Truck wont start suddenly

[yukon06]

Hi guys..
2006 yukon ran fine until it doesnt.
No issues yesterday, got home and parked. Today I go to leave and it cranks but wont start. Battery is strong and it has gas in it.
I dont have many tools or testers left since im disabled but i cant imagine this being a huge deal, though i have no clue where to look for the problem.
Can anyone help me out with any similar situation or any guidance at all......
Thanks

 

[strutaeng]

Fuel pressure gauge and test for spark would be the first two things to test.

Hopefully you have the tools for that. If not, they are not that expensive if you can get to the local parts store or maybe you can borrow some from a neighbor or friend. I think you can substitute a test light for a spark tester(?), if that's an option.

If nothing is at hand, press the Schrader valve to see if you have "some" fuel pressure buildup...just careful with fuel spills...

 

[yukon06]

Thank you.
I unscrewed the gas cap already thinking maybe a vapor lock or something and i dont know even if it did by unscrewing and then putting back the gas cap would help but i did it and no help.

I just watched a video on the valve you mention so i will go out there and do that now. What should happen when i press it? From the video i just watched i should get a little bit of fuel out? Then try and start?

 

[strutaeng]

Thank you.
I unscrewed the gas cap already thinking maybe a vapor lock or something and i dont know even if it did by unscrewing and then putting back the gas cap would help but i did it and no help.

I just watched a video on the valve you mention so i will go out there and do that now. What should happen when i press it? From the video i just watched i should get a little bit of fuel out? Then try and start?

Depending on if the fuel system is primed, you will get a good squirt of fuel... that's why you need to be careful. Have a rag ready.

Not the proper way to check for fuel pressure of course, but it's better than nothing.

 

[yukon06]

Strutaeng!!!!
THANK YOU BROTHER.
I released the pressure by pressing in the schraeder valve and she came to life. All is good at the moment but if you have time teach this man to fish a little and explain to me what happened and why releasing the pressure worked and if this will be ongoing that i have to do periodically?
I will also research this tonight.
Thank you again bud......enjoy your weekend

 

[89Suburban]

Beat the bottom of the fuel tank with your fist and see it it starts.

 

[strutaeng]

Strutaeng!!!!
THANK YOU BROTHER.
I released the pressure by pressing in the schraeder valve and she came to life. All is good at the moment but if you have time teach this man to fish a little and explain to me what happened and why releasing the pressure worked and if this will be ongoing that i have to do periodically?
I will also research this tonight.
Thank you again bud......enjoy your weekend

Wait, what!

The fuel system NEEDS to be pressurized!

Not sure what happened there... maybe an intermittently failing fuel pump? Sometimes the fuel commutators inside the pump motor start going out, and beating the tank or whatever brings them back to life (as @89Suburban was aluding to), but it's bound to happen again...

Better get yourself a fuel pressure gauge to have handy.

 

[yukon06]

Wait, what!

The fuel system NEEDS to be pressurized!

Not sure what happened there... maybe an intermittently failing fuel pump? Sometimes the fuel commutators inside the pump motor start going out, and beating the tank or whatever brings them back to life (as @89Suburban was aluding to), but it's bound to happen again...

Better get yourself a fuel pressure gauge to have handy.

Shit...not what i was hoping to hear.
So driving this truck now is unreliable until fuel pump is replaced or i guess youre saying check it with a fuel gauge first.
Ill have to look for the most inexpensive one on amazon that actually works.
Do youknow what i should see when i connect it?

Also is replacing the fuel pump a hassle?

 

[strutaeng]

Shit...not what i was hoping to hear.
So driving this truck now is unreliable until fuel pump is replaced or i guess youre saying check it with a fuel gauge first.
Ill have to look for the most inexpensive one on amazon that actually works.
Do youknow what i should see when i connect it?

Also is replacing the fuel pump a hassle?

Can't say it's the fuel pump until you check the pressure. Even if you suspect the fuel pump, electrical like fuses and wires/grounds would be the next steps... sanitary checks, you know.

Fuel pressure should be around 52-54 psi "ish" with key on, engine off, it depends on engine. Someone may post a spec on actual required minimum pressures...Pressure should also hold steadily for a few minutes.

I will admit that I have never replaced a fuel pump myself, but you have to drop the tank, so yes, it's a big deal.

I will tell you this though: fuel pressure gauge has saved me several times from chasing suspected fuel delivery problems. For example, on my 99 Silverado with the 4.3 I had a persistent crank-no-fire. Fuel pressure always checked okay. I discovered that it was related to damp/rainy conditions. I eventually swapped the engine to a 5.3 and my the fuel pump on that truck is still the original. I'm currently at 270k.

 

[OR VietVet]

Gas or flex fuel different pumps and pressures, but not by much. Just relieving pressure at that valve did not fix anything. You could have just as easily kicked a tire and the same thing happened and started. You may have intermittent no spark and it chose right then to have spark. You need 4 things to start an engine. Fuel, spark, compression and timing/air. You were missing one of those at that particular time.