I have installed a set of Injector FX 1000cc injectors a bloke supplied and having some trouble with AFR's. Data sheet was supplied with them and i have them set at
low slope at 126.08280 lb/h
high slope at 114.38640 lb/h
breakpoint 0.0000270 lb
min PW 0.642 ms
Car started straight away and idles ok but its running rich while coasting in gear (manual) down hills, its commanding 16.1 but afr's are 13.
Did you also change injector dead times to suit new injectors.
Try logging with vcm scanner, injector pulse width in mS.
This will give you a clue at whats happening. Look at pulse width on decal. Its usually MIN pulse width + injector dead time. Try decreasing it by .1 and see what happens
Thanks Luke, I have the injector pulse width logging and it was at 0.6ms so i changed it to 0.3ms and problem solved.
Now i have fitted a 3 inch turbo back exhaust i just want to clarify somethings, changing the low slope to say 120.08280lb/h will increase fuel and richen the AFR at idle and cruising and changing the high slope to say 110.38640lb/s will increase fuel and richen AFR's at WOT, is this correct?
Yes thats correct.Originally Posted by Makaveli
I use the wideband sensor reading to tune the high slope. I have found its best to do that first either at the drag strip in 3rd gear or a quiet back road. I think you really need to get into 3rd WOT to get a decent reading, 140-200kmh.
Then do the low slope next. I use a custom table in vcm scanner with the LTFT and I adjust low slope until all cells average 0% trim (some will be +, some will be -)below say 20% throttle then fine tune with the tuning correction table. I am not sure if this is the correct way to do it but it works for me.
Another way to tell where low slope is affecting LTFT is to make a large adjustment say +10 or -10 and see what changes it makes. I am using deka 60lb injectors with 4 bar reg so they are about 75lb and the low slope only really affects below 1500rpm.
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