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Replacing fuel injectors 2002 f4i

  #1  
Old 08-16-2016, 12:13 AM
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Default Replacing fuel injectors 2002 f4i

Today I tested my fuel injectors to determine which needed to be replaced. When I did the test, I found the 2 on the throttle side sprayed more gas than the 2 on the clutch side. My bike has always run rich, was sluggish in the lower rpms and the spark plugs are black and were wet when I pulled them. My issue is I do not know which 2 fuel injectors need to be replaced. Any help would be very appreciated.

Also if it matters I have already checked the fpr and it is dry as a bone.

Thanks
 
  #2  
Old 08-16-2016, 10:19 AM
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What you need to know is:
Are the injectors supposed to be matched? In an inline-4, I'd think so but verify to be certain. Then you can adjust the flow with an aftermarket tuner. Perhaps some of them allow adjustment on an individual cylinder (I don't know, I've been out of the game for awhile and don't know what the latest gizmos can do).
 
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Old 08-16-2016, 11:50 AM
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I'd replace them all if you have 2 bad ones. They are all of the same age and operated in the same conditions as the ones that failed.

They are not matched and there is no adjustment, other than electronically setting the pulse width. They are merely open/close valves with a tip to atomize the fuel.
 
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Old 08-16-2016, 01:48 PM
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Originally Posted by 74demon View Post
I'd replace them all if you have 2 bad ones. They are all of the same age and operated in the same conditions as the ones that failed.

They are not matched and there is no adjustment, other than electronically setting the pulse width. They are merely open/close valves with a tip to atomize the fuel.
In a production run they'll be some manufacturing tolerances that may pass spec. Serious engine builders (race builders) match components as much as possible beyond what comes from the factory. They may test dozens of injectors to get 4 that work well together.

These guys made a business out of it in aircraft piston engines when the data was very controversial (and still is) and now many people swear by the techniques.
General Aviation Modifications, Inc.
 
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Old 08-16-2016, 02:14 PM
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Originally Posted by Jaybird180 View Post
In a production run they'll be some manufacturing tolerances that may pass spec. Serious engine builders (race builders) match components as much as possible beyond what comes from the factory. They may test dozens of injectors to get 4 that work well together.

These guys made a business out of it in aircraft piston engines when the data was very controversial (and still is) and now many people swear by the techniques.
General Aviation Modifications, Inc.
I'm sure the race guys do. This is a production bike, and an old one at that. They bought them by the lot and put 4 in each bike. Flow testing complete.

4 new clean ones will be better than 2 old half plugged and 2 new.
 
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Old 08-16-2016, 02:35 PM
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Originally Posted by 74demon View Post
I'm sure the race guys do. This is a production bike, and an old one at that. They bought them by the lot and put 4 in each bike. Flow testing complete.

4 new clean ones will be better than 2 old half plugged and 2 new.
You're right, as usual. I'm wondering if the injectors can be cleaned and salvaged, saving the OP and everyone who reads this thread some valuable coin that then can be turned into gasoline.
 
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Old 08-16-2016, 02:48 PM
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The OP claims he has either 2 leaking or 2 partially plugged. If he has the time to waste in an attempt to save a few bucks, he could take them out and give them a soak in some kind of cleaning product. They can't be taken apart, so how clean the inside would get would be a mystery. If it's the case of 2 leaking, no amount of cleaning will fix the bad internal seals..

I would also replace the fuel filter....
 
  #8  
Old 08-17-2016, 03:24 PM
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I'd send all 4 injectors to Melka and let him clean and flow test each one. Its only like $40 or something really reasonable like that. http://www.proflowtech.com/fuel-inje...aning-service/
 
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