MS-II Megasquirt Issues

[NicT]

So ive seen a bit of chit chat on these forums about Megasquirts so i thought id throw my problem out there.

I have a MS-II V3 board, loaded with MSExtra 2.1.0d. Got a homebrew stimulator i built got it all going and my air temp, water temp are sitting on 170degrees, MAP sensor is maxed out at 250kpa, and tps is on 100% regardless of what i do with my Potentiametres.

There is documentation stating that the above errors relate to a short either on the stimulator or the board itself. However tracing everything i couldnt find any shorts on the board or my stim. All sensor pots have a common ground with the ecu and pin 19 (like states on MS docs) and when i adjust all my sensors i get a voltage change across the pins.

I even traced back to the CPU itself and across the inputs on the CPU i can change the voltage on my temp sensors on tps (from 0 - 5volts depending on position of POT) and i can change my MAP sensor voltage from 1.1volts to 3.3volts with a siringe and a rubber hose. This to me would seem that the boards dont have any shorts but something is going on elsewhere.

Has anyone else had issues like this when first setting up there MS?

[slacker.cam]

I have a few ideas about what may be causing your issues but some others on here may be more knowledgeable than I am as I haven't done any MS stuff for a couple of years. Where are you located? I have a normal stimulator and a JimStim that you can borrow if you're in Auckland and want to eliminate the variable of your DIY stim.

Are you sure that you're getting good comms? Is the timer counting up in TunerStudio and is it showing connected/disconnected when you power cycle the MS?

[barf]

and if you're in christchurch you're welcome to borrow one of my stimulators.

all sensors require calibration, check in TunerStudio Tools -> Sensor Calibration for MAP sensor calibration. for TPS there is a wizard, for thermistors (temperature) they are usually set by three known points of resistance-versus-temperature ("Calibrate Thermistor Tables" in TunerStudio) or; if you know the coefficient of the thermistor there is a more precise method.

another check, is to see if a refererence voltage is output from the sensor pins on the DB37, you should see 5.0v on the IAT and CLT input pins, on an unloaded circuit.

[NicT]

I live out in the dirty south of auckland, i might take you up on your offer tho and come grab in a couple of weekends time (have a wedding to attend this one).

Ill look into running the calibration wizards tonight. Its a pain but im using an old PC with a serial input to do all my shit on, and it has no internet connection so i have to unplug my computer to do any MS shit, then plug it back in to surf the net and research some junk.

[NicT]

I have fixed this problem, it was a broken join on the CPU itself for the referance voltage pin.

Took hours of searching and probeing to find it. Have no fixed this problem and all A to Ds run perfect