im all new to this and trying to get my tune at least workable till I get my feet wet here. 04 mustang. now has blower and return fuel,3.5 tube with slot maf,etc. problem is, all info ive found contradicts each other,and I don't know which if any data ive used is even remotely right so that I can continue. I have the car running by scaling the original maf up by 50%. ive used the siemens deka values for 80lb injectors,but if I use the pressure offset value at 40 lbs(1.0) the car overfuels something fierce on startup. but if I change it back to what it was (.0625) it will run decent ,although lean. so until I know which (if either) of those are right,moving the maf doesn't make much sense or Ill never end up with anything to work with.
when swapping to return fuel systems you should always keep the fuel pressure sensor on the rail and keep the fuel system setup for stock returnless so any fueling pressure issues will be compensated for as well as for safety
put the actual siemens deka 80lb data in your tune. Then go cut the engine size scalar in half as well as the injector high slope, low slope and breakpoint. Set the minpw to 0.
ok that helps. I had seen I will have to scale the injector slopes and such,but was trying to wait until I could at least get a handle on getting it to idle so I knew I had the right data. I was unsure of how scaling works just yet and didn't want to make even more problems.
so if putting the 80 lb pressure offset of 1.0 back in is super pig rich, I assume I need to scale back my maf a ton? half the stuff I read says the maf is not to be touched,and to adjust injector slope, and others say the opposite.
as far as my rail sensor,i do plan to put it on, but currently my rails have no where to put it,and I just want to get where im comfortable getting this where its halfway right first. I can always remote mount it after I get it drivable enough where I can start logging pulls. as of now, its not there, and I just have my injector pressure offsets set all the same and have a boost referenced regulator. im not exactly sure I have my fuel pump setup right in the tune either for this, and not sure if that's causing me an issue either.
well, all morning I changed things to try to make this work. and all ive done is wash gallons of fuel through the motor. no matter how lean I cut the maf or load failed maf table, nothing matters as long as injector offset multiplier is 1.0. I just put the stock tune back in and parked it and it runs better. the stock multiplier is .0625. that's a huge difference.is there anything else wrong here?
thanks a ton for the reply. I had to walk away until I get some solid info . im referring to the injector offset vs pressure,as I posted in the above pic. I set them all to 1.0 (as it shows on the data sheet at 40lb). since I have a return system with no rail sensor, I assume that is the correct way for all the offsets other than voltage. or is that not the correct way to set up a return system? im not exactly sure how that's supposed to be setup since the ecu doesn't have a way of knowing the pressure. I have cut the maf in half 3 or 4 times the other day and got no where. maybe I just quit too early.
I have all photos disabled on the forum preferences so I cant see any thing you posted.
the offset vs pressure multiplier is fine being null
with no rail pressure sensor and the fuel pump system type and returnless aystem type both set to return style the ecu uses the default fuel pressure of approx 40psi
if you cut the maf in half 4 times then that means you would have ended up with only 6% of what you stated with thats a 94% fuel correction which is huge which means you had 16x the amount of fuel and you were still rich?
well, now that I think about it, maybe it wasn't half. I was slightly irritated when I quit. guess ill start fresh and try again. what confusesme now is that you say the multiplier is fine at 0. but it makes an absolutely big difference when I change it to .0625 from 1.0.when I first got it running it was set at .0625. I had to ADD about 30-40 percent to the stock maf table to get it to stay running.now if I change it back to 1.0, its quite the opposite. the way my luck is going, its probably something wrong with the mpvi2 again. this thing has been nothing but headaches since I decided to buy it months ago,and still haven't gotten anything done.
Did you ever get this sorted out? I'm currently working on a turbo setup with deka injectors. I had similar problems due to incorrect injector data and maf data. I'm driving mine and fine tuning the maf. I had wrong injector data and was pouring fuel out the exhaust.
I have not got anywhere on it at all. haven't got any different info that I know is right to try and have not had the time. results have been terrible so far,so I haven't had any interest. what data was wrong on yours?
Any headway on this? I?m having a similar issue on my 99gt, it?s a 9.5:1 build stroker ported pi heads, cms 2.5 blower cams, I?m running 3? piping with an hpx-e blow thru maf and 80# injectors. The car is a return fuel system set at 40psi and I can?t seem to get it to idle or run leaner than 10.5 on the wide band, I?m on my third set of plugs...
Last edited by boostednewedge; 09-28-2020 at 06:49 AM.