or do you have the US L15?

The official Honda Jazz/Fit shop manual states:
"Check the throttle position with the scan tool. There should be about 10% when the throttle is fully closed and about 90% when the throttle is fully opened".

I don't understand how your TPS can read 100% if it is fitted with the Honda L13 engine.

As i mentioned, my throttle measured 90.2% against the stop (as standard) and the throttle "butterfly" (or whatever its called) was not fully open.
I had to file some material off of the stop to allow the throttle to open fully (with the butterfly parallel to the air flow), but at this setting the TPS is reading 91.8%, not 100%.

 

throttle percentages are relative numbers and don't really mean anything on their own... the values to look at are the throttle volts...

 

Ah, that is a very good point.
I'll have to check it out.

 

excuse this dumb question. but what is throttle voltage? what does it represent? i quite understand the throttle opening percentages, but not throttle voltage.

 

throttle percentages vary from car to car... some don't go to 100%, some do... some idle at 25%, and some idle at 5%...

voltage will be a more constant value from car to car... the sensor can only go so low and so high...

 

errr, but shouldn't the throttle percentage be similar from one fit to the other? provided they are the same type and engine?

also, i still use cable for my throttle... lol... thanks for the explanation...

 

^ you'd think so... but alas it isn't... however, the throttle voltage is the same from car to car...

 

curiosity is piqued... i'd do some research on it... thanks alot apexanimal