What would cause these values on a data log? See the two lines where the IAT is -40, I am having these intermittent shut downs that happen for mili-seconds while running. I believe these two lines are a capture of the issue.

 

I can hardly make out the column headings...

What's the sampling rate? I.e., how many milliseconds between each sample?

The issue is occuring much sooner (relatively speaking) than simply at the two lines with -40F on the MAT. Even in earlier data than what's shown on the screen, you can see the IAC count start to climb dramatically while the ECM is evidently trying to keep the engine alive.

You appear to be in open loop, so I'm not getting any clues from the INT or BLM. But the WB AFR doesn't seem to be going lean enough to cause an engine cut out (I'm seeing 14-15:1 which is close to stoich).

Other than that, yeah I can't read the column headings to know what the other columns are representing.

 

Looks like the TPS% goes to 0 momentarily, the O2mv drop to 0 and MAP kPa changes drastically from 80 to 0. Does TPS have “dead spot”?

 

Sorry for the crappy picture. Didn't know how to post just the one page of the data, so I took a picture of it. So to answer your questions, yes in open loop at idle. Sample rate is? 17 times a second? The ss heading stays the same # for 17 lines. Looking closer I now see the tps % climb dramatically and the rpm's fall. I don't believe I have touched the go pedal. This would indicate an issue with the tps sensor or wiring I suppose. Guess I need to look at that closer.

 

It is 17 frames of data per second.

The two lines with the -40* is the ECM doing a reset due to the engine stalling. The issue occurs prior to that happening.

To get a decent screen grab hold the ALT key down while hitting the Print Screen key. This copies the current (active) window to the Clipboard. Can then paste it into Paint or IrFanView and save it.

RBob.

 

Thanks Bob! Sometimes I can't see the trees due to the forest. So the question was asked of me what was the data collection rate? I don't see where you can change it. I do see where you can change the playback rate, but not data collection. Would you want to change the collection rate?
Anyway, I have been chasing this stalling issue for awhile, I suspected a loss of 12v on some circuit and have been chasing wires and connections. I never could catch the problem on a data collection, until now. Before it would stall and restart within milli-seconds. I replaced the TPS and went for a 10 mile drive without a problem!

 

You can't change the data rate, there is good reason for it to be at 17 frames per second. Has mostly to do with the internal loop frequencies that the ECM firmware runs at.

RBob.

 

I am aware this website is not here to promote your business, but if other companies would take note of your ability to converse with people who purchase their products but lack the same level of knowledge, man, my life would be so much more easier to get stuff to work right that I have spent my money on! You are the definition of customer service, as it should be! You are going to be doing this for at least another 20 years right? That would but me at 80 years old, and probably done with TPI.
MSD are you listening?

 

The reason I was asking about data collection rate was to get an idea of how much time was transpiring for the data I was seeing.

Need to get a better picture of the data though...

 

Looks like 17 lines per second is the rate of data collection, always. Thank You for your help and response to my question! Because of your reply I was able to re-evaluate the recorded data. I do believe I have solved my drawn out problem. Thanks again. Sorry for the crappy picture, now I know how to do it correctly next time.

 

How did these drop-outs manifest in terms of drivability at the time of occurrence?

Stuttering?... Low power?.... Momentary shutdown of motor?...

 

The issue actually happened mostly at idle, foot off the gas, engine would stall and recover within milli-seconds. At first I thought I was losing 12V power supply to the ECM, checked that, then ignition, then power to injectors, then ..... I was checking everything. I had not been able to catch it on a data log as it was very intermittent. I could drive for miles without a problem. Then I had other issues pop up, a EST fault, changed every ignition part, still there. Swapped ECM, fixed fault but I am not completely convinced it was the ECM, need to re-visit that at a future date. But the engine shut down issue was still there!
Just happened to catch it on a data log one day, the one I posted. I was focused on the -40 IAT reading and missed the TPS readings, until I looked again. So it appears the TPS at closed throttle would sense a almost WOT but the throttle had not moved, so it dumped a bunch of fuel in and killed the engine? But I don't see an increase in injector pulse? So unsure about that. Then went back to closed position and engine recovered. All happened within milli-seconds?
I have replaced the TPS and have not had another issue after driving for 50 miles now. Hopefully this is behind me. What a PITA!!!

 

SCHEEESh!!! You would think taking a screen shot and sending it to the clipboard would be a piece of cake! Well, it used to be! Windows 10 doesn't come with it installed! So downloaded the app, for free, but options for saving the info. are not in my realm of computer savvy. Trying to email it to myself, then save the attachment? This is crazy.

 

The results of the TPS going bad were just like you turned the ignition switch off then back on within half a second, without an exhaust backfire!