I have a 2002 v8 lse with 92000. When i go to start it after it has been sitting for 20 minutes or more it cranks for a long tome before starting. When it does start it idles fine but has a strong fuel smell. There are no codes and no problems once it starts. However it starts up right away in cold weather. It seems like a flooding issue. The fuel pressure is within range but it does seem to bleed off quicker than most cars i work on when the engine is no longer running.. Unfortunately i dont have the specs on on fuel pressure runoff. I suspect the fuel pressure sensor/regulator. I dont believe it would be an injector due to the fact it never runs rough or misses once started and if it was the pump it wouldn,t give off a fuel smell in the exhaust once started. I was wondering if anyone has seen these sensors go bad or if there is another common problem with these vehicles. Thank you for your time.

Sounds like a BAD MAF sensor!
The MAF Heats the volume of Air,the Incoming Air Temp is measured,and
a signal is sent to The PCU for Air/Fuel control.

When you jump on the Gas pedal,is the car a little slow to react?

Wide open Throttle = Colder Air,the IACT sensor drops more voltage going to the PCU.
Closed throttle = Warmer Air,the IACT sensor drops less voltage going to the PCU.

Rob has a very good point!
Fuel filter,Air Filter,Air Box,and throttle body cleaning.
MAF sensor cleaner can be bought @ local parts store.



MCGHIVER

The MAF doesn't actually heat the incoming air. On hot wire MAF sensors there is a reference sensor element that is heated and the temperature rate of change of that element as the incoming air passes over it is used in the calculations, but the intent is not that it heats the air.

I've not yet replaced the fuel pressure sensor on my wife's 2002 LS V6, but at one point I suspected it as faulty due to a long crank and intermittant stalling issue. However, once I replaced the battery, that issue went away.

In addition to cleaning the MAF, you might consider cleaning the throttle body as well. When's the last time the fuel filter was changed? You may as well start with some typical tune up items, and check the age of the battery. If it is nearing 5 years of age, consider replacing it before tearing into the diagnostics too far.

-Rod

The car does not stuutter when I get on the gas. It accels right away. It has a new battery and I an replacing the fuel filter today. I will clean out the throttle body today and the maf sensor. The reason I thought it was the pressure sensor is that when I disconnect the vacuum line from it to the intake it has fuel vapors in it and slight fuel deposits. Thanks for the input.

The car does not stuutter when I get on the gas. It accels right away. It has a new battery and I an replacing the fuel filter today. I will clean out the throttle body today and the maf sensor. The reason I thought it was the pressure sensor is that when I disconnect the vacuum line from it to the intake it has fuel vapors in it and slight fuel deposits. Thanks for the input.

May have a regulator problem if fuel is getting into the vacuum line.

AD:grinno:

May have a regulator problem if fuel is getting into the vacuum line.

AD:grinno:

I assume that you have never worked on an LS? It doesn't have a return flow fuel system. Fuel pressure is regulated electronically. It does have a fuel pressure sensor that measures fuel pressure related to manifold pressure, so a leak from the fuel line to the manifold is possible, but it is very unlikely.