Intermittent sputtering, major loss of power (No CEL)

[Lsxtrucker]

So I'm driving around town today and the grey ghost (My 2003 Silverado) is running fantastic. I go as the light changes green and the engine sputters, coughs, and I apply a bit more throttle to try to get her going and there is extreme loss of power. She just didn't want to go...but didn't stall.

Within seconds it clears up and does it again about 15 minutes later and returns back to normal operation again. No CEL now or at the time of these occurrences. 

 

Any tips on what this might be? It was quite scary in a bad way to have my truck lose power like that on the roadway. 

 

Thanks in advance! 

 

 

My truck is a 2003 LS, with the 4.8L.

[Lsxtrucker]

Update: I just pulled out of Wally world and the CEL started flashing.and the same loss of power occurs, there is very little power. Missing like crazy. I found a parking spot, and shut her down  Checked the wires (as I recently did plugs/wires) and they're all snug. It did  this three or so times before I changed the wires and plugs so that didn't start the issue. It started back up fine and I proceed to drive home. This is happening more than I feel comfortable with. Last thing I want is to pull out into traffic and for her to post  power and her get hit by another car  Any help is greatly appreciated, as always. Thanks 

[riverbanks]

Unplug the MAF,see if you have improvement

[Lsxtrucker]

2 minutes ago, riverbanks said:

Unplug the MAF,see if you have improvement

It'll run without it? I'm driving home and she's running fine no cell do have a new fuel filter should I swap that too? It's hard to diagnose when the CEL keeps going out and returns to running normal temporarily. 

[riverbanks]

Yes,it will run without it,better if it is the culprit,no change, fuel pump,more than likely

[Lsxtrucker]

2 hours ago, riverbanks said:

Yes,it will run without it,better if it is the culprit,no change, fuel pump,more than likely

So the fuel pump can cause a flashing CEL and misfire intermittently?

[riverbanks]

Yep,that's one reason why they give us a new pigtail with the pump module,old pump, working hard,taxing the wiring,stress, failure,domino effect,need pressure test,and scanner

[Lsxtrucker]

2 hours ago, riverbanks said:

Yep,that's one reason why they give us a new pigtail with the pump module,old pump, working hard,taxing the wiring,stress, failure,domino effect,need pressure test,and scanner

Thanks for replying. I ordered a fuel pressure test kit that someone linked me to on Amazon. I'll be sure to post my results once it's in. Picked up a scan tool too for the next time it throws a code. 

 

Is this the correct kit I need? Picture attached. 

[sefiroxx]

May also be clogged exhaust , collapsed converter internals or muffler.

[Lsxtrucker]

So the best way to diagnose this is to check fuel pressure, if normal then unplug MAF and look for improvement. If no improvement move onto the exhaust/cat and disconnect and check flow?

[Lsxtrucker]

I have been noticing quite a bit of radiating heat from under and around my truck hmm

[Lsxtrucker]

Threw a P0300 code this morning. 

[swathdiver]

Where in Florida are you?  You really need to get a bi-directional scan tool that can see and test everything so you're not guessing.

 

Tech-2 or a VXDIAG NANO on a laptop or tablet running Tech-2-WIN.

[Lsxtrucker]

51 minutes ago, swathdiver said:

Where in Florida are you?  You really need to get a bi-directional scan tool that can see and test everything so you're not guessing.

 

Tech-2 or a VXDIAG NANO on a laptop or tablet running Tech-2-WIN.

I'm in Sarasota just south of Bradenton. 

[Lsxtrucker]

She is throwing some major heat out from under the hood but engine temp is okay if this helps diagnose.