2007 Yukon Long Crank when warm

[mmerr]

We recently picked up a 2007 Yukon SLT. We are having issues with a long crank (maybe 6 seconds) when warm. In the morning or after several hours of sitting, there is no issue.

I have already replaced the fuel pump with an Ac Delco unit. After replacing the sending unit, I sometimes get a faint gas smell.

After doing some research on the forum, I could not find anyone actually solving this issue.

Possible solutions seem to be.
-Coolant Temp Sensor
-Evap system solenoid or cannister
-Injector(s)
-ECM

I have the Torque Engine Management Diagnostics and tools app. Not sure if I can run any helpful diagnostic tests with this.

 

[wjburken]

Getting an understanding of where your fuel pressures are at in the different scenarios would be a good place to start.

Is your vehicle flex-fuel or not? That will determine what proper pressures should be.

Post that information up so the folks here can help you sort this out.

 

[mmerr]

Getting an understanding of where your fuel pressures are at in the different scenarios would be a good place to start.

Is your vehicle flex-fuel or not? That will determine what proper pressures should be.

Post that information up so the folks here can help you sort this out.

I have seen the Fuel pressure tests on the site. I will rent/buy the fuel pressure gauge and start there.

It is flex-fuel, which I have seen will typically have lower pressure.

Thank You

 

[Fless]

When you do your fuel pressure tests, do one on a cold engine and one when you expect the long crank time.

Key on, engine off. Document pressure, then document how long it takes for the pressure to leak down. For example, 8 psi in 15 seconds, etc., or 5 psi over 15 min.