rbgetz

Probably a newbie question since I am new to jets. I just started my new K-120 and getting familiar with it all. In the pump start menu the manual says default if AUTO+2, but my is set at AUTO+1... Not sure it matters, but it really doesn't explain what the number is doing. What's the difference between going from +1, +2, ...?? I had a little bit of a wet start the first time, but otherwise fine. Rob

gunradd

My Feedback: (9)

Hello Rob.

Pump auto 1 is ok. Factory probably got better starts with that engine-pump combo on auto 1. Every engine and pump are different. The manual is a great place to start but not the exact settings most use.

This is straight from the Xicoy ECU manual.
Pump Start point: Sets the power of the pumpwhen it is started at beginning of the fuel ramp.The FADEC have the ability of to automatically adjust the pump power to start it at thelowest possible speed, independently of the battery voltage and pump roughness. Also theuser has the possibility to adjust the minimum pump power manually.AUTO mode: The values of “Pump start point” from 0 to 8 are in AUTO mode.This means that the FADEC will adjust itself the pump power to start it slowly bymeasuring the voltage generated by the pump motor. The usual value for an unknown engineis AUTO+2, but after the first start you can increase or decrease the fuel flow if needed.

rbgetz

Hi Gunradd, thanks for the insight. I've been having a few wet starts with fuel dripping from turbine tail cone on startup. Is there any suggested start up setting I can adjust to help prevent this? I didn't want to mount in fuse yet.

George

My Feedback: (57)

You need to try to figure out which "phase" of the start is causing the drip (which can be difficult sometimes). In my experience the Pump PW Ignition and Preheat Fuel are usually the parameters that need adjusting depending on which is causing the excess fuel at start, BUT not limited to just those two. I'm merely suggesting them as a starting point if you don't know which is causing your drip.

My 120 settings for Kero with no drip/s are:
AUTO+2
005
7.4V
7.0V
100
160
15,000 RPM
19,000 RPM
18,000 RPM
2,000 RPM
022
80%
100C
5,000 RPM
10,000 RPM
25%
30 s
AUTO-KERO

I'll be running diesel in a couple weeks so I'm anticipating a slight change in parameters when I switch.

rbgetz

Hi George, I'm going to check my parameters against these. I am running Diesel. I'll let you know what they're set at now. Rob

George

My Feedback: (57)

I can also let you know my numbers on diesel in a couple weeks.

Remember, some of your numbers will change according to elevation and very cold and/or hot ambient temperatures.

rbgetz

Your numbers are on the left and mine on the right. only two differences..The FP start point, but the biggest difference is on the "Start Power on fuel Ramp".. yours being 160 and mine at 220.

[TABLE="width: 481"]
[TR]
[TD]Fuel Pump Start Point
[/TD]
[TD]AUTO+2
[/TD]
[TD]AUTO+1
[/TD]
[/TR]
[TR]
[TD]Pump start ramp
[/TD]
[TD]5
[/TD]
[TD]5
[/TD]
[/TR]
[TR]
[TD]Glow plug power
[/TD]
[TD]7.4V
[/TD]
[TD]7.4V
[/TD]
[/TR]
[TR]
[TD]Low batt. Volts
[/TD]
[TD]7.0V
[/TD]
[TD]7.0V
[/TD]
[/TR]
[TR]
[TD]Start power at ignition
[/TD]
[TD]100
[/TD]
[TD]100
[/TD]
[/TR]
[TR]
[TD]Start Power at fuel ramp
[/TD]
[TD]160
[/TD]
[TD]220
[/TD]
[/TR]
[TR]
[TD]RPM 100% starter power
[/TD]
[TD]15,000 RPM
[/TD]
[TD]14,000 RPM
[/TD]
[/TR]
[TR]
[TD]RPM OFF starter
[/TD]
[TD]19,000 RPM
[/TD]
[TD]19,000 RPM
[/TD]
[/TR]
[TR]
[TD]RPM to reconnect starter
[/TD]
[TD]18,000 RPM
[/TD]
[TD]18,000 RPM
[/TD]
[/TR]
[TR]
[TD]RPM IGNITION K.
[/TD]
[TD]2,000 RPM
[/TD]
[TD]2,000 RPM
[/TD]
[/TR]
[TR]
[TD]Pump Pw Ignit. K
[/TD]
[TD]22
[/TD]
[TD]22
[/TD]
[/TR]
[TR]
[TD]Engine min. Flow
[/TD]
[TD]80%
[/TD]
[TD]80%
[/TD]
[/TR]
[TR]
[TD]EGT End Preheat:
[/TD]
[TD]100C
[/TD]
[TD]100 C
[/TD]
[/TR]
[TR]
[TD]RPM PREHEAT K
[/TD]
[TD]5,000 RPM
[/TD]
[TD]5,000 RPM
[/TD]
[/TR]
[TR]
[TD]RPM Fuel Ramp K
[/TD]
[TD]10,000 RPM
[/TD]
[TD]10,000 RPM
[/TD]
[/TR]
[TR]
[TD]Preheat fuel:
[/TD]
[TD]25%
[/TD]
[TD]25%
[/TD]
[/TR]
[TR]
[TD]Ignition TimeOut
[/TD]
[TD]30 s
[/TD]
[TD]30 s
[/TD]
[/TR]
[TR]
[TD]Start Mode:
[/TD]
[TD]AUTO-KERO
[/TD]
[TD]AUTO-KERO
[/TD]
[/TR]
[/TABLE]

George

My Feedback: (57)

I have never messed with that parameter so I can't really help there, but I can tell you with some certainty that if you have the same numbers I'm using for Kero, you're going to be "rich" starting on diesel.

I like a very slow starting engine so I tend to lower the numbers that give me the "softest", but most reliable starts on diesel; and this always requires some testing. I also like doing my testing on a "cold" engine, and can take some time, but that is my personal preference; and I like doing it "insitu".

If you haven't gotten it figured out by the time my BobCat arrives, I'll let you know what numbers I come up with.

gunradd

My Feedback: (9)

To me it looks like you have it set up for Kero not diesel.

Try these settings.

Pump PW ign 19
Preheat fuel 23

Also like George said let us know when you get the drip. If its right in the begining of the start then Pump PW ign is to high. If its in the middle then Preheat fuel is a little rich.

rbgetz

Got little better results. I made the changes: Pump PW ign 19 & Preheat fuel 23%. Also changed "start power at fuel ramp to 190. I got a clean start no dripping at preheat like before. but then during the Fuel Ramp phase I saw a few drops come out the tail cone. Not enough to drip, but just enough to flow back down the tail cone to the engine and slowly burn off. I'm assuming I'm running a little too rich.

gunradd

My Feedback: (9)

Getting closer. I suspect that little drip is left over from preheat even though it came out during ramp. Try and lower preheat by 1 or 2 and try again. If you get preheat to low the engine will hang during the preheat phase.

George

My Feedback: (57)

+1

rbgetz

I think just a little more fine tuning and I'm there. I lowered preheat fuel down to 21%. Seemed to take a little longer to ignite, but didn't hang. still had some exterior fuel present during FuelRamp. But on a warm start all went just fine, no fuel drips during fuel ramp and noticed that the RPM's ramped nicely to idle with no overshoot.

gunradd

My Feedback: (9)

Think I would leave it alone now. Sounds good. As long as it's not pooling up under the engine. Now go burn some fuel have fun!

rbgetz

Thanks for the help! Going to be mounting it in a new Tomahawk Futura 1.9m I'm just finishing up on.

George

My Feedback: (57)

Yes, this has been my experience. I always try to get a good start on a "cold" engine because warm engine can mask some "rich" conditions, but it does sound like you might be very very close.

rbgetz

Thanks George. on cold start, I get a little bit out the back when it's about midway through Fuel Ramp and RPM's around 15,000-17,000. once at idle nothing.

rbgetz

Thanks Guys! Mounted in airframe and ran fine today. A little weight and balance check, but now I have to wait for the snow to clear the runway!

Westwindpilot86

Gunradd, I sent you a pm.

Steven