[Nimrod]

Hello, My 08 TB with 4.2 I 6 has recently been having a long crank / failed start. Try the 2nd time and it starts right up. With my code reader there are no codes or pending codes.
. Have about 150K miles on it and have followed factory maint schedule. I have not replaced the O2 sensors yet. I don't want to start replacing parts on a whim so asking if this is a common issue. Had the TB since new and it have been very reliable.
Thanks, Craig

 

[chem_man]

Well, the first thing I would do is to get a fuel pressure gauge and see what the fuel pressure is and how long the fuel injection system holds pressure after the engine is shut off. You could (emphasis on could) have a weak fuel pump. Normal fuel pressure should be at least 60 psi for your engine assuming you have the 4.2L I-6 engine.

 

[Nimrod]

Well, the first thing I would do is to get a fuel pressure gauge and see what the fuel pressure is and how long the fuel injection system holds pressure after the engine is shut off. You could (emphasis on could) have a weak fuel pump. Normal fuel pressure should be at least 60 psi for your engine assuming you have the 4.2L I-6 engine.

Thanks Chem man, got the loaner pressure tester as all I have is the one for non-fuel injection. Hooked up and had 0 psi. Turned switch on got 70 psi. Turned key off and it held at 60psi. If I start the engine it climbs to 70 psi and drops to 0 psi as soon as the engine is shut off. After trying a few times there is 0 pressure with the key in on position, only reads pressure with engine on. It only held fuel pressure the first test, dropped to 0 all other tests.

 

[Ravalli Surfer]

That quick pressure drop is not good. It likely is a bad check valve and that problem is unfortunate because it's in the fuel pump.

 

[Nimrod]

That quick pressure drop is not good. It likely is a bad check valve and that problem is unfortunate because it's in the fuel pump.

Thanks! Thought it was going that direction. The TB has been very dependable so can't complain of the occasional repair.

 

[chem_man]

As Ravalli Surfer said, it looks like the fuel pump to me as well. Also, 150,000 miles is not bad for a fuel pump. I used to say be sure and get either a Delphi or an ACDelco fuel pump, but I have been reading on other forums where Delphi's quality seems to be declining, so bite the bullet, cry once and get an ACDelco fuel pump and be done with it. By the way, rockauto sells the ACDelco/GM Genuine OEM pump for $165.89, and the Delphi pump sells for $284.79. (as an aside, Autozone sells the Delphi pump for $427.99 {YIKES!!!!} and the ACDelco pump for $256.99). WOW - one time the OEM part is less expensive than an aftermarket "equivalent to OEM" part.

 

[Nimrod]

As Ravalli Surfer said, it looks like the fuel pump to me as well. Also, 150,000 miles is not bad for a fuel pump. I used to say be sure and get either a Delphi or an ACDelco fuel pump, but I have been reading on other forums where Delphi's quality seems to be declining, so bite the bullet, cry once and get an ACDelco fuel pump and be done with it. By the way, rockauto sells the ACDelco/GM Genuine OEM pump for $165.89, and the Delphi pump sells for $284.79. (as an aside, Autozone sells the Delphi pump for $427.99 {YIKES!!!!} and the ACDelco pump for $256.99). WOW - one time the OEM part is less expensive than an aftermarket "equivalent to OEM" part.

Thank you for the help. I ordered the Delco from Rock auto last night. They usually have the best price and name brands.
Craig

 

[chem_man]

One of my favorite places to shop!

Good Luck!