LS V8 cranking issues!!!!!

my 00 ls v8 takes 2 to 3 attempts to crank. this is getting very irritating. before i start diagnosing has anyone else solved this problem and how. i've heard 2 theories(leaking injector) and low voltage. any suggestions????

There are numerous issues that could cause this type of slow start. You could have a leaking injector as you mention, but this would usually only cause an issue after sitting more than 15 minutes and less than 4 hours or so. Beyond that time, the leak would bleed off any pressure in the fuel rail and allow it to leak past the rings into the crankcase.

You could have low system voltage as you mention, have you checked the system voltage with a meter during the start attempt? What is the voltage?

You could also have low fuel pressure due to a weak fuel pump, faulty fuel pressure regulator, or abnormal fuel system restriction (such as a plugged fuel filter). Have you checked the fuel pressure at the fuel rail?

Bad spark plugs could lead to difficulty starting. How many miles are on the car, and have the plugs ever been changed?

An abnormal restriction in the exhaust could cause symptoms such as you describe, but are not very common.

You could have a vacuum leak as well, but that would often lead to a rough idle once the car does start.

An EGR valve that is stuck open could cause difficulty starting, but again you would most likely notice a rough idle once the car did start.

What condition is the air filter in? If it is restricted, it could cause issues.

Immediately after the car starts, what does the exhaust look/smell like? Is it dark and smell like there is a high concentration of raw fuel in it?

-Rod

well i just received this car from a relative and he has been away in the military for a year. during that time the car has been in storage and the battery was down. i'm wondering should i have the ecm flashed reason i say this is that i see that the ecm was flashed before back in 03 after he purchased it. i have'nt got around to checking fuel pressure but just last week i installed platinum plugs and valve cover gaskets(o rings) and i had a couple of oil soaked coils. i know i'm going to have to replace a couple of those cause the car has a little misfire now. as of codes the check engine light popped on and i scanned it and it showed code (420) low catalyst efficiency below threshold bank 1. so thats as far as i have gotten. i will check fuel pressure today!

well i'm back again found out some more things. ran diagnostic found out that cylinder #3 misfired a total of 19 times since last drive cycle. during last drive cycle the other 7 cylinders had 0 misfire. misfire will throw code 420 on ls v8 affecting the catalyst below threshold! far as my cranking issues checked that with otc fuel injection kit and cranking the car pressure holds around 52 to 55 psi which is good. the problem is when you cut the car off fuel pressure drops instantly which is not good because that car is suppose to hold fuel psi when you cut the car off. so this ls has no fuel pressure regulator that i can see and i called the dealer they told me that the pressure regulator is located on top of the fuel tank and you can't buy it without purchasing the entire tank whick runs $605.00! doing some more research i found that this car has a right fuel pump delivery and a left fuel pump jet transfer! i'm thinking that since the fuel rail is on the driver side which is the bleeder valve the jet transfer pump on the left would be considered the pressure regulator which delivers the fuel to and from the rail cranking and turning the car off! any help would be much appreciated !!!!!!!!!!!:banghead:

I would change the fuel pump. The pump itself has the check valve with it. Do not change the jet or transfer pump. All this does is transfer fuel inside the tank. The LS has a saddle shaped fuel tank and one pump can not completely empty the tank. It does NOT pump fuel to the engine. If your jet pump is bad you will run out of gas with about 1/2 a tank of gas or so.

The fuel pressure regulator (FPR) does NOT control how long the pressure remains in the fuel lines after the car is shut off. The LS has a electronic fuel pressure sensor and a return-less fuel system. So a conventional FPR is not used on the LS but the computer does know and will set a code if the fuel pressure is not correct.

Before you replace the pump do this. Before actually starting the car. Cycle the key on and off several times, pausing each time you turn it on for about 5 seconds. This will prime the fuel pressure to the max. Now start the car. If it lights off right away I would change the pump. If not then you might have a different set of problems?

Remember you do NOT have to drop the tank to change the pump. Either pump. Take out the rear seat bottom and there is a trap door for access. Finally Ford put this in!!!
.
.

thanks for the last post. i found out if i turn my ign switch to the on off position 5 times pausing 5 seconds in between each turn the car will start when i fully turn the key. so there we have it a weak fuel pump is the reason that my ls is difficult to start, and again thank you!