Can someone help with what to replace next?
05-23-2008, 07:55 PM
#1
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Can someone help with what to replace next? My truck (2000 Silverado 5.3L) threw a misfire code this morning pulling into work.
Lately it's been starting hard (cranking for a good 5 seconds or so) before it catches fire. I've also noticed the idle is kind of rough. Here's what i've done so far:
Replaced the plugs.
Replaced the fuel filter.
Used fuel injector cleaner additive in the last 3 tanks.
The truck has been running rough and starting hard for a couple months, but today is the first time it's thrown a code.
The code was P0300. I have HPtuners and the O2 bank #2 isn't fluctuating anywhere near as much as bank #1. Bank #1 goes all the way from single digits to 9xx. Bank #2 might peak out at 400-500, but the waves are 3x as wide as bank #1. The long term B#2 was a heck of a lot different than the #1. (I want to say -9.3 vs almost 0 for bank #1) Also the timing advance is all over the place. It gets (a little) better as the truck warms up, but it seems like the motor is really struggling to keep a decent idle.
Do I have a bad O2 sensor? That's what i'm starting to think. While running the truck in my driveway to do the scan, I noticed what seemed like a raw fuel smell coming from the exhaust pipe.
Also, the truck has a propane dual curve system installed and it seems to run fine on propane. Other than that, the motor is stock.
I can run another scan and attach it to this thread if that will help you guys.
Any help is appreciated.
Matt
P.S. Truck has 58K miles.
Lately it's been starting hard (cranking for a good 5 seconds or so) before it catches fire. I've also noticed the idle is kind of rough. Here's what i've done so far:
Replaced the plugs.
Replaced the fuel filter.
Used fuel injector cleaner additive in the last 3 tanks.
The truck has been running rough and starting hard for a couple months, but today is the first time it's thrown a code.
The code was P0300. I have HPtuners and the O2 bank #2 isn't fluctuating anywhere near as much as bank #1. Bank #1 goes all the way from single digits to 9xx. Bank #2 might peak out at 400-500, but the waves are 3x as wide as bank #1. The long term B#2 was a heck of a lot different than the #1. (I want to say -9.3 vs almost 0 for bank #1) Also the timing advance is all over the place. It gets (a little) better as the truck warms up, but it seems like the motor is really struggling to keep a decent idle.
Do I have a bad O2 sensor? That's what i'm starting to think. While running the truck in my driveway to do the scan, I noticed what seemed like a raw fuel smell coming from the exhaust pipe.
Also, the truck has a propane dual curve system installed and it seems to run fine on propane. Other than that, the motor is stock.
I can run another scan and attach it to this thread if that will help you guys.
Any help is appreciated.
Matt
P.S. Truck has 58K miles.
05-24-2008, 11:17 PM
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sounds like a weak *** fuel pump, that would explain why it runs good with your propane
i work at a chevy dealership and fuel pumps on trucks like that go out bery often, hook up a fuel gauge and see if the pressure goes up to aroun 50 psi and also see if the pressure drops when the truck is shut off it should hold its pressure
i work at a chevy dealership and fuel pumps on trucks like that go out bery often, hook up a fuel gauge and see if the pressure goes up to aroun 50 psi and also see if the pressure drops when the truck is shut off it should hold its pressure
05-26-2008, 11:30 AM
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sounds like a weak *** fuel pump, that would explain why it runs good with your propane
i work at a chevy dealership and fuel pumps on trucks like that go out bery often, hook up a fuel gauge and see if the pressure goes up to aroun 50 psi and also see if the pressure drops when the truck is shut off it should hold its pressure
i work at a chevy dealership and fuel pumps on trucks like that go out bery often, hook up a fuel gauge and see if the pressure goes up to aroun 50 psi and also see if the pressure drops when the truck is shut off it should hold its pressure
Thanks for posting this, because I was looking at replacing the injectors next.
I will post an update after the fuel pump swap.
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05-31-2008, 06:45 PM
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sounds like a weak *** fuel pump, that would explain why it runs good with your propane
i work at a chevy dealership and fuel pumps on trucks like that go out bery often, hook up a fuel gauge and see if the pressure goes up to aroun 50 psi and also see if the pressure drops when the truck is shut off it should hold its pressure
i work at a chevy dealership and fuel pumps on trucks like that go out bery often, hook up a fuel gauge and see if the pressure goes up to aroun 50 psi and also see if the pressure drops when the truck is shut off it should hold its pressure
I swapped out the fuel pump last Monday and the starting and idling issues seem to have completely gone away.
Thanks guys.
