97 chevy c 1500

[Bambam2806]

hi, i have a 97 chevy c1500 4.3 vortex v6 that was given to me. It had sat for about a year and a half before i picked it up. When i received it i put a new fuel pump and filter cleaned out the gas tank. It ran fine for 2 or 3 days and i drove 45 miles and it run fine. one day i drove it about 20 miles and it stalled, immediately when it started it would go then cut out again you couldn't go 50 ft without it losing power. The next day i changed the tps then cleaned the aic helped slightly but not much. Well come to find out my catalytic converter was blowing out honeycomb so we replaced it with a muffler since the real muffler had been cut (and no not directly under the truck we piped it out then put the muffler under the bed). It will idle but still wont run correctly i have heard there might be 2 fuel filters i will check that tomorrow. i will also ohm the 02 sensors to make sure the are working properly but they appear to be fine. Can anyone help me?

[1997SierraSLT]

I have a 97' GMC Sierra K1500 with the 5.7L and it's got an O2 sensor mounted on each catalytic converter. If yours is the same configuration on the 4.3L, then i suspect by changing out the cat with a muffler, you'd get inaccurate O2 readings at the ECM.

[cliobogger]

+1 about the O2.

[Bambam2806]

The one after the cat is only a code sender I checked it won't make it run differently I still have no clue.

[Dirtautoguy]

I had a similar problem on my 96 k1500 come to find out it was a $13 relay that was bad. Which made a bad connection which added up to wrong/no fuel pressure. And even now sometimes it rattles loose and runs funny I just have to push it back down and away I go.

[Dirtautoguy]

And the sensor after the cat doesn't change how it runs its supposed to measure how well the cats working. The two front ones change the fuel mixture. How is it at idle? Do you have any codes? Have you checked the dist. Cap wires and plugs? Or maybe a vacuum leak? Just some ideas let us know what you find good luck!

[Dirtautoguy]

O or maybe plugged fuel injectors.

[Bambam2806]

Ok I replaced that relay ill check to make sure it's pushed down. no in fact after I cut that o2 off the check engine light cut off and has not come back. I changed the distrib. Cap and rotor button that got it drive able it's still not right though, I changed the plugs also. I used sea foam and it blew out a tremendous amount of carbon when it did so right now I have no idea. After the sea foam it idled perfect.

[Bambam2806]

Bad news went for a drive this afternoon didn't even make it to the end of the driveway it's actin like it ain't getting fuel again...

[Dirtautoguy]

Hmmmmm injectors maybe?

[Bambam2806]

The sea foam should have taken care of that though.

[Dirtautoguy]

That's true. What about the fuel pressure regulator? Maybe have the fuel pressure tested and see how much pressure is getting there.

 

You could disconnect the engine side of the fuel filter and turn the key on then atleast you would know if its getting past there or not but it should e with the new filter. Does it still idle good?

 

Maybe a vacuum leak making it run really lean? Maybe take the air filter off and see if it helps.

 

Has the cel come back on?