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  #1  
Old 08-05-2017, 01:21 AM
Adriaan Kleyn Adriaan Kleyn is offline
 
Join Date: May 2016
Location: Hluhluwe, South Africa
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Default RV14 IO390 difficult to start

I struggle to start my RV14 IO390 cold or hot. I can't find a procedure that works consistently every time. With my Cessna 182 with a Lycoming IO 540 it is easy,when cold - throttle full forward, mixture full rich ,prime till you get a positive fuel flow, mixture fully lean, throttle 1/4 inch and crank. It will start immediately. When cold - throttle 1/4 inch, mixture fully lean, crank and catch with the mixture when it fires. It work every time and I have never had a flooded engine. With my IO390 it is very different story, since I've had a flooded engine several times as well as a flat battery. I have tried several different techniques but doesn't get consistent results. I need some advice.
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  #2  
Old 08-05-2017, 06:28 AM
Ron B. Ron B. is offline
 
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Location: Yarmouth, Nova Scotia
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I'm certainly no expert , but I find just the opposite with my I0-390 (RV-14A0 and the 0-540 in what use to be our RV-10. Only start issue I've had so far (knock on wood) is trying to re-start for fuel after shutting down for the night and not opening the fuel valve.
I do the same procedure as you but I only advance the mixture after it begins to fire and I only move it forward slowly.
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  #3  
Old 08-05-2017, 07:28 AM
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RONSIM RONSIM is offline
 
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Default Sounds similar to my RV-10 story, IO540

It came from the overhaul shop with retard mags, and no Slickstart -- took about 18 months of dead batteries to figure it out --- installed Slickstart and problem went away.

Ron
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  #4  
Old 08-05-2017, 07:39 AM
vic syracuse vic syracuse is offline
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I think you are overpriming. I have found it takes very little prime, less than 2 seconds of pump with the throttle only cracked about a quarter.

Try that.

Vic
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  #5  
Old 08-05-2017, 08:35 AM
Adriaan Kleyn Adriaan Kleyn is offline
 
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Vic, what do you do with the mixture after priming? Do you leave it fully rich or do you catch it when it fires.
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  #6  
Old 08-05-2017, 09:08 AM
BillL BillL is offline
 
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Read this: http://www.vansairforce.com/communit...43&postcount=9
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  #7  
Old 08-05-2017, 01:05 PM
rvbuilder2002 rvbuilder2002 is offline
 
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With the first (RV-14A) prototype, we learned after some initial struggles, that the Andair fuel pump is a very high volume flow pump.

Any RV model equipped with the Andair pump will require a change in priming technique from what people have always used / learned.

First start of the day in warmer weather I put throttle and mixture full fwd and run the pump for about 1 second (in mid summer temps even that is sometimes too long). Then set the throttle to about 1/4" open and crank. It should start right up.
In (our pacific north west) cold weather I double the time. In real cold climates you might have to do 3 seconds, but I doubt it will ever require more than that.

For hot starts I use the mixture sweep method with the throttle open about 1/2"

Side tip...... If you do get a start but the engine is stumbling badly Usually because it is heavily rich / over primed, immediately pull the mixture to cut-off. When the engine operation begins to smooth out, push the mixture back in to about the 2/3rds fwd point and adjust the throttle for proper idle.
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  #8  
Old 08-05-2017, 02:52 PM
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woodmanrog woodmanrog is offline
 
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Default I know your pain

We had the same issues. Here is how we do it.(Lycoming instructions) Cold start: all controls fully forward. Pump on 3 seconds. Mixture at idle cutoff, fully aft. Throttle open 1/2 inch. Advance mixture slowly while turning over engine. Fully advance mixture when engine fires and adjust idle. Hot start- Throttle FULLY forward. Mixture forward, prime 2 seconds. Mixture fully aft to idle/cutoff. LEAVE THROTTLE AT FULLY FORWARD. Turn engine over and DO NOT push in mixture until engine fires. Push mixture forward and QUICKLY retard THROTTLE. Resist temptation to advance the mixture knob until engine fires! Also, just turn engine over only 5-7 seconds at a time. Let system rest about 30 seconds between tries. Our personal final solution is to install Pmags.
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  #9  
Old 08-06-2017, 07:05 AM
vic syracuse vic syracuse is offline
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Quote:
Originally Posted by Adriaan Kleyn View Post
Vic, what do you do with the mixture after priming? Do you leave it fully rich or do you catch it when it fires.
The mixture is in idle cutoff for starting and I move it forward as it catches. Seems to work well so far.

As Scott, mentioned, the pump seems to flow much more fuel than we have been used to. I'm amazed at how little priming is needed.

Vic
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  #10  
Old 08-06-2017, 07:51 AM
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DanH DanH is online now
 
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A cranking engine will fire only when the in-cylinder fuel-air ratio is within a narrow range. It's near impossible to figure out a perfect "sweet spot" setting for all conditions and all airplanes.

So, a successful start procedure finds the sweet spot by sweeping fuel-air ratio through a range of mixtures while cranking, moving either from rich to lean, or from lean to rich. At some point in the sweep, one or more cylinders pass through the sweet spot, and it fires.

Think about how to sweep the mixture, experiment with the knobs a bit to accomplish a sweep, and you'll arrive at procedure that works for you.

http://www.vansairforce.com/communit...8&postcount=18
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