Misfire under load no cel

[Texx1009]

2014 5.3 154k sudden misfire after hard acceleration.  1300-1700 rpm seems worse especially uphill.  No cel, doesn’t seem to misfire when in 4 cylinder.   Thought trans at first but definitely hear popping in exhaust.  Where should I begin with it without a cel?

[CamGTP]

A live data scan tool should be used to help diag the problem. One that can watch each cylinder in real time to see what is going on.

[shakenfake]

If it doesn't misfire in 4 cylinder mode I bet you are having AFM failure

[customboss]

8 hours ago, Texx1009 said:

2014 5.3 154k sudden misfire after hard acceleration.  1300-1700 rpm seems worse especially uphill.  No cel, doesn’t seem to misfire when in 4 cylinder.   Thought trans at first but definitely hear popping in exhaust.  Where should I begin with it without a cel?

Basic troubleshooting for spark, fire, and fuel.  Betting a coil has failed or corroded contact between wire/boot and coil/plug contact but not enough to MIL code throw. 

[Grumpy Bear]

On 5/2/2022 at 10:07 AM, CamGTP said:

A live data scan tool should be used to help diag the problem. One that can watch each cylinder in real time to see what is going on.

 

Oh boy is that a good idea, right? See below

 

On 5/2/2022 at 11:29 AM, customboss said:

Basic troubleshooting for spark, fire, and fuel.  Betting a coil has failed or corroded contact between wire/boot and coil/plug contact but not enough to MIL code throw. 

 

Yes but more than basic. Cam nailed it. Have to watch each cylinder one at a time. O-scope style. Know what happens if you don't?

 

Yea, ya replace allot to good parts trying to find the one bad one. Ask me how I know  

[customboss]

16 hours ago, Grumpy Bear said:

 

Oh boy is that a good idea, right? See below

 

 

Yes but more than basic. Cam nailed it. Have to watch each cylinder one at a time. O-scope style. Know what happens if you don't?

 

Yea, ya replace allot to good parts trying to find the one bad one. Ask me how I know  

Grumpy all your parts are wornout!!! LOL  

 

BUT DID YOU DIE????

Edited May 4, 2022 by customboss

[Grumpy Bear]

4 hours ago, customboss said:

Grumpy all your parts are wornout!!! LOL  

 

BUT DID YOU DIE????

 

Nope, harder to get rid of than that buddy. All good. I'm not stressing over it. Need better tools. Working on that.