Cranking and no start

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Gmoney15

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I have an 2007 tahoe 5.3. Later it’s been cranking and starting but only sometimes. Usually seems when it’s hot. If I crank it and it just turns over then switch the ignition off then right back on it will fire up? I’m guessing maybe fuel pump?
The filter and regulator are all in the tank with the fuel pump I believe?
Or is there something else easier it may be?
Has 135,000 miles on
Thank guys
 

OR VietVet

Multnomah Falls
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Got to have 4 things to fire off the engine: compression, air, spark and fuel. Which of these do you not have when the problem occurs? Get a fuel pressure gauge on it and when turn the key just to ON, like it was in the crank position and then let go, see what the fuel pressure reads. Then watch that pressure while cranking. If runs, watch to see what the pressure is at idle and then snap the throttle to see what the pressure does. Then shut off and watch the pressure to see if bleeds off pressure.

Check spark: Use insulated pliers and hold the boot close to the spark plug tip and hope to see spark and what color. Can do the same thing at the other end of wire at the coil.

Does the cranking rhythm sound like normal? Is it slower than normal?

Post test results here.
 

Doubeleive

Wes
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fuel pressure is easy to check
with the key on, (engine not running) it should read 50-65, usually it's closer to the higher number
with engine running it should be minimum 43-44 or more.
you should check it when you are having the issue (while hot as reported) to verify if it is the fuel pump or not.
if pressure is good, then move on to other possibilities
you can also try turning the key on/off a few times while monitoring the pressure, usually this will help it build enough starting pressure and you can watch the gauge to see.
other indications of the fuel pump going bad is surging while driving or irregular idle, stalling out.
 
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