yea its 03 lb7 and my buds is a 01 lb7 would it still work .

 

it should. you will have to do the VATs relearn though if you dont have Efi Live or a Tech 2:

[Try to start it, then turn the key back to run. DO NOT TURN IT TO OFF.

Wait 11 minutes (time it).

Try to start again, then turn key back to run.

do this a third time

On the third cycle, it will ignore the VIN differences in the various modules and will start]

you may have to do this again when the ECMs go back in their respective vehicles too

 

i have two hot battery ,pretty new ,checked charging sys good , i just checked another lb7 ,the desired frp was much higher at 1500 rpms and at idle .???? does the fuel pressure sensor tell emc what to set the desired frp???? .or what sets frp. thanks for inout

 

the ECM has "maps" or tables it references/looks up to determine what pressure to run. this is based on RPM and commanded mm3 (fuel quantity). fuel temp, engine temp, altitude and some other perimeters make adjustments to this table

the ECM monitors the pressure sensor to see where it is at and then looks up another table to determiner how much currant it needs to adjust the regulator located on the CP3 high pressure fuel pump.

it then continues to monitor the pressure and uses a "feed back" method to make adjustments to the pressure regulator to keep the pressure matching the tables as best as possible.

there is also a limit as to how much this pressure the ECM is trying to control can differ from the map (table) before it will set codes and de-rate the engine

when monitoring fuel pressure you normally watch the desired (what the ECM wants) and the actual (the true pressure) and these should not differ by more then a few hundred PSI. it can have a slight delay of a few thousand PSI when pressing on the throttle but should quickly recover. most healthy fuel systems can maintain a difference of less then 100 PSI while in a steady state cruise

clear as mud?

 

i just cked desired frp again, idle 40 mpa??1000rpms 47 mpa don't know psi to mpa difference. the lb7 i checked had desired psi at 60 at 1000rpm . i rpl frp sensor first thing when i started this mess thanks mike

 

thanks 04 lb7 ill have to tell him to give it a shot. im going to keep watching this posting see what else everyone is thinking about the symptoms and possible solutions.

 

i replaced a fpr on my lb7 when i had it and looked at everything come to find out the new fpr was bad.

 

i found conversion mpa to psi my pressures are close to the lb7 i cked this am

 

145 PSI to 1 MPa

i need to know what mm3 the engine was running at to see if that is correct.

40 Mpa at idle sounds about right. the one at 47 Mpa/1000 rpm seems ok but maybe a little low. the one at 60 Mpa looks fine to me but need to know what mm3. it has been a while since i logged my LB7. i think it was something like 15ish mm3. on the maps that would place it at

attached is a map from an 02 LB7 os. this may not be the same as yours but should be close. dont worry to much if it is off a few Mpa as mentioned above there are some things that will make adjustments to the base map



02 LB7 Base Fuel Pressure Map

 

what were the symptoms of the bad fpr ????