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Old July 24th, 2019, 04:11 PM   #1
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2014 M796 Injector issue

Friend bought a 796 that won't start. It's having a weird injector issue and hasn't ran in a long time it seems. The bike only shows 700 miles on the dash.

Things i have checked. Battery fully charged outside of bike(tried 2 batteries.
Bike cranks strong with good compression H: 166PSI V: 168PSI cold.
both spark plugs are firing and dry(leads me to fueling issue)

No codes showing in jpdiag software.

Fuel pump primes when keyed on. I pulled the pump assembly anyway to make sure the hoses aren't split or disconnected.

Fuel definitely gets to the injectors. I accidentally keyed on with the injectors removed and fuel poured out of the lines. Even with low fuel pressure I would think the injectors would spray weakly.

Here's the weird part. When i key off and on then hit the starter, the horizontal injector fires once and that's it. I can't really see the vertical injector due to the angle. It will do this every couple times keying off and on. I pulled the injectors and applied 9v to the terminals and both injectors clicked. I used a mechanics stethescope to confirm both injectors are clicking while cranking the bike.

I poured a small amount of fuel into each intake and the bike ran for a bit so its definitely something with the injectors.

I got a used set of injectors that also click while cranking but won't spray gas at all.

I'm thinking clogged injectors? its weird that they click while cranking but wont spray fuel. Also, the horizontal injector sprays once when first cranked which is strange.

Any suggestions?
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Old July 24th, 2019, 05:32 PM   #2
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Take the injectors to a injector specialist for cleaning. Probably a place not too far away? With all the injected vehicles, it is getting more common to have done. Yes, they might be dirty. If they are, then make sure to replace the fuel filter!!! The filter element breaks down over time.

If the injectors turn out to be clean, i would look for insufficient voltage to the injectors. The relay supplies power, the ECU supplies ground. Bad relay? Corrosion at the grounds?
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Old July 24th, 2019, 05:34 PM   #3
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Quote:
Originally Posted by keitih89 View Post
Friend bought a 796 that won't start. It's having a weird injector issue and hasn't ran in a long time it seems. The bike only shows 700 miles on the dash.



Things i have checked. Battery fully charged outside of bike(tried 2 batteries.

Bike cranks strong with good compression H: 166PSI V: 168PSI cold.

both spark plugs are firing and dry(leads me to fueling issue)



No codes showing in jpdiag software.



Fuel pump primes when keyed on. I pulled the pump assembly anyway to make sure the hoses aren't split or disconnected.



Fuel definitely gets to the injectors. I accidentally keyed on with the injectors removed and fuel poured out of the lines. Even with low fuel pressure I would think the injectors would spray weakly.



Here's the weird part. When i key off and on then hit the starter, the horizontal injector fires once and that's it. I can't really see the vertical injector due to the angle. It will do this every couple times keying off and on. I pulled the injectors and applied 9v to the terminals and both injectors clicked. I used a mechanics stethescope to confirm both injectors are clicking while cranking the bike.



I poured a small amount of fuel into each intake and the bike ran for a bit so its definitely something with the injectors.



I got a used set of injectors that also click while cranking but won't spray gas at all.



I'm thinking clogged injectors? its weird that they click while cranking but wont spray fuel. Also, the horizontal injector sprays once when first cranked which is strange.



Any suggestions?
The clicking noise tells you that they're not broken....they're definitely gummed up...700 miles in 5years... would be admirable if it was pushed up a hill that far... nonetheless your likely going to need a cleaner that uses pressure with them removed...keep at it..they will all clear eventually

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Old July 25th, 2019, 05:59 AM   #4
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Originally Posted by Svensken View Post
Take the injectors to a injector specialist for cleaning. Probably a place not too far away? With all the injected vehicles, it is getting more common to have done. Yes, they might be dirty. If they are, then make sure to replace the fuel filter!!! The filter element breaks down over time.

If the injectors turn out to be clean, i would look for insufficient voltage to the injectors. The relay supplies power, the ECU supplies ground. Bad relay? Corrosion at the grounds?
I didn't even think about the relay! I could see a failing relay only activating once in a while when keyed on. Grounds were the first thing i checked/cleaned.
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Old July 25th, 2019, 06:01 AM   #5
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The clicking noise tells you that they're not broken....they're definitely gummed up...700 miles in 5years... would be admirable if it was pushed up a hill that far... nonetheless your likely going to need a cleaner that uses pressure with them removed...keep at it..they will all clear eventually

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I swapped injectors and they both seem to spray once when I hit the starter after keying on and off maybe every 5 times. I'm leaning towards a relay/electrical issue.
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Old August 1st, 2019, 07:38 AM   #6
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Swapped the relays out and still the same problem. I think I'm going to find a place to have the injectors cleaned. I used jpdiag to run the fuel pump and fire the injectors. They click but won't spray. There's definitely fuel getting to the injectors because it'll spray when i remove the hose from the injector.
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Old August 1st, 2019, 08:26 AM   #7
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Swapped the relays out and still the same problem. I think I'm going to find a place to have the injectors cleaned. I used jpdiag to run the fuel pump and fire the injectors. They click but won't spray. There's definitely fuel getting to the injectors because it'll spray when i remove the hose from the injector.
might try your local Auto parts store to see if the have a fuel injector cleaner kit for rent

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Old August 8th, 2019, 04:28 PM   #8
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turned out to be clogged injectors, fuel filter and fuel pump dying. The bike must have been sittng for a long time. I sprayed some carb cleaner through the injectors using the straw and made an adapter to fit around the end of the injector. It barely sprayed anything through. I back flushed it and then flushed it the normal direction. I finally got a good spray pattern with both injectors. I put it back on the bike and fuel sprayed very weakly. I pulled the fuel filter and it was very restricted. I could blow through it but it was obviously gummed up. Changed the fuel filter and still a weak spray. I put a spare fuel pump in and it fired right up. I'm guessing the pump was getting weak or gummed up along with the filter and injectors.
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