Hard starting first time in the AM

[Todd B]

Hi everybody,

I have a 2015 Yukon with the 5.3 with approximaty 112k miles. Lately, its been slow to start after sitting for a few hours or overnight. The engine cranks just fine but it takes a bit before it fires up. This only happens after sitting for some time - like overnight. The rest of the time it starts right up. Ive also noticed the smell of gas outside the vehicle lately. Any ideas what could cause slow starting when cold?

 

[avalonandl]

The Direct injection motors may take longer to start as the high pressure pump may take longer to get up to pressure. The smell sounds like you have a check valve leaking.

 

[OR VietVet]

Welcome to the forum.

May have bleed down from a failing fuel pump when sits long enough. Best to do a fuel pressure test and watch to see what happens when shut off the engine. You sound like you do have a leak and that may be the culprit for long crank and fuel smell. Started happening at same time?

 

[Todd B]

Thanks.
I think the slow starting and fuel smell started at the same time. Any idea what it might cost to fix? I have an appointment with a mechanic next week.

 

[OR VietVet]

No way to know till you find out what the cause is. If you do the fuel pressure test and then shut off and it bleeds down quickly or slowly and with the fuel smell, it can likely be a line leak, o-ring leak, spout on top of fuel pump.....who knows. It may also not be safe to drive if it does in fact have an external leak. It may not even be at the pump. Could be in the lines from the pump to the front. Needs a thorough inspection from front to rear and a pressure test with the bleed down inspection. Do you have any CEL's?

 

[THarber]

Quick inspection to see if there are any fuel leaks under the hood There is a high pressure hose that connects to the fuel rails that might be leaking. Other than that, check the ground for drip marks and inspect or replace the fuel filter.

Tim

 

[OR VietVet]

Quick inspection to see if there are any fuel leaks under the hood There is a high pressure hose that connects to the fuel rails that might be leaking. Other than that, check the ground for drip marks and inspect or replace the fuel filter.

Tim

Hey, Tim, there is no exterior fuel filter for this rig. It is part of the fuel pump module in the fuel tank. I had an 02 LT and had the exterior fuel filter but my 05 Z71 has no exterior fuel filter

 

[THarber]

Gotcha. There has to be a leak somewhere, that's why you smell gas and why it takes a bit to start after sitting.

 

[Todd B]

No CEL is on. Not seeing any drips in yhe driveway other than the normal AC condensation.

 

[Todd B]

Update - the fuel line above the gas tank had a small hole worn thru it from rubbing on something. I guess GM addressed this issue with an updated fuel line design so hopefully it doesnt happen again.