MSefi.com read only forum (Jan.15,2018)

MS2 v3 ini 2.905 I have a hall sensor with a 4.05v input signal at the OPTIN jumper and also at pin 14 of JP2. At pin 17 [JP2] and JS10jmp there is no signal when powering-up or cranking . The BIP 373[Q16] has no input signal ,ground is good , the center pin has a constant output of 11.98 volts when power is on or cranking. The center pin output does not change. The engine started-ran before , the only change made has been upgrading to 2.905 code and adding the IAC jumpers . Before I was using a bosch thermal idle valve not megasquirt . I used an LED test light and multimeter to test components in the ignition circuit and everything seems within spec on the input side up to the MS-II daughterboard. Which is bad ? Daughterboard or Q16 ?

Do you see a tach signal with TunerStudio? Have you got a stim? With that, the injector LEDs will show a tach signal - the ign LED a signal to the coil. In other words, you need to ascertain if the tach signal (from the hall effect sensor) to the MS is present before checking the output stage (BIP 373)

MS 2 v3 ini 2.905 Worked fine on the stim, has an input of up to 4.05 volts from the hall sensor. I checked the output circuit from the DB37 to the MSD-6 box and have voltage 11-11.98 volts backfeeding to DB-37 pin 36. Resistance from carbody grd to pin 36 is 139.4 ohms. Resistance from MSD-6 case to pin 36 is 139.4 ohm. Apparently something is shorted in the MSD-6 box. Hopefully this backfeed voltage hasn't damaged anything in the Megasquirt box. Thankyou , John.

MS2 v3 2.905 I switched to direct coil control and still have no spark . LED tester blinks while cranking, stays solid with key on when testing at OPTIN jmp but no longer lights at U1 pin 14 , ground is proto area Gnd . Fuel pump ran while cranking after switching to direct coil control and test LED lit solid at DB-37 pins 33 , 35 [inj1 inj2 ] but did not flash at these pins. R13 checked at 4.13k ohms , R12 at 389 , C11 has 1.05v on one side 0v on other. R13 has 4.95v on side towards DB-9 , 1.05v on other lead. R 12 has 4.01v on side towards DB-37 and 1.10v on other. What volts , ohms ,etc,.. should I have for U3 , Q16 etc,... . During setup while on the stim it worked fine. Tuner studio showed a tach signal which changed with the stim adjustment. The only issue was the ms2 didn't respond on the first power-up but does on the second power-up. This unit has always done that regardless of code or ignition system used. When in the car the engine never starts when you turn the power on , it starts when the key is turned-on , then off , then back on. Don't know why but it does. Thankyou , John.

Could you do a log of it cranking? We need to sort out if it's an input or output fault.

I changed to a stock Dodge coil known to work before datalogging , changed msq accordingly. John.

Here is a datalog on the stim. Cranking, run at various rpms. Comparing the rpm to SyncStat you can see were the processor doesn't respond to all inputs from the rpm pot at low [starting] rpms , this is also how it behaves when in the car. Matt Cramer suggested I check the BIP 373 pins [Q 16]. Checked resistance from pins to heatsink while cold then after ran on stim which raised temp of Q16 slightly. Pin nearest DB-37 has .4 ohm hot or cold , center pin has 6.7 ohms cold and no reading when warm, inner pin has no reading when cold and 5.63k ohms warm. The inner pin reading is jumping around when warm. While on the stim I checked voltages of center pin at different rpms using the proto area Gnd. 75rpm-3.35v ,210-3.20v , 1000-3.01v , 2000-2.66v , 3000-2.31v , 4000-1.96v , 5000-1.63v , 6000-1.42v , 7000-1.41 , 8000rpm-1.42v . R43 is installed on this board ,R57 is not installed. I replaced U3 and R13 with no change noticed. Ignition does fire when a test jumper is removed from center pin just like points cars do. Thankyou , John.

Turbo2.2coupe wrote:

2012-07-23_19.42.01.msl

2012-07-23_19.34.34.msq rewrite 2.msq

I changed to a stock Dodge coil known to work before datalogging , changed msq accordingly. John.

You're not getting an RPM signal. Why is the MSQ set up for an 8 tooth wheel with 4 missing teeth?

The ignition is set by what other MS2 users had posted at a forum for the Dodge 2.2/2.5 turbo engines. The engine ran for the past two years on those settings. I had ran the engine with ignition set 4 teeth, 4 missing and had the same performance , so I used what others had posted in their msqs. John.

Turbo2.2coupe wrote:The ignition is set by what other MS2 users had posted at a forum for the Dodge 2.2/2.5 turbo engines. The engine ran for the past two years on those settings. I had ran the engine with ignition set 4 teeth, 4 missing and had the same performance , so I used what others had posted in their msqs. John.

I'm seriously baffled as to why those settings should even work. You're better off turning off the wheel decoding instead.