86 na ms1 v3 board ms,,inovative lm-1(not lc-1) i set the lm-1 for 2.5 volts witch came out to (2.49v) to see if there was a ground offset between the lm1 reading's and the mt reading's and i get a signal going up and down from 2.569 to 2.647 with the engine off and 2.549 to 2.667 with the engine running.I checked the volt coming out of th lm1 with a meter and it is 2.49, so its not the lm-1,i tried ground and power from the ms and from the fuse box and a body ground no differance,the analog ground is the same as the sensors grounds on the ms, i tryed moving that around also it still bounces around, it look's as if the ms is sending voltage to the o2 wire! What would cause this ?

 

Does the LM1 have a reference ground that you can hook to the MS's ground pins?

With the LC1, Techedge 2A0, and 2J1, there is a reference ground that you can hook up to get rid of problems like this.

Also, where do you have the MS itself grounded?

 

the analog ground is going to pin19 Common ground (all sensor’s ground to pin 19) iam thinking this is the reference ground (fyi i tryed unhooking this ground and the volt diffrance increased)

the ms itself is ground to the stock location, (2c pin out of stock harness) i have the stock harness adapted over to the ms!
like this
DB37 PIN”S 86 S4 OEM Harness Plug’s

Pin 19 - Ground -------------------Common ground (all sensor’s ground here)--2C
Pin 26 - TPS Ref voltage 5V ---------------------------------------------------------------2A
Pin 21 - Water temp ------------------------------------------------------------------------2I
Pin 20 - Intake air temp --------------------------------------------------------------------2L
Pin 23 - O2 sensor (shielded oem wire)-------------------------------------------------2D
Pin 30 –Air bypass relay ---------------------------------- --------------------------------1C
Pin 33 - Rear primary injector -------------------------------------------------------------3C
pin 35 - Rear secondary injector---------------- ------------------------------------------3F
Pin 32 - Front primary injector ------------------------------------------------------------3E
Pin 34 - Front secondary injector --------------- -----------------------------------------3H
Pin 28 - Main Relay -------------------------------------------------------------------------3I
Pin 22 - Throttle Sensor --------------------------------------------------------------------2G
Pin 8 - Ground (2R & 3A hook’s together in oem harness)--------------------------2R
Pin 9 - Ground -----------------------------------------------------------------------------3A
Pin 10 - Ground ----------------------------------------------------------------------------3G
Pin 11 - Ground ----------------------------------------------------------------------------3G

i have tryed to wire the lm-1 like this:

power to the lm-1 (ms pin28)
ground both analog and power (ms pin 9) both ground's to pin 19

also like this:

power to lm-1 fuse box (key on pwr)
ground the power connector (were cig lighter adapter was)body
and analog ground to (ms pin 9)

 

Some minor variation is normal, and you will see that scatter more pronounced when using the LC1/LM1 without any smoothing of output. See the Innovate documentation for more details, but you can set update times as instantaneous, 1/3, 1/6, or 1/12 second IIRC. In instantaneous, the output jumps around a fair bit.

Your voltmeter likely does some averaging of measured values, so you may not see the jumpiness. As to why you see that offset, sounds like the infamous grounding issues.

 

ok New news
i tryed hooking a AA batery up to the pin19 ground of the ms and to the siganl wire of the o2 pin23 and the voltage in mt is flat (no bounce),then i tryed a spare car battery (not in my car) for power to the lm-1 and guess what the voltage was once flat again (no bounce) i tested the voltage at the pin 23 o2 (w/volt meter)wire with the lm-1's power hooked to pin28 (power) and pin 19 ground with the analog wire unhooked from the lm-1 and when i turn the lm-1 on i get power coming from the o2 wire,,not alot like .40 or some thing,,then i hook it back up power to fuse box ground to body and i lose the volt's at the o2 wire but mt still bounces around then i riged up to long power wire for the lm-1 i ran them to the battery in the car pos and neg and mt still bounced i tryed differant ground points in the engine bay area mt still bounced,from what i can tell iam getting some kind of fed back from the lm-1's power side(what would normaly go into the cig lighter)!!
any ideas before i send the lm-1 back for testing?

 

oh ya i have had the update times set at 1/6 i dont jump as much there but it still jumps the logs that are posted are at those settings,,i think i should be able to get the offset's adjusted out but the jumps i dont know were to adjust it to!

 

You may want to check in at Innovate's support site. Post your test results there and see if there's a known issue. If you find the solution, be sure to post back here to help others!

 

Here are some pics to give u a better idea of what iam seeing!
this one is with the power to the lm-1 hook to the same power as the ms and the ground hooked to the same grnd as the ms (also the analog ground is hooked here),with it hooked up like this i will see voltage (around .40)at the o2 ms wire w/o the analog wire hooked up! With it hooked up like this it also seams to affect other signal notice the battery voltage and when running all my signals are more jumpy (rpm, map, volts exctra)!



Here the lm-1 is hook up to the fuse box and a body ground the voltage at the o2 wire is gone but i still see a bouncing signal!


Here I used an external car battery to power the lm-1 (not hooked to the car) and the signal doesn’t bounce at all!


and here I hooked a small aa battery in to the o2 wire at the ms and the ms ground wire no bounce at all!

 

Have you tried redoing the free-air calibration of your sensor?

It looks to me like the lm1's analog output might be messed up.

Ken

 

yes just did the free-air cal!!
just got this back from innovative

"Hi,

What you are seeing is ground bounce in the LM-1. This is caused because the LM-1 as portable device has to use a common ground for the WB heater and the rest, incl. analog outs. This is the main reason the LC-1 has separate grounds for each. The only way unfortunately to fix that would be:

a) modify the O2 input of the MS to be differential (best solution)
b) Instead of using the Power connector in the LM-1, solder the ground wire of the LM-1 directly and shorten the power cable as much as possible. This makes the LM-1 no longer portable.

Regards,
Klaus"

Have any ideas on how to do option a?

 

i guess this is what u have to do!now i just have to figure out were to get the stuff to do it with lol!

""how would i do option a? ""

""The attached circuit consists of a Texas Instruments TLV2461 op amp and 4 resistors. When attached to the O2 input of the MS it will convert that input into a true differential one so ground offsets no longer have any effect.

Regards,
Klaus

 

that looks like a simple circuit if you can get a hold of that op amp in small quantities.