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MisfireMagnet

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About MisfireMagnet

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  1. The dealer said no it's out of warranty for time even though it only has 33,000 miles on it. I called GM and hopefully they will do something since if I had driven it a normal amount then it probably would have failed within the warranty period.
  2. Update: Took to dealer and they said the torque converter failed and destroyed the transmission along with it. They will attempt a repair or more than likely just replace entire thing.
  3. Yes, it will get to 6k rpm on the highway and the throttle position I have seen get to approximately 80%
  4. Okay, I got a reduced reading. There is a graph a few posts above yours that shows my absolute throttle position percentage engine-off but key-on and it goes from about 20-48% When driving the percentage does go up higher than that range.
  5. Nothing aftermarket, truck entirety stock. MAF cleaned and then replaced after strange temperature reading. Manual shifts fine but starting hesitation still present. Tow/haul doesn't have any effect, except higher rpm.
  6. Okay, so continuing down the path of the throttle position sensor. I recorded the following data while the truck was hot idling. I tried to push the pedal with my hand and hold it at the same position repeatedly. You can see the pedal position at each attempt stay relatively constant but the throttle position sensor dips right after pressing the pedal and then comes back up. I am thinking that maybe the TPS is bad. Going to look into how to test this sensor next.
  7. I have now moved on to checking the throttle position sensor. My scanner allows me to view Absolute Throttle Position (%) With engine-off key-on I went from not-pressed to pressed-to-floor several times and saw the below reading. Does anyone have the in-spec values for this?
  8. Also probably important to note is that when fully warmed up the hesitation is less noticeable or gone completely.
  9. Okay, so I have been recording every trip in my truck and stumbled across the following reading. My engine RPM read over 12,000 rpm for almost two seconds while I was driving steady at 1100 RPM. This happened several times but I zoomed in on one occurrence for clarity. You can also see my negative LTFT and maxing out STFT. At this point I would guess one of the following things is happening. My BlueDriver scanner malfunctioned several times. Crankshaft position sensor going bad. Camshaft position sensor going bad. Guess I will try to test bot
  10. I tested the evap purge valve on my workbench and I believe it is good. -held vacuum without leaking no power. -released immediately when power applied. I monitored my STFT and LTFT and they were negative with the evap hose connected. LTFT was around -15%. When I unplugged the hose and covered the port with my finger the STFT went to near zero and LTFT about -4% The truck was warmed up and the ambient temp is 80F. Does this seem strange? If so I guess the problem might be upstream of the evap purge hose towards the tank.
  11. After driving home from work the engine was hot and I restarted the truck to idle in the driveway. The evap purge valve was shut for about 20 seconds and then it started to make a popping noise and I could feel intermittent vacuum. Should this purge valve be open at hot idle?
  12. After noticing that both banks are roughly the same acting I believe it has to be something that must effect both sides. So ruled out, for the moment anyways, injectors, coils, plugs, and O2 sensors. Going to check evap purge valve to see if it has any vacuum on the port at idle. After that I might suspect one of the fuel pumps.
  13. Okay, so I have looked into fuel trims slightly and it seems they ideally should stay even with perfect air/fuel ratio. Since my STFT is maxing out at +25% that means the PCM is detecting a lean condition short term and is trying to add more fuel. However, my LTFT is consistently negative at 0 to -14% like the PCM is detecting a rich condition on average and is reducing fuel.
  14. Okay, so the truck ran great for two days and now the hesitation problem is back. I have taken some snapshots of the fuel trim readings over a time period where there is two hesitations present. I am going to have to do some research because I don't know what is good for fuel trims. Long term fuel trims against engine rpm here. Short term fuel trims against engine rpm here. Driving steps here. You can see as I start to accelerate from a stop the RPM increases to 1300ish for a split second and then falls to 600ish before jumping rapidly
  15. Thanks. I will log the fuel trims next and see if anything is strange. Codes are now listed as permanent and the truck will have to clear them when it determines the problem is gone. (according to my reader anyways) All fluids are at correct level.
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