no rpm while cranking

[akeboshi]

hello,
i recently completed ms2 and testing with the stim checked out good. all sensors read good. i installed it in the car and started to crank...no rpm signal. i tried to play with the trim pot r57 i think it is (have vr wired) and i got a signal for a split second (it actually fired a couple of cylinders) im running embedded code 2.890 and i set up ms2 for direct coil control, jumpered igbtin to js10 and igbtout to ign like it say to as well as setting parameters as follows- Coil Charging Scheme to 'standard coil charge',
Spark Output to 'going high (inverted)

do i need to mess with the trim pot more (battery died charging now) or do something else?
im using a 77 280z distributor with vr sensor and it has 2 wires a red and a green. got the green wired to coax wire stuff and red to coax white. and blaster 2 coil with + to fuel relay and - to pin 36

[akeboshi]

got rpm signal now (after adjusting trim pot more) but now it wont fire. i have spark and fuel but it still wont fire. i dont know what is wrong. i truned it over and over for a while then took the plugs out and they were wet with fuel but i turned it over again after installing the plugs then pulling the plugs again but no fuel. i give up for the day.

[Matt Cramer]

Check the timing with a timing light and make sure it's something reasonable, then you'll want to adjust the fuel to get it to start.

[akeboshi]

just great!!!!!! i went out to try and check the timing like you said and went to connect ms2 to the laptop and it wont connect. last night before quitting i accidentally plugged the db37 to the ms2 while the ignition was hot and i saw some sparks by the fuses. i popped both of the injector fuses and now ms2 wont work on the stim board or connect to laptop. the fuel pump light will come on for a second or two and go back out. most of the time the fuel pump led on the stim does this but a couple of times the ignition light did it also. the first time i connected the stim to the ms2 it worked for like 2 seconds then did the symptoms i just wrote. i tried shorting the bootloader pin and like the troubleshooting say the leds on the ms2 briefly flash. im about to just cut my losses and sell the whole car. i have had nothing but trouble and i think im over my head with this. if you have any suggestions on what it could be that would be nice. i tried to do the hyperterminal test but the free trial has expired. and i checked c22 and d19 and the yboth physically look good. this is making me frustrated because it was working perfectly before this happened. please help!!!!!!!!!!!!!

[Matt Cramer]

Let me know what main board you have, and I'll go over how to check it for damage.

[akeboshi]

its the ms2 v 3.0 pcb. i dont pysically see anything wrong with it and i dont understand how it could be damaged as i have fuses everywhere the is supposed to be one. thanks always for the help matt.

[Matt Cramer]

To check for a short in the Megasquirt PCB, power up the Megasquirt on a Stimulator or on the car and check the following points for voltage with a multimeter.

You should find the same voltage as the battery voltage on the following points: S12, S12C, the center legs of Q9 and Q12, the left (non-banded) end of D3, the left leg of U5, and the left (banded) end of D9.

You should have 5 volts at the following points: S5, the two +5V holes in the proto area, the right (non-banded) end of D9, the right leg of U5, the left (banded) end of D19, and pins 1, 20, and 31 of the CPU.

Let me know where you find the correct voltages, and where you find the wrong ones.

[akeboshi]

i couldnt find s12 but s12c is 11.8 center leg of q9 and q12 are 12.59, left (nonbanded) end of d3 is 12.54 left leg of u5 is 11.72 and left (banded) end of d9 is 11.72.

i also couldnt find s5 but the proto holes are both 4.93, right non banded end of d9 is 5.0, right leg of u5 is 5.0, left (banded end) of d19 is 5.2 and pins 1,20, and 31 are all 5.02 volts.

after i did all of these readings and put the controller back on the stim everything started working good. i dont know why. i also did all of the voltage tests with the injector fuses missing as they blew out again. i replaced them after testing and gave it another try to start her up and she poped a few times and those few times the timing light was lighting up on 15 deg but after a few turns it stopped blinking. it seems as though im getting inconsistent spark but i am getting a reliable tach at about 100 to 150 rpms on cranking. im getting fuel and spark but she wont start....

[akeboshi]

i had something else to add, im only getting like around 100 rpms on cranking up to 150 but not more. when it starts to slow down im only getting like 16 rpms and no spark and im assuming im not getting spark because of low rpm signal. i should also add that i have every single ground wire soldered to one terminal lug and bolted to the negative on the battery.

[trakkies]

[snip]
i should also add that i have every single ground wire soldered to one terminal lug and bolted to the negative on the battery.

Does that include the sensor grounds?

[Matt Cramer]

About blowing the injector fuses - are you running low or high impedance injectors?

[akeboshi]

I'm running low impedance injectors with the Pam circuit and I have even included the sensors on the single lug to battery ground

[akeboshi]

Pwm* iPhone autocorrect

[trakkies]

I'm running low impedance injectors with the Pam circuit and I have even included the sensors on the single lug to battery ground

IMHO, not a good idea. The should all go to a single pin in the DB37 connector - as per the wiring diagram. The MS grounds as you've done.

[Matt Cramer]

Pwm* iPhone autocorrect

If PWM is configured wrong, you can end up drawing several amps per injector. Could you post a copy of your MSQ?

[akeboshi]

ill post one as soon as i get off work. i think i found the problem to my spark issue though, i had the oil pump /distributor driveshaft in backwards so i was 180degrees off in timing. i tried to start it after i fixed this but my battery died and the starter needed to cool off but it sputtered like it was gonna start!! . i put the battery on a good charger overnight so it should be good to go when i get off work.

[akeboshi]

to trakkies,

IMHO, not a good idea. The should all go to a single pin in the DB37 connector - as per the wiring diagram. The MS grounds as you've done.


im sorry but i dont quite undertand what you mean by this, do you mean ground all the sensors somewhere other than together with the megasquirt grounds and ground all 7 of the megasquirt grounds directly on the battery? im sorry could you clarify or let me know how you set up your grounds please. thanks for the help btw, this forum has great support!

[akeboshi]

heres an msq of the last time i tried to start it up. it wont even sputter at all and all three lights on the controller blink at once in about 1 second intervals. i can hear all of the injectors chattering and i can smell fuel out the exhaust so i know i am getting fuel. spark just doesnt want to play though. im not getting spark from the coil though. i checked for 12v to the coil and i only get around 6 volts when cranking. is that normal?

[akeboshi]

great, now im back where i started with no tach signal..... this is getting very annoying and i can check the vr signal because i dont have an oscilloscope. i turned both vr pots fully counterclockwise and still nothing. i just dont know.... it looks like from all the msqs i made that i was never getting a signal but i saw the tach on tunerstudio go to like 150 rpm and i can hear the fuel pump kick on. now though i dont get a signal in tunerstudio for tach but i can still hear the fuel pump kick on. im getting sick of messing with this stuff. it should have aleady been running.

[akeboshi]

ok so call me crazy but it looks like i only get tach signal when i put the tps to the floor. this is after i readjusted the air gap on the dizzy and reflashed the ecu with 2.89000 code and reset up the controller with all the base settings like injector stuff and displacement and whatnot.i didnt touch the ve table and the first time i cranked it over, it fired a few cylinders then nothing. all three leds on the controller blink together for like one or two second on and off and it sounds like the relays are clicking on and off as well. what am i doing wrong for this to not work. i have the jumpers for the vr sensor jumpered, i have d1and d2 jumpered, c12 and c30 are not installed or jumpered and i have igbtin jumpered to js10 for direct coil control firing a blaster 2 coil. pin 36 on negative coil and 12v wired to fuel pump relay, the ign wire (shielded grey wire with white core wire) is connected as such, red reluctor wire to white core wire and shielding wired to green reluctor wire with the DIYAutoTune harness which the shielding is hooked up to pin 2 on db37 and the white wire hooked up to pin 24. do i have all of this wired in right? im using a 1977 280z (l28e) vacuum and centrifugal advance dizzy with the mechanical advance welded and vacuum capped with a nipple. i was reading over the megamanual again and i noticed that in step 50 to do either 50a or 50b for hall effect but not both. i had c30 installed but not c12. i cut it out when i noticed it a week ago. like i said though i have jumpers installed for vr sensor. as far as i can tell the controller is fine because it works flawlessly with the stim. i also wondered if the fuel pump relay is supposed to kick off when its not getting told to run ( no signal voltage to the relay, thats how it works right?) i also check the dizzy to see if i get a/c voltage when i spin the dizzy in my hand and it does. here is the msq of the engine turnover. look carefully at the tps and tach as they coordinate together with no tach when the throttle isnt pressed and tach signal when throttle is all the way pressed down.