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Cold Starts

CharlieWaffles

Well Known Member
I know it is usually the hot starts on most RV10s that present challenges, but after a year I have gotten those down pretty dang well. So well, that my cold starts look pathetic next to them.

I haven't found the right mojo yet to get my stock IO-540 (ordered from vans) to kick during the first cranking. I have stock Retard Mags, Slick Start and the stock Vans installed FI - Believe its a Eagle Hawk? I also upgraded to the larger Skytec 142NL starter

All my cold starts involve priming and I have tried using fuel flow as the guide (3-4GPH) before starting, tried fuel pressure, and even just counting. All result in the same thing. Crank for up to 15 seconds. Pause to let starter cool, and then do the same exact thing again and the second time around it kicks by the first or second blade like I expect it to initially.

So I am wondering what COLD start recipes people use for themselves? Perhaps there is a combination I haven't tried yet.
 
My cold start method for my IO-540 4VA5:
Throttle cracked 1/4", mixture full rich. Turn on boost pump and after the pump primes and builds pressure (you can hear the change in pump noise), count to 4 or 5 and turn off pump. Don't over prime or it floods. Mine fires by the 2nd blade. I have impulse coupled Slick mag on the left (6351) and non-impulse Slick on the right (6350). No Slick Start.
 
All the IO360 and 540's will start cold with the following.

1. Throttle WOT and Mixture rich, boost pump on count 1-2-3, pump off.
2. Close throttle and mixture to ICO, crack throttle to a position on your controls that would typically give you 1200 RPM.
3. Crank, as soon as it coughs roll the mixture in, I never see a need to go past half way. Then lean back to RPM rise and slight fall.

For a hot start, do not use boost pump at point 1, although if really hot it may be required after start due to heat soak of the pump.

Next thing to seriously check. Plugs! Gapped right at 0.016-0.018" (or use fine wires) and resistance under 5000 ohms.

:)
 
what I have have done for many years and on many airplanes ,boost pump on full throtle mixture rich count to six, boost pump off retard throttle, miture lean ,crack throttle start ,roll mix In.
same as above post except 3 more seconds ,always starts in one or two blades assuming good ignition
 
How I do it.

Full throttle, full rich. Boost 3-4 seconds after the pressure comes up.

Throttle retarded to 1200---1500 RPM apx, leave mixture full.

Crank---------almost immediate start then ease off throttle to high idle and lean as needed for idle position.
 
I'm having the same cold start issues as Mark on my IO-320. I always end up spinning the engine with the starter at least 2 or 3 times before the engine even offers up a cough or sputter. Priming times have all been varied at times. Priming amounts (throttle position during prime) have all been varied. Maybe I'm not priming enough? I will give it some more priming with the boost pump after the first failed attempt at starting, but I don't want to flood it. I use the Airflow Performance purge valve as directed by their manual to do the priming, instead of moving the mixture (always set full rich). They recommend pushing in the purge valve to RUN for 3-5 seconds with the boost pump on to prime a cold engine. The gauges show good fuel pressure and flow during priming. I've got dual P-mags, so spark shouldn't be an issue. It runs great once it kicks on!
 
IO 540 C4B5. With the same slicks(LH Impulse) as in3 , with a slick start. Tempest plugs. Same as post #3 but I only use a 3 count. That is if it has sat for over 2 days. If I am lucky it just explodes to life instantly. If not quite right it may take 4 or 5 blades.

If I fly one afternoon and start it the next morning I just crank with full rich mixture and bit of throttle open and it fires almost instantly.

Although it is seldom seen any more with glass panels, a standard fuel spider has a port that used to run a pressure line to a flow indicator, often found in the MP instrument.
This was a direct indication of fuel pressure and flow at the spider. It took much of the need to count out of the picture.


Best of luck
 
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Cold Start

I have the same setup as you - Vans stock with Slick Start, and my cold starts are very easy. It usually fires on the second or third blade. As you can see from the responses there are a variety of techniques. I crack the throttle, prop full, mixture full and prime for 5 seconds. Mixture off and start, bringing mixture in after it fires.

It seems odd that yours starts so hard. I suspect that you don't have the Slick Start wired properly. Both mags are retard breaker and the manual is not very user friendly. You have to get the jumpers correct on the start switch, too. You can screw these up a bit and the engine will still start, but maybe without the benefit of the Slick Start.

Ask me how I know.
 
Cold starts

Bruce,
I'm equipped just like you and my IO320 starts on the first blade only with a 15 count initial boost pump prime and then the 3 to 5 count with the purge valve moved to the run position and then back to ICO. Never once any hint of flooding because the purge valve in the ICO position prevents fuel being primed to the throttle body during the 15 count. Give it a try.

Kelly Landrum
IO320 RV6 AFP Lasar
Halifax, Va
 
Ten Seconds

I follow the same procedure as 9GT except I give the boost pump 10 seconds and it starts on the second blade.
 
This thread is my smile for the morning. Apparently some prime with throttle closed, and others with the throttle open. Some start with mixture at ICO, others with mixture rich. All seem to work.
 
Bruce,
I'm equipped just like you and my IO320 starts on the first blade only with a 15 count initial boost pump prime and then the 3 to 5 count with the purge valve moved to the run position and then back to ICO. Never once any hint of flooding because the purge valve in the ICO position prevents fuel being primed to the throttle body during the 15 count. Give it a try.

Kelly Landrum
IO320 RV6 AFP Lasar
Halifax, Va

That is what I have been doing (unsuccessfully) and it always takes several tries before the engine will fire up. I've tried more prime, and less prime with the purge valve. Throttle WO, 1/2 and cracked. No difference. It always takes several tries to get her started. :mad:
 
FWIW, I have a similar setup (Vans engine, slick start, retard mag, light wt start) and more often than not, it takes a second crank. But the 2nd crank is 100% reliable.

What I don't do is go to WOT during the prime, and it seems many do.

My procedure is:
- throttle cracked ~1200 rpms and mixture closed
- boost on
- Mixture full rich until flow rises and stabilizes
- Close Mixture (pump stays on) and Crank
- Move mixture to half way when if fires
Doing that, I usually require a 2nd crank

I'm going to prime with WOT and see what happens.

Thanks.
 
I see some posts talking about 10 seconds of priming :eek:

Do you really need to do that? There is a lot of fuel going somewhere, and the diaphragm in the FCU will probably be weighed down with a lot of gooney dye. Not to mention where else.

Also there are a few with a full rich position. If you are a bit over primed and leave it full rich it it gets more fuel. Better bet is ICO and roll it up when the engine coughs into life.

Does all it should and nothing it shouldn't :)
 
For a while most of my starts used to take two attempts, and sometimes 3 for hot starts. Retard breaker + Slick Start. Have the G3i now.

After some research on here I printed out David Brown's method, took it with me to the airport and it worked perfectly, every time.

Owe you a beer for that one mate!

Lenny
 
If you were in Margate Qld I would pop over this afternoon for said beer. Florida has so many place names the same as down here. Brisbane, Melbourne, Margate???

As for start procedures I am really serious about doing it right, and the "Does everything it should and nothing it shouldn't". If anything passes that test it is fine, but many methods do not.

Thanks for the virtual beer. But beware I like Florida :)
 
I never prime or boost pump In my case the fuel is already there.

Also the speed at which my motor starts is proportional to my preheat temp. Starts immediately
 
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