2008 Chevy Silverado 5.3L

[Dave S]

Been having trouble with the new Chevy starting. It seems to turn over for 5-10 seconds before it fires and starts. The problem is not as prevelent while burning E-85. It seems to be worse when there's regular unleaded in the tank.

Took it back to the dealer and they're at a loss on the situation. They want to hook it up to capture the diagnostics on it when this happens since we can't seem to repeat the situation at will at the dealership. They have a tester that plugs in that stays with the truck.

They've ruled out the fuel pressure regulator that seems to have been an issue with older Chevy's.

Anyone here have an idea what's going on? People don't spend that kind of money on a vehicle to spend time in the shop.

[Roofer]

It's normal............

Service Information

Document ID: 2001730 #03-06-03-001D: Starter Cranks After Key Is Released (Normal Condition) - (Aug 2, 2007)

Subject:Starter Cranks After Key Is Released (Normal Condition)

Models:2003-2008 Passenger Cars and Trucks (Including Saturn)

2003-2008 HUMMER H2, H3

2005-2008 Saab 9-7X

Attention: This bulletin ONLY applies to vehicles with PCM/ECM controlled starters.

This bulletin is being revised to update the models and model years. Please discard Corporate Bulletin Number 03-06-03-001C (Section 06 - Engine/Propulsion System).

Some customers may comment that the engine starter will continue to run after the key is released.

For the 2003 through 2008 model years, the Powertrain Control Module (PCM) or Engine Control Module (ECM) controls the starter relay based on input from the key switch. When the ignition switch is held in the start position for 0.4 seconds, the PCM/ECM start timer is activated. Once the start timer is activated, the PCM/ECM will continue to crank the starter until either the engine starts or a no start time limit is reached.

Occasionally, the fuel pump module will take one or two seconds to build fuel pressure. Often this will occur after the vehicle sits overnight. During some vehicle starts, the customer may release the ignition switch key before the engine actually starts. When this occurs, the engine will then continue to crank until the engine starts or the no start time limit is reached.

This is a normal condition and no repairs should be attempted for this condition.

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION

© 2008 General Motors Corporation. All rights reserved.

Most people notice it less with E85. The E85 pumps quicker than regular unleaded.

[Dave S]

Occasionally, the fuel pump module will take one or two seconds to build fuel pressure. Often this will occur after the vehicle sits overnight. During some vehicle starts, the customer may release the ignition switch key before the engine actually starts. When this occurs, the engine will then continue to crank until the engine starts or the no start time limit is reached.

The above info appears to be more relative to what's happening. When it finally does start, it does let out with a plume of smoke. It gets to be very disheartening that this is the way GM is designing vehicles now.

[fishin58]

The less technical advise- With a new vehicle that burns E85, the computer has to have time to analyze what it is actually burning. This simply states after a fill of a different fuel, you must allow 10 minutes or so of run time to get the computer reading the gas correctly. Just a thought, hope you get it figured out!

[Jeremy airjer W]

Many new vehicles will "start themselves". To find out start the vehicle as you normally would but instead of holding the key in the crank position until it starts let go of the key as soon as you hear the starter engages.

[Dave S]

I've done that. Do it all the time. The Toyota 4-Runner I traded also did it.

Even after burning a half tank, it will still do it on occassion. Not so often with E-85, but it did just the other day.

I'm heading up to Ely this afternoon. We'll see if it happens tomorrow morning when I head for home.

I'm believing the fuel system is leaking down and needs time to pressurize the system. The dealer said they'll replace the fuel pressure regulator and fuel pump if they need to.

If there's a delay in the motor firing over, I can mash the pedal to the floor and it will usually fire over then.