Won't start when it's really cold. The fuel pressure reads 55lbs initially upon priming, but it drops pretty quickly to zero. The fuel pump was replaced a few years ago because of the same problem. Is there some kind of anti-drain back somewhere that's causing the problem? The fuel pressure regulator was also replaced a few years ago. Any help would be appreciated. Truck has 60k on it and is daily driven. Thanks Michael
02 Silverado (5.3) cold start problems
- Thread starter turboclam
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no security light on display? if so,turn key on wait for security to turn off (from 2-10 minutes)...then start.....ive seen issues with the passkey2 sensor not reading correctally when cold... also the fuel pump ground; outside of the frame drivers side,before wheelwell under bed....check ground to be tight and clean...
I don't the keys have a chip. I know for a fact my 2003 with the 5.3 doesn't.
Which fuelpump did you go with? If you didn't go OEM I bet the anti-drain back valve went bad again. I have read where they go bad relatively quickly on the non-OEM fuel pumps.
Jason
Which fuelpump did you go with? If you didn't go OEM I bet the anti-drain back valve went bad again. I have read where they go bad relatively quickly on the non-OEM fuel pumps.
Jason
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Does the pump hmm loudly at all when running?
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The drain back valve is not critical. That would just make it take a second or two longer to fire but would not cause hard starting. Does the fuel pressure come up while cranking? Assuming it does, I would throw some new spark plugs and injector cleaner in. 
It's not hard to start, it just won't start. It turns over just fine. Fuel pressure stays up while the engine turns over. Let the key off and the FP drops to "0" pretty quickly. I'll check on the pump's loudness. He's got louder exhaust on the truck and is kind of hard to hear. Thanks!
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Exactly..
what my ap guy told me. In fact, he refused to sell me an aftrmkt unit. GM is the only pump he says will live.
He's had Airtex, NAPA, come back within a week...
what my ap guy told me. In fact, he refused to sell me an aftrmkt unit. GM is the only pump he says will live.
He's had Airtex, NAPA, come back within a week...
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no chips in the keys since the early 90's,i believe....the sensor is in the ign switch itself now.....
TexasT
Texas, Where are you from
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If it is loosing pressure that fast you have an issue.
I just went through a similar situation with the wife's DD. It put a new set of injectors in and now it starts with just a bump of the key.
Leaking injector or if there is some type of antidrain back valve on the pump it could be faulty. If there is a rubber section of fuel return you could clamp it off and try the key on to prime the pump and see if it holds pressure. If not probably a leaking injector.
I just went through a similar situation with the wife's DD. It put a new set of injectors in and now it starts with just a bump of the key.
Leaking injector or if there is some type of antidrain back valve on the pump it could be faulty. If there is a rubber section of fuel return you could clamp it off and try the key on to prime the pump and see if it holds pressure. If not probably a leaking injector.
Little6pack
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Clogged filter ????
usetaboost
SAY CAR RAMROD!!
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Whats psi when cranking? I wouldn't be surprised if you have a clogged filter or bad pump. If cranking pressure is good check the fuel filter to see if it is clogged. Don't ever use a fram fuel filter. I don't know about everyone else but I have had them clog every time I;ve used them and take out perfectly good pumps.
