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Low injector duty cycle on power FC

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Old Apr 4, 2007 | 08:22 PM
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Low injector duty cycle on power FC

Just put in a new walbro pump , ( thanks Ihor) and now im seeing max duty cycles on the commander of 45-47%.


I ran a search and read for hours but everything is for going over like 95-100% duty cycles.


So im thinking that they are stuck shut. Or going bad ie: not spraying.

I know there is some kind of test to do with a 12v. line attached to them and listen for a clicking noise. But I really don't want to break ****. If I don't do this right.

Also when im at like 100 and gun it I feel like the engines just rev.s high and doesn't move anymore. Then I let off the gas real quick.


Should my duty cycle be higher?


Thanks for the input.
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Old Apr 4, 2007 | 09:37 PM
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??anyone
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Old Apr 4, 2007 | 11:05 PM
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Semper Fi...

How much boost, what size injectors?
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Old Apr 5, 2007 | 07:32 AM
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10psi stock injectors.

Semper Fi.
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Old Apr 5, 2007 | 09:26 AM
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Rent, borrow or buy a wide band to find out what's going on with respect to a/f ratio's.
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Old Apr 5, 2007 | 10:14 AM
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Why would changing out the fuel pump affect duty cycle? Duty cycle is primarily determined by rpm and boost. There are a few other things that can affect it such as water or air temperature, but I can't see how the fuel pump has anything to do with that. I guess you are just reading it off the commander. What rpm and boost are you at when you see 45%-47% duty cycle?
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Old Apr 5, 2007 | 10:26 AM
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rynberg's Avatar
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Duty cycle is based on the fuel maps and injector flow rates, it has nothing whatsoever to do with fuel pumps or physical condition of the fuel system.

Your other problem is a slipping clutch.
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Old Apr 5, 2007 | 10:30 AM
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If your questioning your injectors I would just send them out for flow balancing and cleaning at either wichhunter or rc engineering. Its pretty cheap and will make sure theyre in tip top shape before they cause a lean situation and pop your motor.
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Old Apr 5, 2007 | 10:46 AM
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Yes, Cgotto6 . I think I will pull them to get inspected. Thanks for the help guys.
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