OBD showing throttle position at 91% only when accelerator fully down.

[adam.]

Bought an OBD reader off Amazon, seems decent enough for £25. (https://www.amazon.co.uk/gp/product/B00VUW2PB4/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1)

Anyways, when I was having a play earlier I discovered two things.

1. I need a new primary O2 sensor.



2. My ECU only shows 91% throttle opening under full accelerator pedal press.



Is that normal when the engine isn't running, but ign on?

TIA !

 

[Johngreen537]

Might just need it calibrated mate.

Sent from my HTC 10 using Tapatalk

 

[spooke]

Pretty sure mine reads under 100%. I don't believe it will read 100% though? Curious now

 

[adam.]

Well that's just it, I don't want to be losing 9% of my throttle!

 

[wj51fut]

Check the voltage with a multi meter. WOT should be 4.5v

 

[kyle'87]

I fitted my new one recently.

When trying to calibrate it through Kpro readings I could only get either CT 0% to WOT 96% or CT 1% to WOT 100%.

In Kpro you can tell the ECU where the CT is and WOT is, only if your map isn't locked, like mine is

I've tried with the Voltage method but got some weird results.

As long as the voltage goes up steadily when you press the throttle pedal it just means it likely needs calibrating and not replacing, £70 odd quid for a blueprint copy from Tegiwa.

 

[discodave22]

I seen this too when I was in kpro, after doing my tps with a multi-meter. Mines was 99.5% throttle down, so I adjusted the nut that keeps the cable taught. Quicker if you have a mate to look on the laptop or obd reader and pressing the throttle.

 

[adam.]

So I AM losing precious throttle movement?!

Will have to get the spanners out.

And find a friend from somewhere!

 

[spooke]

So I AM losing precious throttle movement?!

Will have to get the spanners out.

And find a friend from somewhere!

Still wondering whether this is the case, I guess the easiest way is to take your air box/intake off and see if it is fully opening - If not tighten the cable.

 

[mattreay]

So I AM losing precious throttle movement?!

Will have to get the spanners out.

And find a friend from somewhere!

Even if you are losing 9% throttle movement you're unlikely to be losing power. Most DC5 ECU maps use manifold pressure as the measurement of load, not throttle position. The only time you would use TPS as the load index is when running ITBs. You're still likely to see atmospheric pressure in the manifold, i.e. full load, well before 91% throttle.
The stock Hondata maps consider anything above 80% throttle to be WOT. Not sure if the stock Honda ECU is the same.
If your OBD reader can measure it, get someone to monitor the MAP sensor reading whilst you floor it. Check it hovers around atmospheric pressure. If so, your lack of throttle movement shouldn't be causing you any issues.

 

[adam.]

Even if you are losing 9% throttle movement you're unlikely to be losing power. Most DC5 ECU maps use manifold pressure as the measurement of load, not throttle position. The only time you would use TPS as the load index is when running ITBs. You're still likely to see atmospheric pressure in the manifold, i.e. full load, well before 91% throttle.
The stock Hondata maps consider anything above 80% throttle to be WOT. Not sure if the stock Honda ECU is the same.
If your OBD reader can measure it, get someone to monitor the MAP sensor reading whilst you floor it. Check it hovers around atmospheric pressure. If so, your lack of throttle movement shouldn't be causing you any issues.

Helpful, thanks for posting.