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Rev built MS3 basic afr problems

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Old 07-01-2014, 02:27 PM
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Default Rev built MS3 basic afr problems

Just got a rev ms3 basic and having problems getting an afr reading in TS. While idling, it stays at 7.3 and doesn't change. My WB gauge fluctuates slightly. (PLX devices WB) When I shut it off, it goes to 10 (offline). I have the WB wired through the db37 using the power/ground and the yellow wire for analog output.

Also have the immobilizer light flashing while running.
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Old 07-01-2014, 10:06 PM
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I verified I am using the wideband output from the WB. It was ~3.5 volts and 16.2 afr (not running). Car starts and drives ok but I can't run VEAL until I get this sorted out.
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Old 07-02-2014, 01:28 AM
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Have you calibrated the WB in TS? Not running the WB should show a value at the upper (lean) end 19-21 (depending on you WB).
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Old 07-02-2014, 02:21 AM
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Which PLX wideband? Which wire from the wideband to which wire on the MS3? The MS3's serial number?
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Old 07-02-2014, 03:36 AM
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Just realized which Steve you are.

Go to Fuel Settings -> AFR/EGO Control, and set "EGO1 Port" to "Normal EGO".
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Old 07-02-2014, 07:20 AM
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Zaphod.....I thought I found the problem when I looked at the calibration table and saw that it was blank. Didn't know at the time that TS doesn't remember the setting.

Rev....I'll check that later today. Your MS3 is awesome by the way. Started on first try and I have never seen afr's hold that steady at idle.
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Old 07-02-2014, 04:15 PM
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Originally Posted by Reverant
Just realized which Steve you are.

Go to Fuel Settings -> AFR/EGO Control, and set "EGO1 Port" to "Normal EGO".
With the EGO1 port set to CAN EGO (originally set to), the afr is 7.3 and idle oscillates a little before settling down. Changing it to normal EGO changes the afr to 10 and idle goes to **** quick with no change to afr display other than 10. Would it be better if I manually put in the calibration from the plx manual since it is "the first one ever built?"
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Old 07-02-2014, 04:29 PM
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Changed calibration to custom linear and put the supplied numbers and it idles between 2-3k with no change in display. Anything else to check?

The numbers matched the default plx numbers from the drop down.....0v = 10afr and 5v = 20afr

Last edited by stratosteve; 07-02-2014 at 04:33 PM. Reason: coo coo for cocoa puffs
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Old 07-02-2014, 05:07 PM
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You need to restart the ECU (ie ignition off and on again) after setting the port to Normal EGO.
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Old 07-02-2014, 07:37 PM
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You mean I have to read and follow the large banner that goes across the screen when changing certain parameters? Sheesh

Normal for WB gauge to read different than TS? I read about voltage differences being caused by different grounds but using the supplied ground on the db37 would prevent that?
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Old 07-02-2014, 10:45 PM
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Originally Posted by stratosteve
You mean I have to read and follow the large banner that goes across the screen when changing certain parameters? Sheesh

Normal for WB gauge to read different than TS? I read about voltage differences being caused by different grounds but using the supplied ground on the db37 would prevent that?
Nope, I am using the supplied db37 ground and have about 1V offset. I got this nifty little box in the mail yesterday that I need to figure out how to install Reverent makes them for any wide band that has an optional digital output as well as the analog output... then it matches exactly.

Does your wide band have a programing cable, logging cable, or something similar that has a digital out?

Keith
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Old 07-03-2014, 01:46 AM
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The PLX does have a digital output but I haven't figured out the protocol yet. I've bought an SM-AFR Gen3 just for that but I have other side projects to deal with.

Steve, does the gauge in TS follow the PLX gauge at all? Ie even if they have a large offset?
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Old 07-03-2014, 07:50 AM
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My plx is analog only.

Rev, TS appears to follow the plx gauge but I haven't nailed down the exact voltage difference. Seems to be ~.6v. We had a power outage last night and I didn't get much play time.
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Old 07-03-2014, 09:31 AM
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Correction on previous post. It is .6 afr not volts.

Is the normal procedure to alter the afr table by the offset to achieve the correct afr? I am currently running .6 afr higher just about everywhere. So 14.1 to 14.2 at cruise on my WB gauge and 14.7 on TS.
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Old 07-03-2014, 01:00 PM
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Did a custom linear calibration for WB and changed the 5v = 20 to 5v = 19.25. It is much better now. Is that change excessive?
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Old 07-03-2014, 01:07 PM
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Originally Posted by stratosteve
Did a custom linear calibration for WB and changed the 5v = 20 to 5v = 19.25. It is much better now. Is that change excessive?
If you want it to remain correctly linear you need to lower the upper and lower points by the same amount. Then the easiest way to check is to run the engine for a while, then shut it off and go back to accessory on with the key. Without the engine running it will read a very steady A/F ratio and you can compare the gauge with the TS A/F reading much easier than with the engine running.

Keith
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Old 07-03-2014, 02:03 PM
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Thanks

So it is a 2 to 1 slope. If my math is correct, .3v should equal .6 afr? I should take .3v off the bottom and top and see where I am.
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Old 07-04-2014, 12:34 PM
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I think I have the afr under control now. Still need to work on the afr table a bit. I think it's a bit too rich under part throttle.

They only issues I have remaining are high idle on start up and it won't start unless I have the throttle opened a bit.

Car runs better than it ever has. Pulls hard and smooth. I just need to get the couple things done above. I should have done this sooner.
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Old 07-05-2014, 08:37 PM
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Originally Posted by Twodoor
If you want it to remain correctly linear you need to lower the upper and lower points by the same amount. Then the easiest way to check is to run the engine for a while, then shut it off and go back to accessory on with the key. Without the engine running it will read a very steady A/F ratio and you can compare the gauge with the TS A/F reading much easier than with the engine running.

Keith
My method for doing this was:

Make all of your idle cells have the same ignition advance (you should probably already have this)
Richen VE in idle cells until you're running at about 11.0 AFR
Tune the custom calibration table until TS and the gauge agree in rich areas. Write this down.
Lean out VE in idle cells until you're running about 16.0 AFR (you'll have a hard time idling any leaner)
Tune the custom calibration table until TS and gauge agree in lean areas. Write this down.

Put both back into custom calibration, and you should be good to go.
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Old 07-07-2014, 04:04 PM
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Idle and start issues resolved. Reduced the idle pwm into the 30's (in case a search results in this thread)

Next step, I am going to continue with veal at a less aggressive cell change to fine tune. Then moving on to the spark table.
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