Wrong AFR readings in MT

AbeFM · Post by **AbeFM** » Sat Feb 16, 2008 12:34 am

Is there some way to force a reading from the megasquirt of the AFR, even with the motor not running? It would be *trivial* then to test this.

hassmaschine · Post by **hassmaschine** » Sat Feb 16, 2008 10:32 am

I don't think so, the O2 sensor needs to be hot to work, and if you try to use it with the engine off I don't think it will read correctly anyway.

6040solder · Post by **6040solder** » Sat Feb 16, 2008 11:18 am

Actually, a wideband doesn't "need to be hot" it "needs to be a particular temperature" hence it has a heater circuit in it which regulates the temerature as accurately as the controller you have hooked to it is capable of. so yes, in the same way that it works correctly when you do a free air calibration it will work any other time provided it is powered up.

AbeFM · Post by **AbeFM** » Sat Feb 16, 2008 6:55 pm

With the Innovative, you can tell it to go to a predetermined voltage during warmup, making it easy to check your "guage". I tuned my analog this way, but would like to be able to the MS that way. The colder it is, the better.

ronchinoy · Post by **ronchinoy** » Thu Feb 21, 2008 6:12 am

can anybody outline the fix from Jaw and MS
Jaw setting is AFR 10.18 - Lamda .69 Vout1=1.02 to AFR 34.28 Lamda 2.33 Vout 3.43
Should one just chose custom WB and enter the value in Mega tune.
Or should one reprogram the JAW values to match say the Tech Edge or LM1. ANd then chose that option.
Whats the most popular route taken here.
Can JAW be added to the options in megatune. It seems to be catching on real fast.

PhoB · Post by **PhoB** » Mon Mar 10, 2008 4:31 pm

Iam using TechEdge 2A0 with display and WBlin signal for MS(in MT i setup for TechEdge WB). Display shows aproximately about 0.4 AFR less(richer mixture) than in MT ! Why? Which one is correct?

Beta19 code

cguenther · Post by **cguenther** » Tue Mar 11, 2008 3:26 am

Hi,

just another point of view: does anyone has checked his LC-1/JAW/Techedge/whatever against a calibrated emission-tester?

ive done this with the following setup: LC-1 in the exhaust just after the engine, probe of emission-tester in the exhaust.

i found the LC-1 to be different from the calibrated tester by approx. 0.4 lambda/0.9 AFR. after a free air calibration the lc-1 is still off...

the output-curve on the lc-1 is linear, but i dont have the starting/end-values in mind. what do you have as values for 0V/5V or 1V/4V put into the LC-1 software?

im using MT ...p1, which should be correct in interpreting the voltage from the LC-1, correct? or is it recommended to choose default WB and put in the same values as in the LC-1 software?

best regards,
carsten

6040solder · Post by **6040solder** » Tue Mar 11, 2008 4:00 am

cguenther wrote:ive done this with the following setup: LC-1 in the exhaust just after the engine, probe of emission-tester in the exhaust.

i found the LC-1 to be different from the calibrated tester by approx. 0.4 lambda/0.9 AFR. after a free air calibration the lc-1 is still off...

Were you using ms/mt to read it? or the Innovate software?

cguenther · Post by **cguenther** » Tue Mar 11, 2008 4:45 am

i used both, the lc-1 soft and the mt-soft. did not check that both softwares shows the same output which would answer my question

still noticed that the lc-1 output was so far offset from a validated emission tester. doing the tuning with the lc-1 only would hav led to a very lean mixture. so my idea is to calibrate the lc-1#s output to the values measured by the official tester.

did anyone did this before?

best regards
carsten

6040solder · Post by **6040solder** » Tue Mar 11, 2008 4:50 am

Calibrated official stuff has been known to be wrong before, I'd X reference it around before assuming too much. Also, it might pay to sample further down the stream where more later combustion has occurred. That could explain your difference too.

cguenther · Post by **cguenther** » Tue Mar 11, 2008 4:53 am

ok, thanks for your reply. additionally, it might be that external gases are entering the exhaust-path.

btw: the AFR-output in MT is "flickering" a bit, is there any kind of "filter" to smoothen the value shown?

best regards
carsten

hassmaschine · Post by **hassmaschine** » Tue Mar 11, 2008 8:21 am

comparing the LC-1 directly after the engine and a seperate sensor at the tailpipe will get two different readings anyway - esp. if your car has a catalytic convertor.

cguenther · Post by **cguenther** » Tue Mar 11, 2008 8:30 am

shure, but there is no "such thing"

turboy · Post by **turboy** » Tue Mar 11, 2008 10:36 am

I had the same problem. The display is using the serial data of the 2A0 controller to display afr while the analog wblin voltage is used via a/d converter and lookup table to display afr. This table is a bit course I think. You can correct the wb voltage output to match the te display, look here for the procedure: http://www.wbo2.com/faqs/svoutoffset.htm

Simon

Sent: Tuesday, March 11, 2008 12:31 AM
Subject: Wrong AFR readings in MT

Iam using TechEdge 2A0 with display and WBlin signal for MS(in MT i setup for TechEdge WB). Display shows aproximately about 0.4 AFR less(richer mixture) than in MT ! Why? Which one is correct?

Beta19 code

PuntoGT 1.6T + MS2extra

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PhoB · Post by **PhoB** » Tue Mar 11, 2008 1:04 pm

turboy wrote:I had the same problem. The display is using the serial data of the 2A0 controller to display afr while the analog wblin voltage is used via a/d converter and lookup table to display afr. This table is a bit course I think. You can correct the wb voltage output to match the te display, look here for the procedure: http://www.wbo2.com/faqs/svoutoffset.htm

Simon

Wow, thanks a lot! Im going to fix it tomorrow!

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Wrong AFR readings in MT

Wrong AFR readings in MT

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