5.7 Vortec intermittent long crank --> crank no start, backfires, clunking

[GMTMark]

I had a similar problem with a 1997 Suburban. That was the fuel pump. If you’ve replaced the regulator then I recommend replacing the fuel pump. I don’t like throwing parts at a problem but that’s what I would do.

 

[Tomcat71]

change the pump. its leaking past the internal check valve, had the same issue with my ex wifes S10.

 

[slow_c1500]

Same exact issue? Where it starts fine overnight or less than 15ish minutes?

Ill still take the upper intake off to inspect injectors/regulator to be totally sure (i can get it apart in 15 min lol), and if they are fine, I will be convinced that its the fuel pump.

 

[slow_c1500]

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Newbie question, but if my check valve did happen to be leaking, would I replace just the cylinder-looking thing that I circled? Or that entire pump assembly?

Anything else I should think about replacing while I would be in there?

 

[Schurkey]

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Newbie question, but if my check valve did happen to be leaking, would I replace just the cylinder-looking thing that I circled?

The "cylinder-looking thing" IS the fuel pump. The rest of it is just support structure.

Anything else I should think about replacing while I would be in there?

Filter sock that goes on the bottom of the pump, and the wire harness.

However, you have the option to replace the entire unit.

 

[slow_c1500]

Got it. Ive heard that Walbro (as long as its not counterfeited) makes good fuel pumps for these trucks. Does anyone know what Walbro pumps fit a 5.7 vortec? Btw the motor is stock, so I don't need crazy fuel pressure.

 

[docstoy]

Looking at your pic, the wiring going to fuel pump looks to have been overheated, is that just optical illusion because of where it is ?

 

[slow_c1500]

Looking at your pic, the wiring going to fuel pump looks to have been overheated, is that just optical illusion because of where it is ?

Thats a screenshot from a video, not mine

 

[slow_c1500]

hey guys, I pulled the upper intake today to confirm for sure that my fairly new spider/reg aren’t leaking. They are not. After doing this, it would crank but not start at all. Truck is getting adequate fuel pressure and I can hear the pump whine for 2 sec when key is on. Is it possible still that the fuel pump is my problem? Or something else?

 

[slow_c1500]

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My cap and roto look like this. Is it normal, and if not, could this cause a crank no start?