Ecotec 5.3 long crank when cold - replace fuel pump now?

[avacado11]

got rid of my F150 and picked up a 2014 Silverado 5.3 ecotec. 150k miles but beautiful rust free body. Mechanically it’s running great. Direct injected motor.

First cold start in the morning it’ll long crank(1-2 seconds before firing up). If I cycle the key once and let the fuel pump prime(I can hear it in the tank) it’ll fire up immediately. Some people are saying this is normal for the 5.3 ecotec due to it being direct injected.

I was thinking of replacing the fuel pump as I don’t want to be stranded. Do I just replace the low pressure tank pump or does the high pressure on the engine side need replacing too?

 

[Jetronic]

if cycling the ignition solves it, it's not a high pressure pump issue (at least not with building pressure). But you could have a fuel leak from injectors or inside the fuel pump. much fuel in the oil?

 

[JavierH19]

If it fires up immediately right after being shut off then it's very likely the check valve but I'm not sure if it's replaceable on its own. On the old trucks they had a diaphragm under the hood where if it'd rupture it'd make it crank like 7 seconds but after starting I could shut it off and it'd turn it back like normal if I didn't let it sit for more than a few seconds. But those old systems were a return type the ones after are return less and don't have the diaphragm anymore just a check valve.

If you do get a fuel pump only use oem or oem grade. Ac delco is oem but they've had stuff made by denso, delphi, bosch and likely others and those are also oe suppliers for other brands.

 

[avacado11]

if cycling the ignition solves it, it's not a high pressure pump issue (at least not with building pressure). But you could have a fuel leak from injectors or inside the fuel pump. much fuel in the oil?

No fuel in oil at all. I get a feeling the anti drain back valve in the fuel pump is bad. Wasn’t sure if it’s worth replacing soon or if a worn check valve can be left alone as long as the pump works

 

[avacado11]

If it fires up immediately right after being shut off then it's very likely the check valve but I'm not sure if it's replaceable on its own. On the old trucks they had a diaphragm under the hood where if it'd rupture it'd make it crank like 7 seconds but after starting I could shut it off and it'd turn it back like normal if I didn't let it sit for more than a few seconds. But those old systems were a return type the ones after are return less and don't have the diaphragm anymore just a check valve.

If you do get a fuel pump only use oem or oem grade. Ac delco is oem but they've had stuff made by denso, delphi, bosch and likely others and those are also oe suppliers for other brands.

Check valve is built into the fuel pump so if I do it I’ll be dropping the tank. One thing I learned with my F150 is stuff like fuel pumps it’s worth it to buy OEM. The pump always likes to go on a full tank, at the worse time possible. Had a Delphi pump go bad on me ended up buying OEM. Did the job twice only to save like $120 the first time around.

 

[Jetronic]

the in tank fuel pump should have a check valve aswell. could just be the low pressure circuit that's draining. You can't read that on obd, but you can read the high pressure side. so if that maintains pressure, it's the low pressure pump.