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b21ft microsquirt no start

makebrickgovroom

New member
Joined
Apr 15, 2020
Location
Colorado
finally got everything wired up and good to go, now I just need to get the thing started. ive got good sensor readings and engine rpm. i've got a powerstage (bosch 124) wired up to the coil and new-ish plugs and wires, though when pulling the coil cable out while cranking i noticed no spark.

my ms settings are pretty consistent with what i've seen others use to start:
- pwm for high-z (0280150785) injectors set at 25.4ms
- ignition set to basic trigger at 60deg, falling edge, and fixed timing set at 13deg
- haven't ****ed with anything dwell

and here's some data i captured during a crank-no-start:
https://www.dropbox.com/s/x60rtj2823rmnfy/nostart.mlg?dl=0

seems like a no fuel/no spark issue. all sensors and necessary equipment is functional and powered. injectors have power. i haven't verified that my injectors are any good, though, so i might try to swap them. my powerstage wiring could be a tad ****ed up too, but there is a 1k resistor between the sig and power wires.

im at a bit of a loss, so if anyone has some insight it would be greatly appreciated. thanks!
 
Nothing really looks super odd in the log. I don't know where in CO you are but the 75kpa MAP reading seems a little low (would expect ~85kpa for Denver altitude). Also your coolant and air temp sensor cals aren't right. There shouldn't be a 20f temperature difference between them when the engine hasn't been running.

You have a clean RPM signal so you're already doing better than 85% of people who have trouble with aftermarket ECU's.

None of this stuff is difficult, you just need to be methodical about tracing where the issues are. Some examples:

  • Squirt some starting fluid or carb cleaner past the throttle body and crank it. If you don't get a sputter it indicates you're not getting spark.
  • Make sure the injectors and coils are getting power during cranking, not just when the ignition switch is in position 2.
  • Pull a spark plug and look at it, it should be wet or smell like fuel if the injectors work
  • disconnect the injectors and pull all the plugs out, crank it over for a while and wait a few minutes for any potential fuel vapor to clear, reconnect the plugs to the ignition leads and lay them on the header or some clean, grounded metal surface. have someone crank the engine and look for spark, you should be able to clearly see the spark events happening in the right order.
  • put 12v across an injector and shoot compressed air through it to make sure it's not clogged
 
- pwm for high-z (0280150785) injectors set at 25.4ms

Do you mean ReqFuel is 25.4ms? If so, that's ~2x too large (double the fuel that's needed). Is the MS setup for 1 or 2 squirts per cycle?

Do you have a timing light? If so, unplug the injectors and see if you see reasonable timing when cranking (13deg). You can also test the ignition from the Testmodes/Output Test Mode menu. Depending on your wiring, you may need to turn on the fuel pump to get power to the ignition coil/module.

Are you using a narrowband O2 sensor? The AFR in the log file didn't look like a wideband signal.
 
^^^ Is that a setting for the original B&G Firmware? I don't remember seeing it in the MSextra menus.

For the OP: If you're using the B&G Firmware, I'd suggest changing to the latest msextra.com firmware. The msextra firmware has more features, more logging, and is more commonly used here. While the basic functions are the same, the configuration fields and screenshots will be somewhat different between B&G versus MSextra.
 
^^^ Is that a setting for the original B&G Firmware? I don't remember seeing it in the MSextra menus.

For the OP: If you're using the B&G Firmware, I'd suggest changing to the latest msextra.com firmware. The msextra firmware has more features, more logging, and is more commonly used here. While the basic functions are the same, the configuration fields and screenshots will be somewhat different between B&G versus MSextra.

yes, everything's been configured with the b&g firmware. i'll flash the msextra later today and see what i can do. i'm using an aem wideband controller and bosch lsu which i doubt properly configured. i'll fiddle with stuff to see where i can get.

my wiring is pretty standard, at least from what i can tell. main relay powering fuse block which then provides fused power to the fp relay, ms, wideband, ignition, and injectors. ill multimeter everything and double check my crank timing when i'm home.

i'll also probably upload another log once i flash the msextra firmware, depending on if i can't get it started
 
Nothing really looks super odd in the log. I don't know where in CO you are but the 75kpa MAP reading seems a little low (would expect ~85kpa for Denver altitude). Also your coolant and air temp sensor cals aren't right. There shouldn't be a 20f temperature difference between them when the engine hasn't been running.

You have a clean RPM signal so you're already doing better than 85% of people who have trouble with aftermarket ECU's.

None of this stuff is difficult, you just need to be methodical about tracing where the issues are. Some examples:

  • Squirt some starting fluid or carb cleaner past the throttle body and crank it. If you don't get a sputter it indicates you're not getting spark.
  • Make sure the injectors and coils are getting power during cranking, not just when the ignition switch is in position 2.
  • Pull a spark plug and look at it, it should be wet or smell like fuel if the injectors work
  • disconnect the injectors and pull all the plugs out, crank it over for a while and wait a few minutes for any potential fuel vapor to clear, reconnect the plugs to the ignition leads and lay them on the header or some clean, grounded metal surface. have someone crank the engine and look for spark, you should be able to clearly see the spark events happening in the right order.
  • put 12v across an injector and shoot compressed air through it to make sure it's not clogged


thanks for the words of encouragement, i tried really hard to get my hall wiring right the first time. i'll reconfigure my coolant sensor (an lh2.4 one) and see where that gets me. the plugs were dry when i pulled them yesterday morning after trying to start her, so i think my fuel delivery might be a little ****ed. ill double check my wiring and injectors when i get the chance.
 
Once you install the MSextra firmware, try the different CANbus/Testmodes>>>OutputTestMode checks to verify that fuel pumps / ignition / injectors / IAC are somewhat working. Depending on your relay setup, you may need to turn on the fuel pumps to power the injectors/ignition.

If this all looks good, I'd try a timing light during cranking (injectors unplugged if you want to avoid extra washdown).
 
Once you install the MSextra firmware, try the different CANbus/Testmodes>>>OutputTestMode checks to verify that fuel pumps / ignition / injectors / IAC are somewhat working. Depending on your relay setup, you may need to turn on the fuel pumps to power the injectors/ignition.

If this all looks good, I'd try a timing light during cranking (injectors unplugged if you want to avoid extra washdown).



this is genius and a really ****in useful feature. thanks for pointing it out, ive determined that my fuel pumps and injectors work (now), but I don't think im getting any power to my coil. i've wired my 124 amplifier as:
1 - ground
2- coil neg
3- shield
4- 12v
5- sig

i just removed the 1k resistor between the 12v and the sig, which may prove to be a mistake. ill fiddle with the wiring here in a little. here's another log with the new firmware and some tweaked stuff:

https://www.dropbox.com/s/t8qt706ne8s6r45/nostart3.mlg?dl=0

lemme know what you think of that -- and does 82kpa seem ok for boulder, co?
 
I think you've got pins 1 and 2 swapped - see http://www.msextra.com/doc/pdf/html/Microsquirt_Hardware-3.4.pdf/Microsquirt_Hardware-3.4-66.html
Or download the whole manual from: https://www.msextra.com/manuals/ms2manuals/

You shouldn't need a 1K pullup on the ignition module, but probably do need it on the distributor sensor wire to MS. LH2.2 disti, right?

And yes, Boulder's ~82kPa (your last log was ~75kPa/8000' - did you move the car, or did an electrical offset change?)


that makes sense, i can't believe i missed that. i just swapped the wires around, but still nothing. i do have the hall resistor wired up proper, and i have no idea where i gathered that something similar would work for the ignition module. i got a timing light today (man they're expensive) and i've verified spark, so i'm thinking my timing isn't great. the car hasn't budged (but it needs to soon, since i'm moving out of gunbarrel down to 30th, which has been a major pita with covid ) but i did change some settings with the map and clt sensors. thanks for your help so far, it's extremely appreciated.
 
Have you seen the MegaSquirt-2 Setting Up manual? http://www.msextra.com/doc/pdf/Megasquirt2_Setting_Up-3.4.pdf (I don't think there is MicroSquirt-specific version, but the MegaSquirt-2 instructions should be very close.)

Where are you in these setting up steps? I forget what values to use for the IAT sensor and CLT sensor calibrations. Ask here if you don't have these already. If you have a wideband O2 sensor, it should be included in the drop-down calibration menu.

I never thought about the cost of a timing light -- they used to be very common, and pretty cheap from Sears/Wards/Kmart, but that was 30 years ago before electronic fuel injection. If you have some white paint, it helps to paint around the timing mark on the pulley (leave a black space at the groove) and the marks on the timing cover.

What's your get-it-running date? I'm working 40+ hours a week these days but might be able to meet you (with appropriate covid attire) some evening/weekend.
 
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