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Apps going bad? No codes

Alexio Auditore
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Ed ke6bnl

Ed ke6bnl

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I do not think it matters if it lags behind what you want to see nice round curves as you accelerate and deaccelerate and you do not want to see any sudden fall or rises clitches in the graph. I did this with a picoscope on  my toyota the flat top is where I held the throttle wide open. I was able to do this without the motor running by back probing the tps with the ignition on. 

tps.png

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Alexio Auditore

Alexio Auditore

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Ok. I still haven't found it then.

What I mean is the app doesn't have a tps section. It has a log portion where you can watch your speed, mass air flow rate, and then you can add a acell y and z. 

Unless I'm totally missing it, I haven't seen anything labeled tps. ( this is all through the app on android by the way)

 

That being said, I used this accel x and z, it does almost drop or flatten out when i hit those dead spots i talked about earlier.

 

Where is the tps monitoring part on the app?

 

I hope I'm not coming off rude, I'm just a bit lost with this thing, should be simple, maybe it is, I'm just slow:think:

 

Oh wait! Is it absolute throttle position in the logs section? Bingo I may have found it!

Edited by Alexio Auditore
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Alexio Auditore

Alexio Auditore

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Ok, this was my first trip of the day. This was me getting on the the freeway. The orange are my shift points. The red is the sudden almost lack of power I have been experiencing,  or dead spots I call it. It climbs like normal in rpm, then just slows way down, you can hear the turbo whistle less like I stopped pushing the go pedal. 

It wasn't bad today, tomorrow morning on my way to work I will test again, that is when it really acts up and is noticable.

 

I did the test with the truck off, and it climbs up all the way to 100 smoothly,  holds there, then drops when I let off of it. 

20180528_184850.jpg

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Mopar1973Man

Mopar1973Man

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Possible ECM. There is a state called limited pedal. What you'll see is the TPS is still commanding fuel but the ECM commanding the VP44 even less. You can see this in engine load. Engine load is equal to commanded fuel by the ECM.

 

So do the log again and add engine load with TPS so you can see both.

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Alexio Auditore

Alexio Auditore

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So the first picture was the worst I felt it. I left work and was going up hill from the job in first, I could feel the truck surge, even tho my foot hadn't moved.

The problem I see with this app is that the absolute position doesn't change as immediately as engine load. If I let off the pedal, the load drops immediately but it takes quite a bit longer for the absolute to register it has no throttle, not sure why.

The other thing I have seen is when the truck is hesitating or surging or whatever it's doing, both load and absolute drop, even though my foot hasnt let off the pedal at all, if anything I'm pushing a little more into it.

That's why I feel the apps is the issue, but it's just a guess.

Screenshot_20180530-153622.jpg

The second picture from the blue line forward is my crusing around 50, but you can audibly hear the load of the engine changing, and the same is seen with the absolute position, its fluctuating even though my foot is staying solid.

 

I did put it in cruise at another point, (not in included in the graph) the absolute position drops off and the engine load stayed consistent,  it wasn't giving me any problems then

20180530_164030.jpg

Edited by Alexio Auditore
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dripley

dripley

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 A while back I was experiencing some throttle surging for quite a while. Anywhere from 0 to 12% or so. Even got some APPS codes to go with it. Swapped in a new APPS and it did NOT solve the problem. Mine is working ok now though a few days ago it came back. I got it to stop by grabbing the wiring harness just outside the ECM and moved it what i could and squeezed as hard as I could and it stopped.

 The first time I did it and made it stop,with the surging described above, the problem renewed it self in the MAP sensor. Manipulating the harness stopped that also, just as it stopped the surging a few days ago. There is 5v sensor reference splice for the MAP and oil pressure sensor right in that area and just a little further away is a ground splice for most of the sensors. I cant help but believe that one of these is the source of my problem and maybe yours. I am not electronically versed enough to confirm that however. Mine on cruise would surge however.

 Hope that makes some sense. I feel @KATOOM disease coming on. Make sense to me but sure for anyone else.

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