Awful Vortec Running Issue

[G0053]

Apologies if this has been discussed as I could not find it. If there is a thread about it let me know!!

My wife’s truck has been having this odd running problem where it seems to be cutting out either the spark or fuel while under acceleration. I have a video of the issue while it is happening but I can’t seem to figure out how to attach it. Normally it happens in the morning right when you first start it and drive it. Doesn’t matter how long you let it warm up for. Later in the day on her way home from work it doesn’t seem to be happening (making this a little harder of an issue to pin down). It never throws an active code and there are no inactive codes either. It will just start misfiring and then it will start sort of backfiring and lurch really hard while it’s happening.

I have replace the spider injectors, the coil, the ICM, the Cap and the rotor so far all to no avail. I checked the fuel pressure while it’s having the issue and it stays steady the entire time. Not sure where to go from here, I’m at home tonight with a multi-meter and a load light, it seems to me it almost has to be electrical at this point. Any insight helps!!

 

[Cadillacmak]

You really need to start data logging your runs and finding the real problem. You might go in the wrong direction every time unless you know what is really happening. For instance, it could be the knock sensor picking up something external and retarding your spark. I had to run to town today for a meeting and used my wifes truck so I could log both ways, I can look at those latter as it still has some issues. I have HP Tuner and log with VCM scanner, but there are lots of others you can use.

 

[Komet]

Need a datalog. Feeling like a CPS issue but hard to say without catching it in the data.

 

[G0053]

You really need to start data logging your runs and finding the real problem. You might go in the wrong direction every time unless you know what is really happening. For instance, it could be the knock sensor picking up something external and retarding your spark. I had to run to town today for a meeting and used my wifes truck so I could log both ways, I can look at those latter as it still has some issues. I have HP Tuner and log with VCM scanner, but there are lots of others you can use.

I’ll look into VCM/HP Tuners and see if I can’t get ahold of a way to data log this. I work on heavy trucks and equipment on the daily and have simply just put off investing in good scan tools for obd2 because of it lol. So far my only saving grace with all of this is that everything I have replaced was not in good condition to start with. The cap and rotor were awfully corroded, the coil was weak when it was tested and I did the ICM just for the heck of it. The only reason I went into the spider injection is because I compared notes with a good friend and he had the exact same running issue on his blazer and that’s what it ended up being. In the meantime I am looking for very basic tests I can do to see if I can’t start narrowing this down to know where I should be looking upon data logging.

 

[G0053]

Need a datalog. Feeling like a CPS issue but hard to say without catching it in the data.

I was thinking this at first as well but was steered away from this idea from another mechanic that claimed they typically won’t even start if there’s any problem with the CPS. I didn’t really believe him, but I am very unfamiliar with these platforms.

 

[Komet]

I am looking for very basic tests I can do to see if I can’t start narrowing this down to know where I should be looking upon data logging.

That's not really how it works; you get the datalog first and whatever data is anomalous while the issue is being reproduced will likely give insight into the nature of the problem.

 

[Schurkey]

it seems to be cutting out either the spark or fuel while under acceleration... ...it happens in the morning right when you first start it and drive it... ...It never throws an active code and there are no inactive codes either. It will just start misfiring and then it will start sort of backfiring and lurch really hard

I have replace the spider injectors, the coil, the ICM, the Cap and the rotor so far all to no avail.

Spark plugs? Plug wires?

Did you replace the lower intake gaskets when the spider injectors were replaced? Did you use stock poppet injectors, or the newer electronic injectors?

I checked the fuel pressure while it’s having the issue and it stays steady the entire time.

Could still be an injector issue...but more likely ignition or sensor/computer.