Oldgamer Posted June 15, 2005 Report Share Posted June 15, 2005 Ranger: I think the same, that PCM uses factory spec fuel pressure for the calculation. But that is my guess, until Guru or somebody else says that for certain. Adallak talking about difference 5%, which is very possible with 41-45 PSI difference from car to car. KHE: I didn't tell you that ECM controls the fuel pressure. I didn't tell you that fuel pressure is different from injector to injector. I told that fuel pressure is slightly different from car to car, and it is not absolutely constant. That can make a difference in calculations around 5% easily Link to comment Share on other sites More sharing options...
adallak Posted June 15, 2005 Author Report Share Posted June 15, 2005 Ranger: I think the same, that PCM uses factory spec fuel pressure for the calculation. But that is my guess, until Guru or somebody else says that for certain. Adallak talking about difference 5%, which is very possible with 41-45 PSI difference from car to car. KHE: I didn't tell you that ECM controls the fuel pressure. I didn't tell you that fuel pressure is different from injector to injector. I told that fuel pressure is slightly different from car to car, and it is not absolutely constant. That can make a difference in calculations around 5% easily Oldgamer, The problem is that those 5% are always in favore of a gas station In other words nobody noticed that the actual fuel used would be less than the computer calculated....it is always more. The saddest thing in life is wasted talent Link to comment Share on other sites More sharing options...
KHE Posted June 15, 2005 Report Share Posted June 15, 2005 KHE: I didn't tell you that ECM controls the fuel pressure. I didn't tell you that fuel pressure is different from injector to injector. I told that fuel pressure is slightly different from car to car, and it is not absolutely constant. That can make a difference in calculations around 5% easily One of the reasons for the slight fluctuations of the fuel pressure is the change in engine vacuum which affects the fuel pressure regulator. The point I was attempting to make with the injector statement was there is a slight pressure change as each injector opens/closes that would account for slight changes in pressure readings. Another factor that would affect the gage needle stability is the damping mechanism used in the gage construction. Kevin '93 Fleetwood Brougham '05 Deville '04 Deville 2013 Silverado Z71 Link to comment Share on other sites More sharing options...
Oldgamer Posted June 15, 2005 Report Share Posted June 15, 2005 KHE: Sure, fuel pressure can't be absolutely same for a lot of different reasons. I only want to know what variables computer takes into attention for calculations and what it counts as constant. adallak: Computer should take price into attention too and make correction to calculation!!! Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.