Bad injector ground

[b.polley11]

Ive got a 2009 fz6. Had to get the tank repainted and while it was off I repainted the frame because the previous owner painted red stripes on it. Went to put everything back together and it wont stay running unless I use starting fluid. It will barely idle for a couple seconds and then turn back off. Started replacing fuel pump and a few others.....nothing. Pulled the injectos and cleaned them, put fresh gas, changed spark plugs, etc. Then went to make sure injectors were getting power when I was cranking it over with a test light and BAM it started. Pulled the test light off the wire and it died. So somehow I have a bad ground and cant seem to find out where or which one, any ideas where to start?

 

[FinalImpact]

Did you pull the engine from the frame?

The ECU is the ground. The injectors have power through a Red /blue trace which goes to the fuel pump. Power comes from the Starting Circuit Cut-Off relay under the left pod.

Tell us exactly how and where you had the test lead connected.
If from battery positive to the fuel pumps Red/blue trace, the incandescent bulb in your test lamp gave everything power.
Is this how you used the test lamp?

The ECU has at least two grounds (Black wires) that need verified.
You also need to verify the side stand, clutch lever, and neutral safety switches all work.

 

[b.polley11]

Did you pull the engine from the frame?

The ECU is the ground. The injectors have power through a Red /blue trace which goes to the fuel pump. Power comes from the Starting Circuit Cut-Off relay under the left pod.

Tell us exactly how and where you had the test lead connected.
If from battery positive to the fuel pumps Red/blue trace, the incandescent bulb in your test lamp gave everything power.
Is this how you used the test lamp?

The ECU has at least two grounds (Black wires) that need verified.
You also need to verify the side stand, clutch lever, and neutral safety switches all work.

Engine stayed in the frame.

Had the test light on the battery negative and when I touched it to one of the wires that were plugged into the injectors it would stay running, but the moment I took them apart it would die.

I will go check the 2 ECU grounds. Any way you reccomnd to check the switches?

Thanks

 

[FinalImpact]

Key On. Verify clutch switch has power to black wire/red trace, ~ battery voltage when the Clutch lever is out. The Black/yellow trace should also have power.
Very green Neutral comes on in N and off when in gear.
With left side pod off, find the light blue wire/green trace into the starter circuit cut-off relay.
Move the side stand down. Insert probe. You should see battery voltage until the side stand is moved up.

Do you have a hand held meter or just a test light?

 

[b.polley11]

When i touch the test light from the battery ground to ANY injector wire the bike will stay running and rev up like normal. So I am assuming that since I am grounding the injector leads, that I have a bad ground.

Just hooked up test like to the battery positive and touched the two ECU ground wires and the bulb would light up. I assume that means a good ground?

 

[b.polley11]

just read this second reply, will go check switches now. thanks

HAve a hand held meter as well

 

[FinalImpact]

Note: I may have the clutch lever position reversed with reference to when the red wire has power.

Also, Im not seeing how your test lead on the battery Neg would help but I don't know which wire you touched. Ecu ground control for injector duty cycle both have black trace. If you ground them it could squirt a lot of fuel and make it run. But it would not run well. Be specific about what wire color was touched with test lamp. Thx!
Red/blue trace has battery voltage with battery ground as reference. Red black trace and green black trace would not light test lamp but could force injectors 1 & 4 or 2 & 3 to fire but not in a controlled manor... make sense?

 

[b.polley11]

Note: I may have the clutch lever position reversed with reference to when the red wire has power.

Also, Im not seeing how your test lead on the battery Neg would help but I don't know which wire you touched. Ecu ground control for injector duty cycle both have black trace. If you ground them it could squirt a lot of fuel and make it run. But it would not run well. Be specific about what wire color was touched with test lamp. Thx!
Red/blue trace has battery voltage with battery ground as reference. Red black trace and green black trace would not light test lamp but could force injectors 1 & 4 or 2 & 3 to fire but not in a controlled manor... make sense?

When I touch the red/black wire on injector 1 and 4 with test light on battery ground it runs. And same happens on injectors 2 and 3 when I touch the green/black wires.

The side stand was showing 0.51 until i put it up, then it dropped to 0

Neutral light works as it should


I am fine mechanical wise but once it gets to electrical, its not my strong suit. so if it seems I am doing something wrong just let me know

 

[FinalImpact]

From the top.
What all was disconnected for repairs?
What all was replaced without success?

It has always cranked with starter button press but does not run. Is that true? And you hear the fuel pump prime when key is first turned on?

Please use meter and measure battery voltage everything off.

Run switch On, trans in Neutral.
Key on measure battery voltage.
Key on measure red/blue trace at injector.
Key on measure red/black trace at either ignition coil.

Key off with test LAMP connected to battery POS, touch black wire on fuel pump. Unplug from pump for easy access. Lamp should light.

Disconnect Battery Ground!
Unbolt ecu and unplug connector. Inspect pins for signs of damage. With test lamp on batt POS touch each of the black wires in the harness to the ecu. Lamp should light.

Unplug the starter circuit cut off relay (SCCOR). Look for damage to pins.... Also verify ign fuse in RS pod. Im sure its fine but look anyway.

Clarify; when you say it runs, how long, all cylinders, and if you twist the throttle does it follow along and rev or what does it do?

 

[b.polley11]

From the top.
What all was disconnected for repairs?
What all was replaced without success?

It has always cranked with starter button press but does not run. Is that true? And you hear the fuel pump prime when key is first turned on?

Please use meter and measure battery voltage everything off.

Run switch On, trans in Neutral.
Key on measure battery voltage.
Key on measure red/blue trace at injector.
Key on measure red/black trace at either ignition coil.

Key off with test LAMP connected to battery POS, touch black wire on fuel pump. Unplug from pump for easy access. Lamp should light.

Disconnect Battery Ground!
Unbolt ecu and unplug connector. Inspect pins for signs of damage. With test lamp on batt POS touch each of the black wires in the harness to the ecu. Lamp should light.

Unplug the starter circuit cut off relay (SCCOR). Look for damage to pins.... Also verify ign fuse in RS pod. Im sure its fine but look anyway.

Clarify; when you say it runs, how long, all cylinders, and if you twist the throttle does it follow along and rev or what does it do?

I am about to head off to work so when I get home I will check all that out and let you know.

Thanks

 

[Motogiro]

Interesting that the ECU seems to be the deciding factor in this. At first look we might think of this circuit in terms of DC but in fact the ECU may be making a logic decision based on that small current through the test lamp. It may not want to run until, "The Fat Lady with the Theremin Sings" It does look like a ground related problem but it may not be in the sense of DC but rather RF (radio frequency) Make sure the ground wire at the fuel pump wire goes to a good secure ground that is in no way through the fuel tank itself. The schematic shows 2 separate grounds for the ECU. This is an interesting trouble shoot...

 

[FinalImpact]

When i touch the test light from the battery ground to ANY injector wire the bike will stay running and rev up like normal. So I am assuming that since I am grounding the injector leads, that I have a bad ground.

Just hooked up test like to the battery positive and touched the two ECU ground wires and the bulb would light up. I assume that means a good ground?

One would like to assume that. Lets compare test methods.
A hand held meter testing voltage at the end of wire draws literally NO current. You could have a wire with 50 strands and 47 of the strands broken and your voltage as seen by a meter would appear good!

Lets say we use test lamp at that same point. An incandescent bulb draws current. Id guess just a couple watts. It is much more current than our metter takes but it still may not tell us our wires are broken just becuase it lights.

So, when faced with checking the integrity of a wire we need to load the wire to be tested such that it imposes about the same load as the device it is supposed to operate. Here we can improvise and use a bigger light bulb. One that draws more current. Like a brake light bulb. Or for a short test a 55watt headlight bulb.

If our fuel pump ground to battery POS terminal can power an H1 bulb for second, its very likely it can power the fuel pump.

So you get creative and find ways to isolate sections and test them.

That said, usually damaged wires will have increased resistance that can be measured with an Ohm meter on its lowest setting, but not always. The problem is the difference measured without a load is so small it goes un Noticed.

However as an example; measure from Batt NEG to 3 different ground points and lets say we read 0.3 ohms.
Then we measure our suspect lead wire and it measures 2.3 ohms.... that is a hint one would want to follow and do the load test as it is not like the others!!!

Or measure voltage drop when the wire is under load. A wire sized properly should not show much if any loss when loaded.
An example here is the battery as source reads 12.9 v but we measure the voltage from our battery to our functioning headlight and read 11.3 volts. That means we have loss and resistance. Time to inspect that run of wires, switches, relays along the way for a bad connection...

Does that mostly make sense?

 

[b.polley11]

From the top.
What all was disconnected for repairs?
What all was replaced without success?

It has always cranked with starter button press but does not run. Is that true? And you hear the fuel pump prime when key is first turned on?

Please use meter and measure battery voltage everything off.

Run switch On, trans in Neutral.
Key on measure battery voltage.
Key on measure red/blue trace at injector.
Key on measure red/black trace at either ignition coil.

Key off with test LAMP connected to battery POS, touch black wire on fuel pump. Unplug from pump for easy access. Lamp should light.

Disconnect Battery Ground!
Unbolt ecu and unplug connector. Inspect pins for signs of damage. With test lamp on batt POS touch each of the black wires in the harness to the ecu. Lamp should light.

Unplug the starter circuit cut off relay (SCCOR). Look for damage to pins.... Also verify ign fuse in RS pod. Im sure its fine but look anyway.

Clarify; when you say it runs, how long, all cylinders, and if you twist the throttle does it follow along and rev or what does it do?

Only thing I had to unplug was the gas tank. I put a new airfilter while the tank was off and put on new clutch and brake levers on the bars.

When I got the tank back and on the bike it would just turn over but wont start. It ran fine before. So i changed spark plugs, fuel pump (even though I could still hear the old one priming), air temperature sensor because it was pulling a code for that, cleaned injectors and still nothing.

It ran when I got the bike for a few months, just had some paint problems on the tank I was going to get fixed. Thats the only reason I had removed the tank. Yes I can hear the fuel pump priming.

To check the voltage with a multimeter I should just put the black plug on battery negative and red wire on whichever wire I am testing at the moment correct? just want to make sure I am doing everything correct

 

[IanHoots]

Yes I would be looking for voltage drop across the earth circuit between the ECU and the battery. In my past I have had issues with vehicles returned from panel shops with weird running problems that stemmed from poor reference voltage being supplied to the ECU. One of them was over-fueling when the earth wire was removed during chassis repairs, painted with over spray, then re-fitted. It looked right, but only made a partial circuit.

Honda S2000 is famous for this type of odd ball behaviour due to poor grounding

Try removing all earth wires, regardless of which part of the loom they are involved in, clean any paint etc off and guarantee good connection. Perhaps this will be quicker to diagnose by remove and re-check than with a test meter? Hopefully, because the bike has had some disassembly the problem will appear.

 

[FinalImpact]

To check the voltage with a multimeter I should just put the black plug on battery negative and red wire on whichever wire I am testing at the moment correct? just want to make sure I am doing everything correct?

-
Yes. And select DC volts.
Can you provide some detail on what was removed for Injector cleaning? You remove the whole Throttle Body and how did you clean the f/injectors?
-
Please verify ECU ground and the fuel pump ground. Most of these wires are moisture protected and not easily probed without penatrating the insulation. Some can be back-probed but it is not easy.
Hence suggesting opening the circuits and using a lamp to do a load test.

i.e. REMOVE battery POS cable. Unplug ecu, connect test lamp to battery POS post. Connect test lamp to Black grounds on both ecu and fuel pump. Lamp should light. It means your ground is good.
Use a brake lamp bulb if possible. If it lights bright, that is good.

You get the S2 FSM?

 

[b.polley11]

To check the voltage with a multimeter I should just put the black plug on battery negative and red wire on whichever wire I am testing at the moment correct? just want to make sure I am doing everything correct?

-
Yes. And select DC volts.
Can you provide some detail on what was removed for Injector cleaning? You remove the whole Throttle Body and how did you clean the f/injectors?
-
Please verify ECU ground and the fuel pump ground. Most of these wires are moisture protected and not easily probed without penatrating the insulation. Some can be back-probed but it is not easy.
Hence suggesting opening the circuits and using a lamp to do a load test.

i.e. REMOVE battery POS cable. Unplug ecu, connect test lamp to battery POS post. Connect test lamp to Black grounds on both ecu and fuel pump. Lamp should light. It means your ground is good.
Use a brake lamp bulb if possible. If it lights bright, that is good.

You get the S2 FSM?

All I did to remove injectors was unplug them and get the fuel rail loose. That gave me just barely enough room to squeeze the fuel injectors off of the fuel rail. Cleaned them by connecting them to a battery and rigging up carb and choke cleaner to spray through them, saw this on youtube

Sorry, I have been busy with work and havent had time to check much in the past day or 2 but am hoping to be able to get into it pretty hard this weekend to check all this stuff you guys recommended.

 

[b.polley11]

To check the voltage with a multimeter I should just put the black plug on battery negative and red wire on whichever wire I am testing at the moment correct? just want to make sure I am doing everything correct?

-
Yes. And select DC volts.
Can you provide some detail on what was removed for Injector cleaning? You remove the whole Throttle Body and how did you clean the f/injectors?
-
Please verify ECU ground and the fuel pump ground. Most of these wires are moisture protected and not easily probed without penatrating the insulation. Some can be back-probed but it is not easy.
Hence suggesting opening the circuits and using a lamp to do a load test.

i.e. REMOVE battery POS cable. Unplug ecu, connect test lamp to battery POS post. Connect test lamp to Black grounds on both ecu and fuel pump. Lamp should light. It means your ground is good.
Use a brake lamp bulb if possible. If it lights bright, that is good.

You get the S2 FSM?

Just checked ECU and fuel pump grounds exactly how you said with a test light and were showing bright light on bulb in test lamp

 

[FinalImpact]

You unplugged the ecu and didn't see anything strange?

The two most seen failures is the run stop switch goes bad and folks lift the tank pulling wires from the connectors at either the pump or sending unit.
Because the action for your was tank removal and the fix was current probe to unsuspecting locations, I am at a loss without more info!

When is the last time it ran proper?
Did you double check all work done?

I dont feel like retyping, please reread thread and answer all the questions you can - as the original fault and the current fix which makes it start, idle and (what else), doesn't add up.

Somewhere you have a bad connection whether it developed on its own or was induced, it needs found. Best way is by detailed inspection...

Also I would like to know if connecting your test lamp from Bat POS to injector power allows it to start, idle, and rev up.

 

[IanHoots]

It's a weird one thats for sure.

Yes, I would be disconnecting and checking every electrical plug on the bike.

 

[b.polley11]

Connecting test lamp from battery pos to injector positive Doesnt make a difference. Only when connected from battery ground to injector ground.

Just hooked up multimeter to the positive wire on injector plug and negative wire on the injector plug and turned the bike over to see how much power they were pulling, only showed at most .3
Should be reading way more correct?