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ECMlink The mistake I made before tuning

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techtx

Probationary Member
3
0
Jun 30, 2019
Humble, Texas
I just recently got my car back from a tuner. It runs great at WOT and cruising but was never the best at idling. Sometimes when the rpms drop to idle the vehicle would stall. This became more and more common as the weeks have gone by. In my attempts to diagnose the issue I think the culprit is that I had an old autometer air fuel ratio gauge still running off the O2 sensor pin. This auto meter air fuel ratio gauge was installed years ago and was running off the narrowband O2 sensor. Just before I sent the vehicle to the tuner I installed the LC2 wideband sensor in place of the original O2 sensor. I installed the innovate wide band gauge as well not thinking it would matter if I removed the old autometer AFR gauge. I believe the old autometer gauge is affecting the actual readings from the wideband O2 sensor to the ECU and my tuner compensated for the readings and still was able to tune the vehicle. I understand this is completely 100% my issue and I am not blaming anyone else but myself.


So here I my actual dilemma. With the old gauge installed, the car will actually run nicely except for the idle. When I disconnect the old AFR gauge and recalibrate the O2 sensor before running. The wideband signal will cycle around 13.0, it never comes out of open loop and will not simulate a front O2 sensor signal (front 02 voltage will stay pegged at 0.8V). I can then plug in the old autometer AFR gauge recalibrate the wideband O2 and the car will go back to cycling around 14.7 AFR, drop into closed loop at idle and will simulate a cycling narrowband signal for the front O2 (0.2V to 0.8V).


I am attaching 3 logs. The first is the log with both the autometer AFR gauge and innovate AFR gauge installed (the way it was tuned). AFR gauge was cycling around 14.7 and I took a trip out of the neighborhood and did a 2nd and 3rd gear pull. When I made the uturn the engine stalled when coming to a stop and that’s the end of the log. The 2nd log was started just after that, I started the car and it attempted to idle but immediately stalled. The 3rd log is with only the innovate AFR gauge installed, O2 sensor recalibrated and just idling in the garage.


I understand its just as easy to take the car back to the tuner and start all over again. And I will, but this is technically just my engine break in tune. After I put a thousand miles or so on the engine I’ll be taking it back. In the mean time is my issue something that I can fix relatively easily so I can continue breaking in the engine.

I’m sure there is information I am forgetting. Please don’t hesitate to ask. Or maybe i'm over thinking the whole thing...


Thanks in advance for the help.
 

Attachments

  • #1 stall.elg
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  • #2 stall again.elg
    14.3 KB · Views: 111
  • #3 gauge disconnected.elg
    100.3 KB · Views: 108
  • gauges.jpg
    gauges.jpg
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How are you hooking up the LC2? are you hooking up the wide band wire or narrow band wire to the ecu? if the gauge is a narrow band and the LC2 is being wired for Wide band it will not run right due to the outputs. Narrow band is 0-1v wide band is 0-5v.
 
I didn't think there was a narrowband wire from the lc2. I wired in the lc2 just as directions said to. Yellow wire to pin 4 on the ECU. Then changed the pin assignment in ecmlink to lc1 for the front o2 sensor and simulate a narrowband signal. Yes, the old auto meter gauge was intended to be used for a narrowband signal. It currently stays pegged full rich once the o2 sensor warms up. I'm not taking any readings from that gauge. I do have the innovate wideband gauge wired in as well and those are the readings I am giving to you. The autometer gauge effects the circuit when plugged in. I assume it causes a small voltage drop. But the tune was done with this bad signal. What I would like to do is remove the old autometer gauge and only run the innovate but when the autometer gauge is removed my air fuel drops from 14.7 range and sweeps around 13.0. To correct this in ecmlink is it a matter of changing a few values or am I basically starting from scratch with the tune?
 
So if you want there is two ways of doing it if I am reading the instructions correctly for the LC2 the brown wire is your narrowband, The yellow wire is the wideband. 1) Hook the brown wire into pin 4 and yellow wire into pin 15 (egr temp sensor). This will give you a narrowband and a wideband signal to the ecu. You will have to go to you settings and change it. 2) Leave the yellow wire hooked up,get rid of the old sensor, and Simulate the narrowband. Then I would just adjust the maf comps until the AFR's are in the correct spot. You will most likely need to retune. Once you can get the idle under control run a log to see where everything is at. I would recommend running option 2. Ive always hooked the LC1 this way on friends cars.
 
You shouldn't have two gauges/sensors hooked up at once. This wideband is very sensitive to voltage issues so remove the old autometer and follow the instructions above^^. I'm in Tomball if you need help. Although, I don't appreciate you trying to copy my red 1bg ;)
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Fix the wiring/gauge issue first. I'm no professional tuner but I don't like what I see in this tune. In #2, the idle switch isn't working. You're not logging MAF.
Airflowperrev should be around .25
ISC position should be around 30
I don't think the BCS setting are right if that was indeed tuned
 
You shouldn't have two gauges/sensors hooked up at once. This wideband is very sensitive to voltage issues so remove the old autometer and follow the instructions above^^. I'm in Tomball if you need help. Although, I don't appreciate you trying to copy my red 1bg ;)
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You might want to close your hood before driving...
 
I'm no expert either, but I found when trying to run my LC1 with narrow band sim, it didn't output correctly until the "Htr" message was displayed. Depending how I tuned the car, it would either run super lean and stall, until the "htr" message disappeared, and fuel trims would start adjusting. Or it would run rich and stay in open loop like you stated above.

I have since ran the stock sensor with a wideband further down the exhaust without issues.
 
Your stalling is likely not because of your wideband, more likely the wideband result is due to whatever is making the car rich and thats whats causing the car to stall, do you have a vented bov? are you running a mass air sensor or speed density?
 
do you have a vented bov? are you running a mass air sensor or speed density?
His profile says he's using ECMlink w/ GM MAF. No pictures included so the GM MAF could be before or after the BOV. Agree more info would be helpful.
 
I prefer to retain the factory narrow band, then just add a bung for the wideband in an appropriate location. I would advise anyone who wants the best to do the same.

Log the WB through a channel that does something less useful.
 
You 2g guys have more options for inputs than us 1g guys so sometimes running a WB and simulating is all we can do. I have every other input on my car used. I do think it is a good idea to run both if possible, so good point. Not everyone has there car clogged with things like fuel pressure, IAT, MAP etc. If he doesn't have the egr valve, and in Texas I would bet he doesn't, he could input the WB thru that input, as it is rarely used by most.
 
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