Mechanical_Moron

Hi. I joined a couple of minutes ago in hopes of getting pointed in the right direction. I had a couple of questions, not sure if they should be different threads.

1st question: my 5.3L 2004 Silverado started behaving oddly a couple of months ago. The symptoms are nearly identical to a dirtbike that has the choke on: obviously there is no choke, but that's the best way I can describe it. It idles "rough" and when I gas it, it nearly dies, then increases rpm's then cough coughs, increases rpm's cough coughs then gets up to speed. In addition, the service engine indicator light came on.

I figured it was watery gas so I kept driving it, assuming a few tanks later it would stop stuttering. It hasn't gotten worse, but it hasn't gotten better and its been six months. Irresponsible I know, but I'm a poor college kid and I don't have mechanic money or much know how. I took it to autozone to get a "free" diagnostic, but after refusing to be sold on the $85 diagnostic, the "free" diagnostic consisted of a pissed off mechanic resetting my codes and saying, "I told it wouldn't tell us anything."

So any suggestions a poor college kid can try? I'm not retarded, I'm a math/physics major at university, but I don't have much experience whatsoever in automotive mechanics. I dont' know anything, but to a newb like me, it seems like the fuel/air mixture is too rich or too lean. i'm not sure how to test this or even what could be causing it.

nauticstar87

Go to a different Autozone and try for codes again. the codes tend to say quite a bit. Although it may not be the direct problem it'll help.

Mechanical_Moron

The indicator light went away as soon as he hooked up the diagnostic thing. I assumed he reset it. Would another diagnostic computer still be able to read the codes?

MDTAHOE

It is most likely running too lean. There are 3 different main causes for that in these trucks ( there are others but are far less common). Low fuel pressure caused by a bad fuel pump, Low fuel volume caused by a clogged/restricted fuel filter ( by far the least expensive) or completely failed intake gaskets. If you have a couple of wrenches ( 16mm and 20mm or 2 adjustable) you can try the filter yourself for under $20.00, it is just ahead of the fuel tank on the drivers side frame rail.

Mechanical_Moron

Thanks man, that sounds like something I can try!!! I will give it a once over and let you know. Thanks!

desrtrat

04s and up the fuel filter is in tank. only way to service it is to remove pump from the tank..
on a cheep, try cleaning your TB and your MAF and run some sea foam injector cleaner in your tank..total cost about $20.

good luck

MDTAHOE

It maybe a very early 2004 and still have a filter. If it is in the tank then it is probably not your problem.

Mechanical_Moron

Oh noez, is there a way to diagnose this without pulling the fuel filter? I guess if the injector cleaner works then its the fuel filter?

desrtrat

put on a pressure gauge and see what kind of fuel pressure your get..

MDTAHOE

A fuel filter usually will not cause a drop in fuel pressure but will cause a loss of volume. It could sometimes cause a slight increase in pressure think of it like putting your thumb over the end of a garden hose.