97 K3500 7.4l spitting, sputtering, backfires, and stalls

[454cid]

I try to restarted bearly could keep it running. Let it cool down for an hour or so started ran rough than would run fine. Unplug it again ran good than would shut off that happen a couple of times

Hmm, I'm running out of ideas. I'd want to try to graph the sensor output somehow. I can do that on my Volvo with a specific app, but I've never tried getting a setup going for my truck. When you graph a sensors response in real time you can see if it's dropping out or shorting even momentarily. That's how I caught my faulty TPS in my Volvo.... it was shorting to 5 volts signalling WOT and making the transmission downshift, while just cruising down the road.

About the same as before

You haven't given that info before. You've given me bank 2, sensor 1 twice, but with different numbers. If one of those was actually the other bank then both sides are low..... so that would mean whatever is wrong is effecting both banks, which is helpful to know.

What codes are you getting? I'd expect you're getting a MAF code with it unplugged. What else?

 

[Agibson]

Now I'm getting a high voltage ignition control. That wasn't there earlier today

 

[454cid]

Any black smoke out the tailpipe?

 

[Agibson]

A little black smoke off an on usually when it starts running rough. O2b1S1 165 to 800

 

[Agibson]

SHRTFTB1S1 (%) O to 1.6
SHRTFTB1S2 N/A
SHRTFTB2S1 (%) -1.6 to 1.6
SHRTFTB2S2 (%) 99.2g
O2B1S1 (V) .060 TO 800g
O2B1S2 (V) .170 TO .175
O2B2S1 (V) .120 TO815
O2SB2S1 (V) .070
I just pull this right now. It's idling fine I give it a little gas and it stumbles and back fires.the O2 numbers do not change much when I raise the rpm

 

[454cid]

SHRTFTB1S1 (%) O to 1.6
SHRTFTB1S2 N/A
SHRTFTB2S1 (%) -1.6 to 1.6
SHRTFTB2S2 (%) 99.2g
O2B1S1 (V) .060 TO 800g
O2B1S2 (V) .170 TO .175
O2B2S1 (V) .120 TO815
O2SB2S1 (V) .070 (bank 2 sensor1?)
I just pull this right now. It's idling fine I give it a little gas and it stumbles and back fires.the O2 numbers do not change much when I raise the rpm

Can you verify the truck is in closed loop and staying there?

Also, are you sure you're typing the fuel trims right? You'll have short and long term for each bank, but not a sensor 1 and 2. Also the 99.2g makes no sense to me.... did you copy something besides fuel trim by accident?

Those o2 readings look better... it should oscillate between about .1 and .9 and it looks to be doing that.

 

[454cid]

A little black smoke off an on usually when it starts running rough. O2b1S1 165 to 800

Ok, that makes sense to me, because at those moments it's not burning all the fuel even if it's being fueled correctly for the sensor inputs.

 

[Agibson]

That is the numbers I'm pulling off the scanner. I double checked it before I posted. I could be reading something wrong I'm new to these kind of scanners

 

[454cid]

That is the numbers I'm pulling off the scanner. I double checked it before I posted. I could be reading something wrong I'm new to these kind of scanners

What scanner are you using?

 

[Agibson]

A earlier it would run for a minute or two just fine than die. When I went out to get more data it ran fine for about 5 minutes till I shut it but still stumble when giving it gas