Injectors firing without the engine running

For discussing MicroSquirt (TM) configuration and tuning of fuel parameters (including idle valves, etc.).
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arr_kid
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Post by arr_kid »

Megatune engine status still reports the engine in running mode as soon as it powers up, shows cranking while turning over (no plugs or injectors connected) then the running mode goes out after cranking (Engine status = zero). Could someone confirm this is correct please?
Ok, found a start up log http://www.microsquirt.com/viewtopic.php?t=22675 which suggests this is normal.

Just need some advice on settings to get the HiZ injectors to fire.
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grippo
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Post by grippo »

Does the MT rpm guage show a reasonable rpm while you are cranking ?

Does it ever drop momentarily to zero ?

If you put a test light or led tester in place of an injector does it flash the least bit ?
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MegaScott
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Post by MegaScott »

MicroSquirt does not have PWM injector drive capability, so if you are driving more than 2 Low Z injectors you will probably need to add current limit resistors.
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arr_kid
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Post by arr_kid »

Cranking looks good as per attached, if a little sluggish.

I ran the Injector Test Mode (20msec PW, 60msec offtime) and could hear the injectors making the faintest of clicks. Test meter showed almost 1 volt across the HiZ injector. When I replaced it with a small 12v test bulb it glowed very very dim.
I noticed when I switched back to Normal Mode the injectors carried on as if they were in Test Mode and I couldn’t stop them until I re-flashed.

I switched back to the low impedance injectors and resistors and went for start up but no signs of life.

It’s as if the drivers aren’t passing any decent amount of current. The mosfets I replaced were http://uk.farnell.com/jsp/Semiconductor ... stid=15468

Next step is to short pins 3 & 4 on U6/7 with the ammeter and see what the injectors are pulling and I have a good ground path through the board. Also while I’m in there I’ll try & see what the processor is outputting. What kind of voltage would I expect to see out of the processor on pins 2 & 4?
Attachments
cranking.xls
(56.42 KiB) Downloaded 53 times
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arr_kid
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Post by arr_kid »

Stumped. When I short Pins 3 & 4 on U6 & U7 with the ammeter I get a nice click from the injectors and pull a healthy 2.69amps & 2.72 amps respectively. I used the scope between U6 Pin 1 and ground but didn’t make much sense of it. In Injector Test Mode there seems to be about 1volt oscillating. grrrrr
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arr_kid
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Post by arr_kid »

S'pose I could always re-brand it as a Micro-Jolt :idea:
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arr_kid
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Post by arr_kid »

Unresolved
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