Bad injector ground

At idle it is a 12v pulse likely lasting less than 3 milliseconds... So a meter wont show you anything. Now at full throttle under load that pulse is longer to keep the injector open. If the injector were used to near its potential flow volume it might reach like 85% duty cycle or on 85% of the time. But at idle it is maybe has duty cycle of 4 to 5%. Just guessing.

Is there anyway static discharge hammered your ECU?
 
Not that I know of. Only thing that might have done something was when we put the tank back on the seal in the bottom was bad so it leaked gas pretty much on whatever was under it until I got the tank back off. Not sure if that could have done anything
 
Not that I know of. Only thing that might have done something was when we put the tank back on the seal in the bottom was bad so it leaked gas pretty much on whatever was under it until I got the tank back off. Not sure if that could have done anything

Interesting bit to add!

Battery was connected when this happened; yes?

Fuel in a liquid state is not conductive, however once dried, anything dissolved or brought into the mix like oils, dust, dirt, these can be conductive.

Knowing this and if it were mine I would grab a bunch of rags and take every connector apart and spray them with Mass Air Flow sensor cleaner or electrical contact cleaner.

The ecu and everything in that tray must have been soaked. Wear GOGGLES and spray both sides of the connectors soaking everything. Shake out excess and let it dry before assembling.
 
If your multi meter does duty cycle you can check injector pulse reasonably easily. It needs a fairly consistent pulse rate to catch up, its the sort of thing you use on dyno, not really for no-start.

If you have an incandescent bulb type test lamp you can check the injector pulse by unplugging the injector and put the clamp on one wire and the probe on the other wire. Google/youtube "noid light", it works the same way. A noid light will give you some idea if the injector is attempting to pulse at start up. This can lead you in the direction of whether the problem lies in the ECU controlling the earth pulse signal (ouch) or the positive supply to the injector (sometimes supplied by a relay).

I use noid lights when I can't work out why an engine won't start. It can be a quick way of ruling out the ECU, crank angle sensor, immobiliser etc and send you in a different direction.

At a guess I would say your bike has a poor earth supply to the ECU. I would be attempting to supply the ECU with a guaranteed earth, that would entail using a wiring diagram to find all the ECU earth wires and suppling them with earth straight from the battery. It might not be the problem, but it needs to be ruled out.
 
Interesting bit to add!

Battery was connected when this happened; yes?

Fuel in a liquid state is not conductive, however once dried, anything dissolved or brought into the mix like oils, dust, dirt, these can be conductive.

Knowing this and if it were mine I would grab a bunch of rags and take every connector apart and spray them with Mass Air Flow sensor cleaner or electrical contact cleaner.

The ecu and everything in that tray must have been soaked. Wear GOGGLES and spray both sides of the connectors soaking everything. Shake out excess and let it dry before assembling.

Before I came to yall for some help, I had taken pretty much every connector apart and sprayed them with wd40 before putting them back together. Should I take them all apart again and use mass air flow?
 
Well it may seem overkill but yes, I would. Resistance and/or leakage current appears to be an issue.
 
Cleaned the wires with mass air flow cleaner and nothing changed. Any reason I couldnt just run a ground wire to the injector ground and leave it at that? since it runs with them grounded?
 
It is switch that is grounded. For the engine to run it can't be grounded in the conventional straight wire to ground or the injectors ride wide open flooding the engine.

I think you need to swap in different ecu! Fleebay comes to mind...


How much have you ran it with the test lamp in there? Does it rev? Have you road tested it?
 
It is switch that is grounded. For the engine to run it can't be grounded in the conventional straight wire to ground or the injectors ride wide open flooding the engine.

I think you need to swap in different ecu! Fleebay comes to mind...


How much have you ran it with the test lamp in there? Does it rev? Have you road tested it?

Ive probably ran it like 1 minute or so with the test lamp. Yes it revs and everything. Havent driven it like that yet
 
I would not run the engine by just grounding any injector. 1&4 injectors and 2&3 injectors are on the same ecu injector firing together. In other words 1 & 4 cylinder injectors fire at the same time even though only one cylinder is firing off it's compression stroke. You have a problem with the ECU or the wiring. The temp bypass is not a good idea except for troubleshooting. You can also burn a hole in a piston. Check your ECU/ECM plug carefully. There are 2 ground wires to the ECU/ECM. black with a white tracer and another black only wire. If you haven't make sure both these wires have a good ground.
 
Which method did you use to verify the ECU ground is intact??

Specifically I would take a 55watt bulb and use it as a load. Connect one side of bulb to the Battery POS. Use a paper clip, drill bit, or something that fits into the female socket.

Your electrical path is Battery Positive - though 55 watt light - and into the ECU Black ground wires.
This loads the wires with 3 to 4 Amps lighting the light.

As added proof about the ground wires integrity, use your volt meter and place it on Battery NEG and the ECU GROUND WIRE WHILE the lamp is connected at the harness. You are reading loss across the wire if the voltage is measurable.

By applying a load AND reading the voltage (We expect zero volts) we have proven the wire to be good ground. Use this setup to test the other two grounds.

Mind you KEY is OFF and the ECU is removed from the harness for the tests above. Maybe take a picture of your set up taking note that the WIRE size used for test leads CAN impact test results. Too small of conductors and the wires heat up and drop voltage giving you bad information. Use something like 16 to 18 gauge wires for testing a 55 watt lamp.

NEW TOPIC: NEW TEST - Have you tested the power to the ECU when the Key is ON?
 
Last edited:
Is there any way to check the ecu? To make sure it isn't bad?

Have you verified the ECU has both of it's grounds working? :confused:

You might hopefully find a used working ECU and see if that fixes the problem but if you have lost ground integrity another ECU will not cure the problem.
 
Last edited:
Finally got back around to messing with the bike again and its pulling some diagnistic codes it hasnt pulled since the problem started. Its pulling 13, 15, and 43

15 and 43 both say it could be from fualty ECU. So the best thing I could probably try to do is find someone near me that would let me use their ECU to see if the bike will run? Could be tricky to find someone that will let me but I am going to try. Does an R6 ECU happen to work for an fz6 as well? thanks
 
Finally got back around to messing with the bike again and its pulling some diagnistic codes it hasnt pulled since the problem started. Its pulling 13, 15, and 43

15 and 43 both say it could be from fualty ECU. So the best thing I could probably try to do is find someone near me that would let me use their ECU to see if the bike will run? Could be tricky to find someone that will let me but I am going to try. Does an R6 ECU happen to work for an fz6 as well? thanks

If there was a ground problem, there are 2 grounds, you can still throw codes. Have you had a chance to test the 2 grounds for continuity?

Randy:popcorn: Scott:popcorn: Clif:popcorn:...........sound of crickets..........
 
Last edited:
43 - The ECU is unable to monitor the battery voltage (an open circuit in the line to the ECU). Power supply to the injectors and the fuel pump is not normal.

PS power supply does not mean just the +12v pos input. Supply means both power and ground.

Or properly load test the ground wires as suggested!!!!!!!!?
ECU does not swap from R6.
 
Back
Top