i had codes coming up saying that all 4 of my o2 sensors were bad, i replaced them all and nothing.
it misses some, everytime that you hit the gas, it acts like it wants to cut off. i tried plugs, wires and still nothing? what do any of you think is wrong? i think i might have a fuel problem. also changed the fuel filter as well. anyway of checking the injectors?

10/31/2005 11:30:40 AM

does it smell like its running rich? how many miles on it?

i would bet money you need a fuel pump if it has never been replaced its fairly common on those

10/31/2005 11:32:47 AM

nah it ain't running rich, has 80k on it. i don't think it has had a fuel pump put on it. bought truck about 3 months ago. lemon, huh?

10/31/2005 11:37:33 AM

I dunno...check fuel pressure, go from there.

Anybody else had issues with Vortec injectors?

I know on the 4.3, it's a huge problem with the spider assembly.

The '97 uses individual ones, but I've seen a few replaced.

69 has a point about the fuel pump; common problem on ALL GM's.

10/31/2005 12:41:05 PM

egr system, codes often get thrown as o2 when egr valve or egr system parts go out

10/31/2005 1:13:47 PM

THANKS GUYS

10/31/2005 1:32:28 PM

the problem is that it is a chevy truck.... do yourself a favor and trade it for an f-150.... you'll thank me when you do

10/31/2005 7:39:26 PM

im a chevy guy, but in reality, the only thing he is going to trade it in for and not be a piece is a yota.

10/31/2005 8:02:43 PM

^ I agree

10/31/2005 8:08:16 PM

first, i wouldnt feel real comfortable making guesses on this without knowing the codes. second, if indeed the PCM was seeing 4 out of lean 02's, then you should have checked fuel pressure before doing anything. third, from your description EGR is definitely not your problem- that is obvious.


get me the exact codes and ill go from there.

10/31/2005 8:49:00 PM

definately dont keep driving it like that, but i was just thinking about it some more, and usually fuel pumps dont give much warning, they just kick the bucket, but still, a good place to start, otherwise the only thing i could think of would be the computer, if it has those particular runnability problems and is throwing incorrect codes

10/31/2005 10:02:59 PM

my friend has a superchips power programmer and i used the dignostics from it and it brought up 5 codes-- can't remember the exact numbers, but 4 codes were o2 sensor and the 5th code was multiple cylinder misfire.

10/31/2005 10:12:55 PM

certianly sounds like a low fuel pressure situation to me. test the fuel pressure, you can rent/borrow the tool from the auto parts store, and you should be able to look up the correct spec. online.

10/31/2005 10:17:56 PM

Or I can check your pressure for a few dolla. Just pick a nite when I am in the shop.

10/31/2005 10:31:56 PM

If you let completely off the throttle and then go back down on it does it act like it wants to run normal for a few seconds before acting up again?

11/1/2005 12:26:10 AM

IF YOU DRIVE IT LIKE YOU ARE DRIVING MISS DAISY, IT RUNS FINE, BUT AS SOON AS YOU GET IN THE THROTTLE, IT MISSES, AND DOESN'T GO ANY FASTER.

11/1/2005 7:17:30 AM

def sounds like a fuel pump then, but if it has the correct pressure, then probably water in the gas, not much else you can figure out till you hook a gauge to it

11/1/2005 12:37:25 PM

11/1/2005 1:23:16 PM

yea, i just bought one so i can check. anyone know have the top of their heads what the pressure should be?

11/1/2005 1:39:43 PM

I dunno what the Vortec systems run...somewhere between 45 and 60?

11/1/2005 3:27:22 PM

static, cranking or running pressure? you also need to watch how fast it goes up, should be less than a second

^somewhere in that range, it should run fine on anything above 40

11/1/2005 9:40:35 PM

THANKS

11/2/2005 7:13:09 AM

69- is the winner. water in gas; dropped the tank and had near bout 6 gallons of water in it. hate to think that i was paying close to $3/gal for water. STAY AWAY FROM ALL DUCK THRU GAS STATIONS! problem is fixed and is running smooth. thanks 69!

11/16/2005 9:49:25 PM

good thread good thread

11/16/2005 9:59:32 PM

damn, i was right about something for once, my random shit i throw out there is awesome, too bad it took two weeks for someone to listen to me though

11/20/2005 3:13:01 PM

nah, it took a few days b/c i had to work. i was going through my topics and decided to post the results. thanks 69

11/23/2005 8:58:35 AM