Excessive Cranking....

[BennyLumpkin]

So I did the search thing and saw a few things that were possible but I have an 02 V8 and I just did coils and plugs and VCG's....It did this before and still does. First time you start it for the day it fires right up but from then on it cranks for sometimes upwards of 15 to 20 seconds before it will start. Is it a crank sensor? I read about leaking injectors? Any help will be greatly appreciated. I have most of the bugs worked out now but this one is a real pain.

 

[joegr]

So I did the search thing and saw a few things that were possible but I have an 02 V8 and I just did coils and plugs and VCG's....It did this before and still does. First time you start it for the day it fires right up but from then on it cranks for sometimes upwards of 15 to 20 seconds before it will start. Is it a crank sensor? I read about leaking injectors? Any help will be greatly appreciated. I have most of the bugs worked out now but this one is a real pain.

I think the leaky injector(s) could be a good bet here. Do you ever see black smoke or smell gasoline when it is hard to start? Have you tried holding the gas pedal to the floor to start it?
Another good possibility is that your IAC may be starting to stick.

 

[Gus_Mahn]

I've seen Chevys do this. It was caused by a rupture in the fuel pressure regulator. It leaks fuel into the vacuum system and basically floods the car. If it sits long enough the fuel evaporates and the car starts almost normally. Pull the vacuum hose off the top of the regulator. If you smell or see gas replace the regulator.

 

[joegr]

I've seen Chevys do this. It was caused by a rupture in the fuel pressure regulator. It leaks fuel into the vacuum system and basically floods the car. If it sits long enough the fuel evaporates and the car starts almost normally. Pull the vacuum hose off the top of the regulator. If you smell or see gas replace the regulator.

The cars you saw this on had return type fuel systems. The LS has a returnless system. Fuel pressure is regulated be the PCM telling the REM how much power to give the fuel pump. There is a fuel pressure sensor on the fuel rail that also connects to manifold vacuum, but it doesn't have a diaphragm to rupture.