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Discussion Starter #1
OK, first of all thanks for the help with my other questions. I fixed my starting issue with the decompression spring I installed today. Put everything back together, turns over awesome now! Fixed cut wires going to FI light in dash. Tried grounding wire to battery ground to read codes with machine not running. Didnt read any codes at all! Thought that was a good thing. IT WONT START? Has new plug, awesome spark with reistance tester. Awesome fuel pressure at injector, no gas coming out of injector. Performed test procedures in manual, Ref signal was right with 3 seconds of battery voltage then 0. Same with Return signal to Computer. Resistance was within spec at around 11.6 ohms. Rigged up a test light, aligator clip, wire and flat connectors, and hooked up to injector, its clicking each time I complete the circuit to battery. That leads me to believe the injector is working? Or can it still be bad? The computer harness will not make it click( pulse). All other tests seemed to be right on with voltage. What is going on? I kinda stumpted. Thanks for any help, you guy seem to have an anser for everything so far.
 

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I have a list posted here somewhere of the things that will turn your injector off.

Otherwise bad injector if you have it hooked up and in your hand and it is not spraying.
 

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Make sure the roll over sensor is ok?
 

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Check your overturn sensor under your hood, it might have fallen off the bracket...service manual chapter 3-56...

Also fuel injector service manual chapter 3-58~61...

Need a service manual PM me with your email address and I'll send you one...??
 

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Discussion Starter #5
Guys, I have the front fenders off, checked roll over sensor, it was in its place, took out and it rattled, seemed to be fine. Check through Chapter 3 on Injector, all tests seemed to be correct, Voltage into Injector was good at 12v for 3 seconds, then 0, same on return signal wire. As manual states it should be. Resistance accross injector was withing spec as stated at around 11.6 ohms. Pressure is good right up to injector. The injector clicks when hooked up to battery power as one of the other tests state. Can the injector still click, and be bad, because the signals voltage seem right. It did have a severe miss last time out, almost like the gas was just cut off, but then it would take off normally again. Was that the injector on its way out? Ill look around for posting with reasons for injector not working. Hate to order a new injector, and have it be something else. Though i cant seem to believe it would be anything else. Thanks again.
 

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Discussion Starter #7
I dont know anyone with a KFX450R, Is there any way to test the ECU? I really cant afford one of them. How can it be bad if its giving the right reference voltage to injector and the return voltage is correct? I went to school for automotive and feel pretty confident about working on most things but this is really making me want to just bring it to a Kawi dealer, which is about 60 miles away. Fuel injection is awesome when working otherwise a pain in the A$$. Wish it would magically start working.
 

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Read every word on 3-37 of the service manual (pdf pg 97).

If you put the test light in place of the injector and crank the quad over does the light flicker?
Service Manual 3-59 (pdf pg 119)

Does the injector click during crank over?


I mean it sounds like a bad injector and I hope it is nothing more serious
 

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I dont know anyone with a KFX450R, Is there any way to test the ECU? I really cant afford one of them. How can it be bad if its giving the right reference voltage to injector and the return voltage is correct? I went to school for automotive and feel pretty confident about working on most things but this is really making me want to just bring it to a Kawi dealer, which is about 60 miles away. Fuel injection is awesome when working otherwise a pain in the A$$. Wish it would magically start working.
Check your ignition coil for spark...!!!

Are you getting spark?
 

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Discussion Starter #10
Great spark! Brand new plug plus tested with automotive resistance spark tester and sparked awesome with that too.
 

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Discussion Starter #11
Duster, when I remove injector and hook up as in book with jumpers, bulb, and connectors to a battery, each time I completed the circuit the injector would click. Yet it does not click when hooked up in wheeler connected to harness. Again the input voltage is correct along with output. Resistance accross injector is right. Fuel Pressure is great right up to the injector, spark is great, FI light comes on when key first turned on then shuts off, tried grounding and checking codes, nothing flashed accross light at all. Battery is at 12.6v. Can I just run power to injector directly while still hooked up to fuel line, and try to manually get the injector to click( pulse) If it sprays its prob good right? THen its more than likely what? ECU, o boy. Hope not. Let me know if this makes sense to you guys. Thanks
 

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Great spark! Brand new plug plus tested with automotive resistance spark tester and sparked awesome with that too.
Have you pulled the injector and check if it's misting fuel...

leave it hooked up, point it away from you and hit the starter button...??

misting it's good, if it squirts with drops or dribbles it's bad...
 

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You can jump the injector directly off the battery, 2 wires for positive and one for ground.. Like said, it should be a steady stream of gas coming out.. Before buying anything, be sure to check all your wiring.. I had a broken fuel reserve wire, that caused the injector not to work.. Check from the harness to the injector,the wires under the battery and under the hood..
 

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Discussion Starter #14
Update: Injector hooked directly to battery power sprays gas. Does not when hooked to harness. Wheeler fires right up with a little shot of starting fluid. Double checked voltages to injector, it was still 12 v for three seconds, same for return voltage. Tried it with ECU unplugged, No go. Tried with rollover sensor unplugged, still nothing. I am lost, this thing makes no sense. Whats next, I cant afford to start throwing parts at it. I dont have any buddies with the same wheeler either, to swap parts. Any other ideas now??
 

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Focus your attention on the overturn sensor, Your troubles began when you tipped it over on it's side...Correct?

You overturn sensor won't reset...!!!

Turn the key on/off to reset...

Vehicle-down Sensor Output Voltage
Connections to Sensor Connector
Meter (+) → Y/G lead [D]
Meter (–) → BR/BK lead [E]

Output voltage on the Y/G 3.7~4.1 volts...

What is your sensor's output voltage...?????
 

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Discussion Starter #17
I guess I am going to try to check pwr and ground continuity to ecu. This thing has much too many wires to deal with. I am running out of options though, I sure hope its not the ecu.
 

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I guess I am going to try to check pwr and ground continuity to ecu. This thing has much too many wires to deal with. I am running out of options though, I sure hope its not the ecu.
If the pwr/ground check out on the ECU...???

Here's the F.I circuit...http://www.frewracing.com/users/boys/Data/InfoFiles/kfx450r/fuelinjectorcircuit.jpg?20120210190341

Check the continuity of the BL/R (injector pulse) wire back to the ECU on the injector wire...If good then I'd focus on the ECU for being bad..

Here's a replacement ECU that many here are using...$55.00. It's adjustable but defaults to the OEM settings...
eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices
 

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Discussion Starter #19
Dust Devil, I just checked continuity between harness that plugs into ecu. Have good continuity on both wires going back to harness that plugs into ecu. I checked for power on terminals specified in manual. There is no power there on either on terminal 13 or 29. Dont matter if key is on or off. Should it still be hooked up to ecu to perform this test? It doesnt specify. If so how can I use the paper clip to test it? Main fuse has good continuity. Where does the power come from to the harness? From where the main fuse is? Or from a relay? Still trying to hold on to some hope for the ecu to be ok. I will check continuty of terminals 21 and 25 next to see if there is good ground to harness. Ill get back to you shortly. Going back and forth from computer to garage.
 

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Discussion Starter #20
Link didnt work to ebay. Thanks for the link though, maybe I can find it by searching, still hope its not ecu.
 
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