Stumble during cruising. PL files (SD Chip)

[V8killR4U]

I have recently been experiencing some bad drivability issues. The car during normal cruising stumbles and bucks really bad. The issue seems to be random as I cannot duplicate the problem at a specific speed or RPM. The only factor that is the same is it only occurs while cruising. What I refer to as cruise mode is driving at a steady speed and TPS around .70 - .80 (no off and on throttle). A quick review of my PL files show the bucking and stumbling are result of erratic drops in O’2s. I have never experienced this issue before and have replaced the coil, ignition and ECM with known good one. I’m currently running a Red’s Double Pumper purchased New that is about 2 Years old now and running Turbo Tweaks SD (Mafless) chip. Also no codes are thrown while this stumble happens.
Can someone review my PL files and let me know what you think is the problem and what I can do to fix it. (You will see the erratic spikes in O2 voltage on the files and speed ranging from 40-60 MPH)

PL File 1 Frame 124-131
PL File 2 Frame 81-91
PL File 3 Frame 217-220 & 389-406

 

[Eric Stage I]

I don't see anything from any sensors, or anything in the tune that would cause that. Maybe something electrical is flaking out, like fuel pump relay, etc.
Eric

 

[Sweet6]

Do you have your laptop plugged into the Cigarette lighter while driving? Both of my cars miss and stumble when I have my laptop plugged into the Cig lighter. It must throw off the volts that the MAP is seeing.

 

[V8killR4U]

I don't see anything from any sensors, or anything in the tune that would cause that. Maybe something electrical is flaking out, like fuel pump relay, etc.
Eric

I couldnt spot anything either...so you suggect looking for potential electrical connection, grounds issues etc....

 

[V8killR4U]

Do you have your laptop plugged into the Cigarette lighter while driving? Both of my cars miss and stumble when I have my laptop plugged into the Cig lighter. It must throw off the volts that the MAP is seeing.

No laptop plugged in, running it off battery.....

 

[V8killR4U]

Any suggestions on what else could possibly be cause this. i hate to throw parts at it, but it sounds like i may have too :frown:

At 1st I was thinking possibly

Crank sensor
FP

 

[86GN-862+2]

My car was doing something similar and even backfired a couple of times at light throttle(cruising it). Turnes out the plugs wires were arching off intermittently. I had to check them on two separate nights because it was hard to see. Faint spark going across the wires. I put my hand right there and did not shock me but I bet it made a difference under load. Mine was a cheap fix. Hope yours is as as well.

 

[Pronto]

Years ago I had an issue like that on a Chevelle. Turned out I didn't hook up the ground from the battery cable to the fender. I'ld triple check your battery cables and grounds.:smile: