01 Silverado problem

[Jeffhaynes]

I have 01 Silverado 5.3 4x4. It sit for a year before I bought from family member. Only thing wrong then was alternator. I put new plugs, wires changed all fluids and fuel filter. Started right up but threw fuel pressure sensor and misfire code. Put new fuel pressure sensor and then had lean code and 0300 misfire. Fuel pressure was 52 with key on. 48 at idle and jump up to 56 when blip throttle. Cleaned maf sensor and no gas out of regulator vacuum. Any ideas?

[txab]

Look for unmetered air leaks on the intake side. Manifold gasket failure is not uncommon

[Jsdirt]

How's the fuel condition, after sitting all that time? Stale fuel will run lean and misfire, especially after ethanol separates out of it.

[Jeffhaynes]

There wasnt much fuel in it and I should have drained it but didnt and filled all way up with premium. And what's best way to find air leak in the intake. Thanks for the help, I'm not a mechanic and have been working on this thing for weeks 

[riverbanks]

48 is too low,it's running,but struggling

[Jsdirt]

6 hours ago, Jeffhaynes said:

There wasnt much fuel in it and I should have drained it but didnt and filled all way up with premium. And what's best way to find air leak in the intake. Thanks for the help, I'm not a mechanic and have been working on this thing for weeks 

Get a clean soda bottle, or a water bottle, drill a 1/4" hole or smaller in the cap, and use that to squirt water along the gasket area between the intake manifold and block. Do this first thing in the morning, after the truck is ice cold sitting all night. Any big air leaks you'll hear getting sucked in. For smaller ones, it's best to have a scan tool set up to watch your fuel trims and note any changes when water is squirted.  You'll hear a difference in the way the engine runs, too, when the water finds the leak.  On cold mornings, you'll also see more steam than usual coming out the tailpipe when water finds its way in. I used to use brake clean for this, but water is free, and works just as well - only difference is your fuel trims won't go rich when water is drawn in.

 

Remember:

 

-- A POSITIVE fuel trim number indicates the computer is ADDING fuel to correct a LEAN condition.

 

-- A NEGATIVE number indicates the computer is taking fuel away to correct for a RICH condition.

 

I highly recommend watching ScannerDanner (Paul Danner) on YouTube to learn how to find vacuum leaks. He's got some of the best content out there.

[Black02Silverado]

My thoughts.

 

I would change out the intake and valley cover gaskets.  It isn't hard to do and that way you know that is all taken care of.  As stated above they are common issues.

 

My 2002 didn't have any codes but was using oil.  Changed out the intake and valley cover gaskets and the oil consumption stopped and it seems to run way better with crisper throttle response

 

Also the fuel pumps on these don't last much past 100k it seems.  Changing that out is easy as well.  I pulled the bed off mine.  Not hard with an extra person to help lift it off.  

 

How many miles are on it?

[carkhz316]

X2 about Scanner Danner. It's because of him I've adopted the strategy of using water to find vacuum leaks instead of using carb spray or similar. It's quite effective IMO.

[Jeffhaynes]

Thanks for help guys. Truck has 136k on it. Riverbanks how much fuel pressure should I have? I read anywhere between 45-55.  And I'll be checking for intake leaks when I get off tonight 

[Jsdirt]

You'll want to at least be in the low 50's running. 53 psi and up.

[Jeffhaynes]

What would be looking for on losing that fuel pressure

[Black02Silverado]

1 minute ago, Jeffhaynes said:

What would be looking for on losing that fuel pressure

It is the fuel pump.  They are known to go bad and you are at about the correct mileage for it.  Mine was around that same mileage.

[Jeffhaynes]

Didnt hear any leak around intake. I'm gonna have someone come watch fuel trims as I try it again. The fuel pump was put on a little before it parked but I cant say for sure if it is right one or might be defective. Someone said could be a dirty or clogged injector? Anyone think that could be causing the problem. Also I forgot to mention it smells like raw or dirty fuel coming out exhaust 

[Black02Silverado]

Have you changed out the fuel filter?  It is right along the frame rail below the drivers side door. 

[Jeffhaynes]

I did change fuel filter and thought about changing again because I rushed and put it on with the little bit of gas and fuel treatment and ran it before I filled tank up with new