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Use spare tps for fuel trim?

Posted: Mon Feb 19, 2018 12:27 pm
by molecular bob
As I have a spare tps, could i use this as a quick and dirty fuel trim control, wired via an analogue in? I want to dial in a fuel map for different sized injectors and fuel pressure? I have calculated a % change due to these changes, but was thinking of giving myself +/- 5% to play with to get the afr back to where it needs to be if the maths is wrong.

If the logic is sound, can you define the cells you trim in the software or is it global. I know i could do this in mapping, but a single rotary i can adjust on the fly would be useful to avoid having the laptop in the car.

Re: Use spare tps for fuel trim?

Posted: Mon Feb 19, 2018 1:44 pm
by Alex DTA
You can't use TPS2 for that.

You an use any of the analogues though. Pick one (TPS2 is on analogue 2 just to confuse things), fit a pot to it, then set the fuel adjustment you want for the range.
This is applied globally, so will do what you want to.

Re: Use spare tps for fuel trim?

Posted: Tue Feb 20, 2018 4:53 am
by molecular bob
Cheers Alex,

should have looked at the wiring diagram before posting.

Re: Use spare tps for fuel trim?

Posted: Tue Feb 20, 2018 8:06 am
by Rob Stevens
Or better still build your self a knobs box. But you'd have to have the computer with you I guess.