hey guys, i have a 98' LT 4x4 . the other day i went to warm it up before heading off to work, would just turn and turn but wouldnt fire up.

about 3 weeks now it had been running rough but seemed to work itself out, the CEL would come on every so often and go out. i checked it for codes and i got a random misfire detection and a cylinder 4 misfire, changed the plugs and she seemed to do fine. well last saturday i was driving home when it started to bog down, almost dying when i put it to the floor, even got a backfire through the intake. babied it home turned it off, sat there for 5 minutes then started it, let it idle gave it a few revs and noticed a sound coming from the back everytime i revved it , like a chunk from the cat rolling around in the exhaust. turned it off tried to start it again, and here i am.

exhaust is coming out fo the tailpipe so i dont think its blocked up,i dont hear the pump prime itself, so thats my first guess. but i wanna make sure before i buy a fuel pump and turns out to not be the problem. anyone have some ideas?

 

I have heard if you smack the bottom of the tank with a rubber mallet that will get you to and from where you need to go. Have you checked the fuel pressure to make sure?

If you think it's the cat, pull the upstream O2 sensor and try to start it. DON'T RUN IT LIKE THAT. just see if it will run. If thats it then you can chop the cat out and weld a straight pipe in. I don't recommend gutting a cat because the insides are poisonous and your neighbor will hate you when their kids flunk out of school.

Check all fuses and relays as you would normally.

That's about all I can do. Hope this helps!

Regards,

Thomas

 

The cat is in this case never the problem. As You explained, there was a backfire. This means ; no gas!!! So, try this; on the drivers side on the inner wheel well there is a common + rail.(covered with a plastic cover) undo the 2 plastic nuts an take the cover off. There must be close to that "bar", a test wire hanging, to prime the gas pump without starting.Try to contact with the "bar" and hear if the pump reacts.(evt let someone hear in or under the car. If the pump starts and stops after a few seconds, it works. If there is NO sound. PUMP problems!!. If the pump works, there is another problem, f.e.fuel filter, tps( trottle position sensor)erg valve stuck etc., but try by logic elimination. If You have a "can "scanner try the direction of pinpointing by that.