S80 pro zetec runs lean at 5% throttle

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Tigermickcate1
Posts: 12
Joined: Fri Apr 22, 2016 1:13 pm
ECU Model: S80 Pro
Distributor: Private sale
Firmware Version: 52

S80 pro zetec runs lean at 5% throttle

Post by Tigermickcate1 »

Hi all , I'm running S80 pro ST170 zetec on hayabusa throttle bodies 3.9 bar fuel pressure , when ever I hold throttle at about 5% it runs lean 17 or off the scale but reads fine if I fully lift or accelerate anyone else had this problem...?
Rob Stevens
Posts: 1247
Joined: Thu Jul 28, 2011 4:10 am
ECU Model: S100 Pro
Distributor: None-Coil On Plug :)

Re: S80 pro zetec runs lean at 5% throttle

Post by Rob Stevens »

It's not a problem, its mapped wrong
Tigermickcate1
Posts: 12
Joined: Fri Apr 22, 2016 1:13 pm
ECU Model: S80 Pro
Distributor: Private sale
Firmware Version: 52

Re: S80 pro zetec runs lean at 5% throttle

Post by Tigermickcate1 »

Yeah I did think that but the figures all look reasonable and even closed loop won't bring it back to lambda target, so was wandering in anyone else encountered this problem , I was thinking maybe injector or fuel pressure
Rob Stevens
Posts: 1247
Joined: Thu Jul 28, 2011 4:10 am
ECU Model: S100 Pro
Distributor: None-Coil On Plug :)

Re: S80 pro zetec runs lean at 5% throttle

Post by Rob Stevens »

Closed loop has limits set on it regarding max and min corrections.
If you are using bike TB often you have set the initial break points very close like 0%, 2% 4%, 7% ect to overcome the fact that the butterflies have an aggressive closed position. Although the 'bussa ones are not that bad.
katana
Posts: 455
Joined: Sun Jan 27, 2013 6:08 pm
ECU Model: S60 Pro
Firmware Version: 29

Re: S80 pro zetec runs lean at 5% throttle

Post by katana »

What injectors fitted? Why the hike in fuel pressure - 3 bar is norm. Busa TB's are BIG! - maybe too big for a Zetec where 45mm is usually enough for 200+hp. @52mm the Busa ones are probably capable of 300+hp NA!
Tigermickcate1
Posts: 12
Joined: Fri Apr 22, 2016 1:13 pm
ECU Model: S80 Pro
Distributor: Private sale
Firmware Version: 52

Re: S80 pro zetec runs lean at 5% throttle

Post by Tigermickcate1 »

Cheers Rob I understand what your saying and will try different settings , katana standard st injectors 315cc, the 3.9 was a figure I found on the net but will drop it to 3 , I went with the busa throttle bodes so if I decided to supercharge I wouldn't need to change them , but if there not going to work n/a I might have to
katana
Posts: 455
Joined: Sun Jan 27, 2013 6:08 pm
ECU Model: S60 Pro
Firmware Version: 29

Re: S80 pro zetec runs lean at 5% throttle

Post by katana »

Injectors ok - fuel pressure - check. My thinking behind the Busa TB's is due to the big hole, any minor opening of the throttle presents a larger proportion of air in - may only be marginal but as said above, tightening up the map resolution low down may help? If you use MAP instead of TPS for load may assist if available? Are you using fixed cam timing or movable - maybe its a cam timing Vs air speed issue?
Tigermickcate1
Posts: 12
Joined: Fri Apr 22, 2016 1:13 pm
ECU Model: S80 Pro
Distributor: Private sale
Firmware Version: 52

Re: S80 pro zetec runs lean at 5% throttle

Post by Tigermickcate1 »

Yes mate I've got tps or map available so can try using map, still running the vvt runs well , thanks for the help you
zdrafko51
Posts: 22
Joined: Wed Nov 12, 2014 10:59 am
ECU Model: No ECU

Re: S80 pro zetec runs lean at 5% throttle

Post by zdrafko51 »

I know that it was a long time ago but have you solved your problem. I have similar problem, my car has zx12 throttle bodyes on a fiat 2l TC engine 8v (I know it is big for that engine, plan is to put 16v head, 8v is just for testing now and learning) and around 1000 -2500 rpm I have problem with lean mixture. I have TPS for load and increments are 2,4,6,9... it helped a little but there is still a problem.
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