So it's been this way for a while, but recently seems to have become more noticable. I live off the freeway, so in the morning on my way to work, I am accelerating up the freeway on ramp, usually mildly, and it's like I hit dead spots in acceleration,  adding more go pedal will accelerate, but unless I romp into it more aggressively,  I'll hit those dead spots until I'm up to speed. Now I notice it even If the truck is warm and on flat ground from light to light. 

 

Other thing that may go with it ...

If I'm driving say 55-60 in fifth around 2k rpm and going slightly downhill,  I'll use the motor to slow me down, but I keep slight pressure on the pedal to keep at a steady speed(so that I'm not slowing down to much.) When it's in that between state I guess I'll call it, where its coasting or adding fuel, it's like it can't decide what to do, you can hear the motor start adding fuel and then not quickly alternating back and forth( it doesn't cause extreme bucking or anything like that, maybe slight, rpms don't change, its just doesn't sound right to me. My dad's truck doesn't do that, really no vehicle I've driven has. 

 

-My ac noise is .03.

-I've done a re-calibration before, it may have temporarily helped. 

-No codes thrown

-the truck has surged a few times very intermittently when cruise is set, it seems to do it when the ac is on?

 

I'm not super techy when it comes to electrical things either, I have a volt meter, but that doesn't mean I know how to use it lol

Any help is greatly appreciated. 

Wrong values that is G force. It's attempting to measure the G force X, Y, or Z directions. 

 

You what Throttle Position Sensor (TPS). 

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. 

You'll see the same thing numerically. You'll watch the TPS signal and slowly squeeze the throttle and watch the percentage of TPS from 0 to 100 percent. Watching for sudden changes or jump in the signal. 

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

 

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

Edited May 28, 20186 yr by Alexio Auditore

On the graph / logs section select one on the positions. Like I've selected the first one it will ask to select a PID. Do a search for Absolute throttle position. 

 

 

Edited May 28, 20186 yr by Mopar1973Man

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. 

Well I can tell you it's not the APPS sensor if it climbs smoothly. Even the graph you post doesn't drop to zero. For there to be lack off power you need to drop to zero.

If it's not the apps then what else might it be?

 

It doesn't zero out, but it's like it stops giving it the fuel I'm demanding from it. Kind of hard to explain

 

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.

Edited May 29, 20186 yr by Mopar1973Man

Will do, I'll post it tomorrow morning

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.

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

Edited May 30, 20186 yr by Alexio Auditore

Are you a manual transmission? Your 01 should have fly by wire cruise on a manual trans. When you set it the APPS is no longer in control. I believe the ECM is.

Yep, nv5600. I kinda figured that when I saw the throttle drop, but it makes me wonder if that means the apps is the problem

 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.

1 hour ago, dripley said:

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

Lol, I'm the same way, makes sense to me, but no one else.

I'll give that a try, I'm electronically challenged myself, but I'll see what I can do. Thank you

To me it looks like a failing ECM. APPS stay up where its suppose to but the engine load is dropping out so that is more ECM problem that APPS problem. Back to AC noise possible cause. 

8 hours ago, dripley said:

 I feel @KATOOM disease coming on.

 

Its called 'Chicken Syndrome'. Don't worry you don't have that.

 

I'm thinking bad/clogged tank vent. Try running with a loose fuel cap. Just a guess.

29 minutes ago, KATOOM said:

 

Do I have mixed up with someone else. I have CRD syndrome also.

3 hours ago, dripley said:

Do I have mixed up with someone else. I have CRD syndrome also.

 

Does your CRD stand for Chronic Respiratory Disease.....or Cant Remember D***?  Because I know I suffer from the second one.