My friends car will start sputtering and dying (I posted a thread a while ago), and we did some logging today, and I think we found the problem.

It looks like there is a fuel starvation happening right when it starts sputtering really bad, the o2 sensor reads zero volts, so it's leaning out really bad (no wide band), and the fuel injectors have the exact same value of 1.024 duty cycle until it starts running right again, at which point they jump back up to whatever the requested IDC is.

It's intermittent, and we're about to test the pump, but what else could it be?

Edit: Forgot to put up the log lol.

 

Anyone?

 

The oxygen should bounce all over, but zero, how can that be right?

 

0 volts should be signify that the car is going lean, but seeing as the OE sensor is narrow band, I have no idea how lean. I assume there is no fuel what so ever, or very very little, based off the constant IDC shown by the injectors. I also think the problem is pump related, as the injectors are still registering A value. I'm testing the pump next.

But who knows, I could be dead wrong lol.

EDIT: I just noticed it was pulse width that stopped fluctuating, maybe a problem with the injectors?

 

IDC will be non-zero because the IPW is non-zero. 1.024 ms is the lowest the IPW can go without completely turning off though, so something is wrong. Just glancing through your log, your MAP, and WGDC Correction both look off.

 

Whatever the problem is, it's a new development. The car ran fine just 3 weeks ago, then started doing the lean out stumble and die. It is currently tuned on speed density, stock turbo stock injectors, omni 4 bar.

And you're right, the load values are whacky. I'm not sure why they registered like that.

 

If its on SD, then my guess is the MAP sensor.

 

MAP sensor appears to be reading correctly. The O2 sensor is not cycling when it does that so it could be IPW dropout (though the "fix" has been done) or the O2 sensor is on the edge of failure (as evidenced in the low V right before it zeros).

A bad MAP sensor will cause the car to die and not restart or in that case just kill the car completely. The timing hasnt reset though so its not that but I am noticing that the TPS is also jumping all around. That is doing more in this case I think than anything.

Load is on the wrong channel. Why has the car not come down to us for free inspection and repair?

 

MAP sensor reads consistently good, and the injectors' reading is faulty before the o2 reads lean, so I'd assume the o2 sensor is reading correctly.

And the car hasn't gone down to ER because it's expensive to trailer or otherwise transport a non-driving vehicle 200 miles lol. Don't worry, it's not tune related.