Long time frustrated quarterhorse/tunerpro user. lol! Having so many problems with datalogging on CDAN4, I understand it's a tuner/adx issue. The weirdest thing is that months back I hopped in the car after it sat for a month to try datalogging as a joke and it magically worked. Tried rebooting, messing with stuff to get it to "brick" (maxxing all dashboard values) but it worked great. Did a dyno day and found I needed to dial in my fueling further. Well the next day datalogging magically stopped working. Maxing values randomly. Well, got home from work and parked it. In the morning I hop in and the car is idling terribly. Key on and my fan is kicking on automatically. Knew instantly something is corrupted. Flashed my previous working tune, latest working tune, no go. Messing with the ECU harness/ECU and pulling it out slightly and magically after flashing again it's working fine.
Does the casing need grounding to the body? Is it possible it's a coincidence and bad QH battery? Is my datalogging issue possibly not an ADX issue but a "whatever with the ECU/harness" issue? For the life of me I cannot find a way to datalog via TunerPro for my setup whether paid or free unless I entirely switch software, which i'd like to keep with TunerPro. I'm going to fully pull my ECU out, pull QH, replace battery + wipe all contacts with some 99% iso + microfiber and reseat it to see if I see any differences.
One thing I noticed too is that while normal driving, holding RPMs cruising, it would randomly freak out for a quarter of a second and cut all power then cut right back on almost as if the MAF curve had a lower value as it increased. (e.g. if 2v was 25 and 2.2v was 20 it would freak out as it passed the cell)
This is driving me mentally insane.
Weird issues with ECU(?)
Moderators: robertisaar, dex
Re: Weird issues with ECU(?)
It sounds like you have electrical problem with the ECU and/or the QuarterHorse. Check the connections thoroughly. It may be worth opening up the ECU and checking for leaking capacitors (this can affect earlier ECU's but CDAN4 is getting old too now).
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tyler.h117
- Posts: 5
- Joined: Wed Apr 26, 2023 12:19 pm
Re: Weird issues with ECU(?)
I repair tech for a living, so I've taken the ECU + QH under a microscope to investigate it and using a multimeter to continuity test every single pin. Obviously some pins may be NC and won't pass the beep test, but I also ensured the pin wasn't covered in any kind of film or material and making solid connection. Forgot to check the voltage of the QH battery. Do you know off hand what caps people usually use to replace them with? Might replace them as a peace of mind down the road.