5.3 not running on all cylinders?

**mikey82** · 03-09-2009, 10:46 PM

Hey guys I own a 2000 Silverado 5.3 when I pull out it seems as if the engine is not running on all cylinders- super hesintant to go. The truck will do this for a bit and then just like sombody kicked it it will take off. I replaced the plugs a while back and this did not help. Some times it will jump or lunge for a second and then take off. When I set at an idle I can rev the engine and it does fine. The only problem I have is on takeoff when the engine is cold. I thought maybe the plug wires dont really know any help is appreciated.

Mikey

**cascott325** · 03-09-2009, 11:00 PM

go and get your fuel pressure read. your regulator or pump may be going bad if it hasnt already. also you may need to change your fuel filter. make sure that when they test your fuel pressure, that they test while its started, and keep on testing after you turn the truck off. record the data given, and post back here so others can give their thoughts a whirl. have the pcm scanned too.

**mikey82** · 03-09-2009, 11:06 PM

Originally Posted by cascott325

go and get your fuel pressure read. your regulator or pump may be going bad if it hasnt already. also you may need to change your fuel filter. make sure that when they test your fuel pressure, that they test while its started, and keep on testing after you turn the truck off. record the data given, and post back here so others can give their thoughts a whirl. have the pcm scanned too.

So even if the truck runs fine once it gets going up hill included it could still be something concerning fuel pressure, Such as fuel pump or or fuel filter??

**silveradotrailblazer** · 03-09-2009, 11:12 PM

I would check or change the fuel filter. Why you have the fuel line disconnected check the fuel pressure between the fuel tank and filter. This will help you determan if the fuel pump is going bad.

**cascott325** · 03-09-2009, 11:15 PM

its possible. if you are not getting enough fuel, you wont have enough power. i have had a very similar problem due to a faulty fuel pump. the pump pumped, but the seals were broken, so it was pushing fuel past the seals and through the lines causing a decrease in power, response, and other things i cant realy recall at the time. you can also check your mass airflow sensor. check to see if there is any damage, if it is dirty or if the harness is connected well and not corroded. lack of air flow can cause the same thing.

**jlsparky7** · 03-10-2009, 05:27 PM

Im sure the other guys are right but heres a test you can do if you think the truck isnt running on all cylinders.

With the engine at idle pop the coils off the pack one at a time and listen for a difference in how the engine sounds. If there is a difference that coil is fine. If there isnt a difference then its that coil thats not firing.

**dwill3015** · 03-10-2009, 07:59 PM

X2 on the coil pack. I had the random misfire thing going on with my wife's 2001 Suburban w/5.3 and replaced the fuel filter, plugs, wires, and still had a miss to it and the random misfire code kept coming back. I ended up taking it to the dealer and they found a bad coil pack on #3 cylinder. Replaced and all has been great since! Also, while having it diagnosed at the dealer, they informed me of a recall on my Suburban for a fuel delivery issue and dropped the tank and installed a new fuel pump for free because of the recall.