I started messing with injector bias because I went from stock bpw of 148 for 305cid to 142 for my 273cid and all numbers up to 153 and still have lean at higher kpa map so after reading some about injector bias I figured I try it and it definitely improved throttle response and got rid of most of the off the line stumble it had and it gave me some rich blm numbers for once so it thought I was going the right direction.I just have no way to copy a starting point because my set up never came factory in anything the way I have it set up.ie tbi on a pfi engine.from what it read the heads on the tbi are not the same as pfi and I don't know but doubt cam would be exactly the same.but if I use the calculator for bpw I get 144 for 45bl/hr injectors. So thats what I started at with the bias at the stock .4.it ran lean and like a miss and not near enough fuel.I'm hoping to get the 49lb/hr injectors in it as soon as weather permits and put bpw at 133 for those and not sure if I should put the bias back at stock setting. It's st least been a lot better on fuel snd more fun to drive.thanks for the tips.I'll keep playing till I get it.I got a zif socket and ten more chips and laptop car charger so at least now I can get 45 min logs on my drives to and from work.and I have a fairly large hill with a good incline that's about a mile or more long so that gave me more data collection range i couldn't get on flat driving.I don't know where the power curve is or should be on this engine.the stock ve table didn't give good results.the 273 may be close in hp and torque to a 305 but the power comes way earlier in the rpm range.I doubt I'll ever Rev this engine to 5000 rpm.its rated at 180hp at 4400rpm and 245 lbs at 3200rpm.so it's all been guess work for me and getting help on here has been great.
Reply With Quote
Bookmarks