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Discussion Starter · #1 ·
Will a faulty crank sensor cause the fuel pump not to cycle on when the key is switched on?
 

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Discussion Starter · #3 ·
That's what I figured but already checked both those and still no fuel pump cycling. I'm guessing the only thing left is the ECU...agree?

I had the quad on the dyno, tuning the Procom for a big bore kit and head porting. It was making the 3rd pull and just went dead then powered back up. I shut it off and when I tried to fire it back up, no fuel pump cycling. Lights (FI for 3 seconds, and neutral) come on, it turns over but won't start.
 

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That's what I figured but already checked both those and still no fuel pump cycling. I'm guessing the only thing left is the ECU...agree?

I had the quad on the dyno, tuning the Procom for a big bore kit and head porting. It was making the 3rd pull and just went dead then powered back up. I shut it off and when I tried to fire it back up, no fuel pump cycling. Lights (FI for 3 seconds, and neutral) come on, it turns over but won't start.
Run 12v to the fuel pump to make sure.. It could be a bad connection to the or a bad fuel pump..?

Or check if you have 12v at the fuel injector..? see pictures
 

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Discussion Starter · #5 · (Edited)
I had already ran 12v to the pump and it worked fine.

I checked continuity on the r/wh wire from the relay to the fuel pump to the injector...good

The r/wh wire is the power to the pump and injector. I don't understand how it's "energized"? There is a "door" (contact) shown on the relay drawing. There is power on the other side of the contact but what makes the contact close to get power to the red/white wire?
 

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I had already ran 12v to the pump and it worked fine.

I checked continuity on the r/wh wire from the relay to the fuel pump to the injector...good

The r/wh wire is the power to the pump and injector. I don't understand how it's "energized"? There is a "door" (contact) shown on the relay drawing. There is power on the other side of the contact but what makes the contact close to get power to the red/white wire?
Make sure your battery is fully charged,,12.8v standard..

Do you have spark..?

Switch your pump relay with one of the other relays & see if that works...!

Stock ECU has a self diagnostic circuit...The Procom (Does not)... !!

Plug in your stock ECU if you have it.. Try starting motor does the F.I light remain ON or turn off after 3-seconds...?
 

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Discussion Starter · #7 ·
Battery is at 13.5 volts and always on battery tender when not using

Cannot confirm spark right now. I have new stator/crank sensor coming due to bare wires I found when looking for solutions. That was the reason for originally starting this thread...lol

Swapped out relay with a new one I have and also with one of the others...no fuel pump

Plugged in stock ECU and no difference. (FI light comes on for 3 seconds then off)

It almost seems like the rollover sensor or some other "safety" feature is activated but I've swapped out the roll-over sensor and soldered the kill button wires together previously. (I use a tether for racing) Could there be other items which would interrupt the start sequence?
 

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Battery is at 13.5 volts and always on battery tender when not using

Cannot confirm spark right now. I have new stator/crank sensor coming due to bare wires I found when looking for solutions. That was the reason for originally starting this thread...lol

Swapped out relay with a new one I have and also with one of the others...no fuel pump

Plugged in stock ECU and no difference. (FI light comes on for 3 seconds then off)

It almost seems like the rollover sensor or some other "safety" feature is activated but I've swapped out the roll-over sensor and soldered the kill button wires together previously. (I use a tether for racing) Could there be other items which would interrupt the start sequence?
If no code is showing up, then your crank sensor is fine...Code 21 see picture

It's not the crank sensor preventing your fuel pump turning ON, it could be an ECU pin (19) / bad connection into the harness connector.. see picture
 

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Discussion Starter · #9 ·
I'm leaning toward replacing the ECU or contacting Procom to see if they will warranty it, but it's been over a year.

I have the stock ECU which came with the quad when I bought it, but I just don't know if it's any good. (I did install that stock one but got the same results) This would confirm if its the ECU or not. I just need to find someone who could install it on their working KFX to verify.
 
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