Engine cranks but won't start

**cascade** · 08-14-2010, 06:15 PM

I've run into a bit of a problem with my fairly stock 2001 WS6. The only mods I have are a ported throttle body and an SLP lid. I had these on it for years prior to this problem arising. I drove it regularly when I was in high school, but moved across the country to California for college and left it home at my parents' house. A Ducati 1098 seemed much more useful for California given the traffic. While the car sat home on the east coast, I'd leave it up on a lift with a trickle charger and all fluids properly treated for long term storage. When I came home every Christmas and summer I would start it up and drive it around, and it never had a problem. Here's where the problem starts.

I came home for the summer a few days ago, filled the car with fluids, fired her up, and went for a drive. I decided to stop and grab some food, and when I came out and tried to start the car back up, it would crank and crank but not actually start. I tried starting it over and over, and it continued to simply crank and not start. I called my parents to try to come give me a jump, and as I was on the phone continuing to stubbornly try to start the car, it fired up as if nothing was wrong. Drove it home, pulled into the garage, and turned it off. Tried to start it immediately back up, and ran into the same problem...it cranks and cranks but doesn't start. After about ten minutes of turning the key, cranking it over for a few seconds, failing, removing the key, and repeating, the car started back up on a random attempt...fired up on the first crank of the attempt. For the past few days, anytime I want to use the car I have to go through ten minutes of trying before I get an attempt that works. Once it fires up, it runs perfectly. No hesitation or rough idle. No error messages on the dash. I have absolutely no idea what could be causing this, nor where to begin my troubleshooting. Any assistance would be GREATLY appreciated. Thanks in advance guys.

Update: Got a fuel pressure gauge and did the following:
1. Used screwdriver to relieve pressure on fuel rail
2. Unscrewed gas cap to relieve pressure, then put gas cap back on
3. Connected gauge to fuel rail
4. Turned key to on position but did not crank
5. Checked fuel pressure gauge

This gave me a reading of exactly 50psi. Does this help narrow down what's causing my car to crank but not start?

**KMdef9** · 08-14-2010, 06:39 PM

Can you here the fuel pump running?

**cammed goat** · 08-14-2010, 06:46 PM

^^That's what I am wondering as well. Or maybe the gas left in the lines gelled up and clogged the lines while the car sat?

**cascade** · 08-14-2010, 06:46 PM

Yep, when I turn the key to the on position but before I crank it, I can clearly hear the fuel pump whine as it primes.

**KMdef9** · 08-14-2010, 06:50 PM

Originally Posted by cammed goat

^^That's what I am wondering as well. Or maybe the gas left in the lines gelled up and clogged the lines while the car sat?

Could have clogged the filter as well.

**cammed goat** · 08-14-2010, 06:50 PM

Do you drain the fuel from the tank prior to storage? Or do you use a fuel stabilizer prior to storage?

**cammed goat** · 08-14-2010, 06:50 PM

Originally Posted by KMdef9

Could have clogged the filter as well.

**importhater81** · 08-14-2010, 07:56 PM

Check fuel pressure at the fuel rail.

**cascade** · 08-14-2010, 08:05 PM

Originally Posted by importhater81

Check fuel pressure at the fuel rail.

This was my first thought, but I couldn't find instructions on how to do so. Do I need a special tool to read the pressure at the fuel rail?

**KMdef9** · 08-14-2010, 08:38 PM

Originally Posted by cascade

This was my first thought, but I couldn't find instructions on how to do so. Do I need a special tool to read the pressure at the fuel rail?

Yes. They have it at most the auto parts stores, usually for free with a deposit.

**FBracing1222** · 08-14-2010, 08:58 PM

This exact thing happened to my buddys lt1. It turned out to be his ignition swithed it and started just fine.

**KMdef9** · 08-14-2010, 09:45 PM

Originally Posted by FBracing1222

This exact thing happened to my buddys lt1. It turned out to be his ignition swithed it and started just fine.

However, on an LS1, if the ignition switch is bad, you won't get any cranking.

**FBracing1222** · 08-15-2010, 01:35 AM

Well then learn something new everyday

**cascade** · 08-15-2010, 11:31 AM

Update: Got a fuel pressure gauge and did the following:
1. Used screwdriver to relieve pressure on fuel rail
2. Unscrewed gas cap to relieve pressure, then put gas cap back on
3. Connected gauge to fuel rail
4. Turned key to on position but did not crank
5. Checked fuel pressure gauge

This gave me a reading of exactly 50psi. Does this help narrow down what's causing my car to crank but not start?

**cpop98ws6** · 08-15-2010, 11:57 AM

Do you have spark when its cranking?? Maybe something is wrong with your securty system and is cutting off spark.

**KMdef9** · 08-15-2010, 12:03 PM

Originally Posted by cpop98ws6

Do you have spark when its cranking?? Maybe something is wrong with your securty system and is cutting off spark.

To my knowledge, the security system, when engaged, won't allow cranking.

To the OP, 50psi is good pressure, so is it starting when it has 50psi?

**cascade** · 08-15-2010, 12:10 PM

UPDATE:

Car is fixed. I switched the fuse from FAN2 with my IGN fuse, and voila....my car fired right up.

**KMdef9** · 08-15-2010, 12:11 PM

Originally Posted by cascade

Update: Got a fuel pressure gauge and did the following:
1. Used screwdriver to relieve pressure on fuel rail
2. Unscrewed gas cap to relieve pressure, then put gas cap back on
3. Connected gauge to fuel rail
4. Turned key to on position but did not crank
5. Checked fuel pressure gauge

This gave me a reading of exactly 50psi. Does this help narrow down what's causing my car to crank but not start?

I would normally like to point at spark plugs/ igintion coil, but since you say it starts up and will run fine after 10min of cranking, I'm starting to think sensors, if it isn't fuel pump/fuel line related. I don't think it would be injectors, b/c it would run intermittent frequently. Have you checked the fuel filter yet? At this point it wouldn't hurt to put some fuel system cleaner in the tank and run it for a while as well.

**KMdef9** · 08-15-2010, 12:12 PM

Originally Posted by cascade

UPDATE:

Car is fixed. I switched the fuse from FAN2 with my IGN fuse, and voila....my car fired right up.

Not enough amps?

**cascade** · 08-15-2010, 01:22 PM

Originally Posted by KMdef9

Not enough amps?

Appears the relay was starting to die. Replaced it with the one from the FAN2 slot, and it worked. Went to the store and bought a brand new relay and installed it, and the car continues to fire up the first try.