Help with how mt05 ecu works

Bradsonfire · 07-12-2023, 09:27 AM

Im trying to fix a friends bike (chinese moped). Issue is the injectors. When you try to start the bike the injector only fires once. The ecu isnt generating the ground pulses to fire the injector (tested with bulb)
As i understand injector has a permanent live and gets a pulsed
Ecu is a delphi mt05
ground from pin 5 on the ecu.
What feeds into the ecu that it uses to generate the ground pulses. Is it from generator pickups or tps or .... And if you know what pin the input is on would be really helpful. Just want to workout what feed the ecu is not getting

Have tried a spare ecu (cant guarantee it works but unlikely both have the same issue)

Bradsonfire · 07-12-2023, 10:20 AM

Weird update. The original issue is it suddenly lost spark and injection neither worked. Guy shorted the sidestand switch and that brought the spark back. I just removed the short and now it runs fine....why would the sidestand circuit be related to whether the ecu fires the injector? Very confused here haha

**JerryHawk250** · 07-12-2023, 10:48 AM

Glad you figured it out.

Thumper · 07-12-2023, 11:40 AM

Quote:

Originally Posted by Bradsonfire

Weird update. The original issue is it suddenly lost spark and injection neither worked. Guy shorted the sidestand switch and that brought the spark back. I just removed the short and now it runs fine....why would the sidestand circuit be related to whether the ecu fires the injector? Very confused here haha

Side stand kill switch is a safety "feature". It sounds like it failed in the "defeat" position!

Nice fix!

zero_dgz · 07-13-2023, 02:38 PM

Having a safety switch on the kickstand is not unusual (well, it is for Chinese bikes but not for brand name bikes in general) and the intent is to prevent the user from riding off with the kick stand deployed, ready to unexpectedly dig into the pavement and send you ass over heels. Typically these are part of the kill switch circuit, and will cut the engine either via grounding out the CDI or preventing fuel injection, or both, if the bike is put into gear with the kickstand down.

07-12-2023, 09:27 AM	#1
Bradsonfire Join Date: Jul 2023 Posts: 2	Help with how mt05 ecu works Im trying to fix a friends bike (chinese moped). Issue is the injectors. When you try to start the bike the injector only fires once. The ecu isnt generating the ground pulses to fire the injector (tested with bulb) As i understand injector has a permanent live and gets a pulsed Ecu is a delphi mt05 ground from pin 5 on the ecu. What feeds into the ecu that it uses to generate the ground pulses. Is it from generator pickups or tps or .... And if you know what pin the input is on would be really helpful. Just want to workout what feed the ecu is not getting Have tried a spare ecu (cant guarantee it works but unlikely both have the same issue)
	0

07-12-2023, 10:48 AM	#3
JerryHawk250 Moderator Join Date: Oct 2016 Location: Houma, La. Posts: 11,574	Glad you figured it out. __________________ 2023 Lifan Lycan 250 Chopper 2023 Venom Evader 2022 Lifan KPX250 2020 Kawasaki Vulcan S 2004 Honda ST 1300 2016 Black Hawk 250 (sold) Keihin PE30 carb,125 main,38 slow.Pod filter,ported & decked head 10:1 CR,Direct Ignition Coil,15/40Sprockets,NGK DPR8EIX-9,De-Cat,Dual Oil Cooler,Digital Cluster 2016 Cazador180 XL 2014 Coolster150 JerryHawk250.com My YouTube Channel
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07-12-2023, 10:20 AM	#2
Bradsonfire Join Date: Jul 2023 Posts: 2	Weird update. The original issue is it suddenly lost spark and injection neither worked. Guy shorted the sidestand switch and that brought the spark back. I just removed the short and now it runs fine....why would the sidestand circuit be related to whether the ecu fires the injector? Very confused here haha
	2

07-13-2023, 02:38 PM	#5
zero_dgz Join Date: Jan 2020 Posts: 254	Having a safety switch on the kickstand is not unusual (well, it is for Chinese bikes but not for brand name bikes in general) and the intent is to prevent the user from riding off with the kick stand deployed, ready to unexpectedly dig into the pavement and send you ass over heels. Typically these are part of the kill switch circuit, and will cut the engine either via grounding out the CDI or preventing fuel injection, or both, if the bike is put into gear with the kickstand down.
	0