ECUflash Evoscan logs IPS on '97 ECU, not '99

[Aphix]

I've been working on resolving this issue for a couple months now. I've talked to both Steve and Luv2Rallye who are experts on our ECU and the TPS adjustments necessary for our cars to properly function.

It seems that while in Evoscan with a '99 ecu, I am unable to log the IPS sensor. And when I say "log" I mean it is either a failure of the program with this particular ecu, or the ecu itself has some flaw that goes deeper than the basic circuitry.

The TPS:
All resistances verified and in range.
All voltages verified and in range.
Multiple TPSs have been tested.
The IPS DOES read in Evoscan 2.7 on a '97 ECU.
The IPS DOES NOT read in Evoscan 2.7 on the '99 ECU.

The '99 ECU has be reflashed, and the voltage divider circuit responsible for the IPS sensor in the ECU has been verified.

Obviously if this sensor isn't functioning it's wreaking havoc on the timing, ISCV adjustments, idle cutoff etc etc. What I'm wondering is if somebody has came across this issue with this ECU before, if I'm missing something ridiculously simple (it usually is something simple!), if I have some weird periphery bit messed up, anything! If anybody could shed light on this I'd really appreciate it.

 

[Broke4speed]

What is the MUT request for the 97 vs. the 99? According to Evoscan, it's 4A. All the MUT request lists I can find say that's EGR Purge duty cycle though. The possibility is that your switch is still working, but evoscan just isn't logging it.

4A could be the proper ID for pre-98 ECUs, but incorrect for post-98s.

Also, the 98+ cars may not even have an IPS. It may be based on TPS voltage.

http://forums.evolutionm.net/ecuflash/465942-idle-position-switch-off-evoscan-big-problem.html

 

[Aphix]

Thanks for the reply Broke4Speed, I read that thread and it does look like the 7/8/9 ECUs dont use IPS.

The only problem is I still am seeing my ISCV zero out at idle, and then go crazy through the throttle. I mean it ONLY moves from zero while I'm on the throttle.

Additionally, the EVO 5/6 would be the same ECU model-year as the 98/99 DSM ECU. And the voltage divider circuit is still fully functional in my 99 ECU.

So I could see the potential for not have an IPS switch since it is kind of redundant when we're measuring TPS; but then why is my ISCV trying to adjust while I'm in throttle.

The intake tract has had numerous BLTs and holds ~10 psi indefinitely, so no leaks, but it does seem to constantly have a high idle. I also get a lot of rumbling and sometimes a large backfire, which I suspect is linked to the decel fuel cutoff not functioning.

 

[Broke4speed]

If you look at the ISCV stepper table, you'll see that the ISCV is actually open under load. When I'm at WOT, my car is seeing 100 steps or more usually. I'm using a black box from an 02 mitsubishi in my car, so my tuning path is very similar to yours. I don't know why it's open under throttle, but everything is definitely working the way it should, and my AFRs are lining up perfectly.

If there was a flowchart/logic path available for the way these ecus think, it may clear up some confusion. I've been looking but haven't found anything concrete.

[edit] Ah, just checked out a 2G file in Ecuflash. The ISCV table does not have labels on it's axis. In the later Evo 8 files, it is, and it's Engine temp (horizontal axis) vs. Load (vertical). When you're at WOT, that's the base stepper position that the ecu applies all the multipliers to.

 

[MY1GDSM]

Can you post a log? With these Items logged? I'll see if I have some time later tonight and may be able (time permitting) to give some input on this...

 

[Aphix]

Broke4Speed, if 100 is the base setting then it explains my zeroing out at idle a lot better. I went ahead and readjusted the throttle bale set screw to 1 & 1/4 turns as I believe the manual states. I then put the car into idle speed adj mode and reset the biss screw to ~800 rpm.

MY1GDSM, thanks for offering to take a look at a log. I went ahead and set evoscan to all those items except WBO2 because that's the next priority. This is a 2nd gear pull I just did five minutes ago. I suspect my O2 sensor has recently kicked the bucket, it cycles and the heater circuit gets 12v, but I intended on picking up a WBO2 to remedy what I've suspected is incorrect A/F mix.