I have a 1996 oldsmobile lss, well sort of! It has a 2007 buick Lucerne engine, 2000 bonneville 4t65e tranny, 1999 lss ecm, 2005 metal upper intake with the stock throttle body and most if not all sensors are new. Also it has new matched flow fuel injectors. Also it has the camaro dual piston brake upgrades. But the title says it'* a 1996, so we will go with that.

The problem is this:
Back before all the changes It had a lean code on bank 1. Also when you start the car sometimes you will get a loupey idle for a minute then it will go back to normal. This problem has never gone away no matter what. So I wondering if it is the fuel pump, it has never been changed. The car has 210k miles on it. So should I change the fuel pump?? The fuel regulator is new.

Will a late model fuel pump and guage sender unit swap in? (used)
Which fuel pump would you recommend?
Also does someone have a wiring diagram to build a fuel pump hotwire system?

thanks

i would look up the pressure specs on the 96 and the 07 and see if they are the same, if so you can just get a new oem if not you might have to modify a 07 pump to the 96 sender. did you get the pressure regulator for the 07? make sure if you take it apart the thing you check out the connector for the sending unit. alot of them have corrosion that can reduce power to the pump and cause issues

will look at the connectors. I'm using the stock 96 fuel rails and regulator also the matched flow injectors

you check pressure?

Turn the ignition ON ; the fuel pump should run for a few seconds. Check the pump pressure for the following specifications:
1987-93 vehicles, except 1993 VIN K: 41-47 psi (284-323 kPa).

1993 VIN K and 1996-99 vehicles: 48-33 psi (333-376 kPa).



Start the engine and allow it to idle. The fuel pressure should drop about 3-10 psi (21-69 kPa) due to the lower manifold pressure.

i will get a gauge to check it out

autozone has a guage for rent will know in a few

43-50 on the fuel pressure so the fuel pump is not the problem.
time to look at the tps?

any kind of vacuum leak will cause a lean code. you say you have original tb? what about the iac(clean cone and seat in tb.) what about the evap lines to the purge valve and fpr? check big boot to the tb for hardness/cracks/dry/rot.
theres a check for tps around here somewhere but that usually different symptoms that dont go away, always at a certain point in the throttle

https://www.gmforum.com/trouble-shoo...sensor-279319/

all the vacuum hoses,boots,etc are new but the throttle body is the original one.