Starting without a primer

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poadeleted20

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I'm teaching in a Socata TB-9 Tampico this week. It has a Lyc O-320-D2A engine, with no primer system! The manual calls for "injecting" fuel by pumping the throttle, but all that seems to do is flood the engine, which flat refused to start for two very cold days (not even a cough). Fortunately, it warmed up today, but what happens if it chills out again? Anybody got any experience with this setup?

PS: Not looking for a preheating discussion, just starting this engine when cold.
 
no fuel pump? i assume you pumped the throttle while cranking the engine? beats me...
 
Throttle priming can easily lead to flooding. I find that a good technique is after you have pumped the throttle move the mixture to full lean will you start. Once the engine starts to catch, quickly move the mixture to the full rich position.
 
Try pumping while starting and not until. Start cranking then pump.

Dan
 
stingray said:
Try pumping while starting and not until. Start cranking then pump.

Dan
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That's what I'd do. Cranking while "pumping" should allow you to go from too lean to rich enough without getting too rich. There may be times when the engine and air are cold that you just can't start because the fuel won't vaporize and just collects in puddles inside the manifold.
 
That's the hot start technique I use on the IO-540 (boost pump, not throttle, tho). Sometimes I have to use it when it won't start cold, too.

smigaldi said:
Throttle priming can easily lead to flooding. I find that a good technique is after you have pumped the throttle move the mixture to full lean will you start. Once the engine starts to catch, quickly move the mixture to the full rich position.
Click to expand...
 
I am not familiar with the Socata, but in the Arrow we prime by moving the mixture to full rich while turning on the electrical fuel pump and leaving it on for 1-4 seconds. Then turn it back off and move the mixture back to full lean before starting. (Since you start the Arrow with the mixture control). My instrument instructor always did this in the Archer too and it was not fuel injected.
 
as is the case with all things mechanical, electrical, or computer.....
just caress the thing till it gets going.
 
Comet said:
I am not familiar with the Socata, but in the Arrow we prime by moving the mixture to full rich while turning on the electrical fuel pump and leaving it on for 1-4 seconds. Then turn it back off and move the mixture back to full lean before starting. (Since you start the Arrow with the mixture control). My instrument instructor always did this in the Archer too and it was not fuel injected.
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Everything I know about the Archer (+/- 300 hours) says this procedure will not start the Archer. There is something else going on here. Was the engine shut off with the mixture or the key? Did he use the primer pump?

-Skip
 
A toughy, ain't it?

Have you tried a quick spray of HotShot (ether starting spray) on a cold morning?
 
I trained for my PPL in TB9s. Procedure was to put the fuel pump on, pump it 6-10 times. Worked every time for me. If it's not working for you I'd wonder if the carb/engine is set up correctly.
 
smigaldi said:
I find that a good technique is after you have pumped the throttle move the mixture to full lean will you start. Once the engine starts to catch, quickly move the mixture to the full rich position.
Click to expand...

The flight school I did my IR at used this method for the injected 172R's as well after priming with the electric pump.
 
NORMAL START
WHILE ENGAGING THE STARTER, OPERATE
THE THROTTLE 3 TIMES AND POSITION IT
TO ¼ OPEN UNTIL ENGINE STARTS
(ENGAGE STARTER 30 SECONDS MAX)

COLD WEATHER START
SAME PROCEDURE AS NORMAL START,
BUT OPERATE THE THROTTLE 10 TO 15
TIMES WHILE ENGAGING THE STARTER IF
THE ENGINE IS COLD.


You're kidding! 10 to 15 pumps of the throttle while cranking? Man, my arm would fall off!

Found at http://avsci.slu.edu/resources/docs/parks/TB9CheckListRev5.pdf but I'm sure you already have that and this tells you nothing new.
 
Skip Miller said:
Everything I know about the Archer (+/- 300 hours) says this procedure will not start the Archer. There is something else going on here. Was the engine shut off with the mixture or the key? Did he use the primer pump?

-Skip
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We did not always have to use the primer to start up. The engine was shut down by mixture full lean. It didn't always work, but it semed to help some. I have tried it on Warriors since then and I did not have to use the primer. I try to avoid pumping the throttle a lot because it can lead to a backfire and engine fire. I only use it as last resort. Obviously a cold start in Phoenix is not the same as a cold start in NYC either.
 
Tried the starting method recommended by Tom D and Henning today -- started right up. The key to avoiding flooding is to remember that pumping the throttle before cranking merely pumps fuel into the bottom of the airbox, not into the cylinders.

Thanks to all who responded.
 
Ron Levy said:
Tried the starting method recommended by Tom D and Henning today -- started right up. The key to avoiding flooding is to remember that pumping the throttle before cranking merely pumps fuel into the bottom of the airbox, not into the cylinders.

Thanks to all who responded.
Click to expand...

Given that Tom D's method was "preheat" and as near as I can tell Henning didn't comment on this thread or else he deleted his post, what method did you end up using successfully?
 
lancefisher said:
Given that Tom D's method was "preheat" and as near as I can tell Henning didn't comment on this thread or else he deleted his post, what method did you end up using successfully?
Click to expand...
As they posted elsewhere...no prime before cranking, one or two full strokes of throttle while cranking, and then leave it at 1/3 throttle. Worked like a champ.
 
Comet said:
We did not always have to use the primer to start up. The engine was shut down by mixture full lean. It didn't always work, but it semed to help some. I have tried it on Warriors since then and I did not have to use the primer. I try to avoid pumping the throttle a lot because it can lead to a backfire and engine fire. I only use it as last resort.
Click to expand...
Here is where I am coming from: You said you used this procedure on the carbureted Archer:
in the Arrow we prime by moving the mixture to full rich while turning on the electrical fuel pump and leaving it on for 1-4 seconds.
Click to expand...
All that you have done is ensure that the float bowl is full of fuel. This does not put fuel into the intake manifold where it can vaporize in the Archer.
Then turn it back off and move the mixture back to full lean before starting.
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With the mixture at full lean (idle cut off) no fuel can get to the intake manifold. This is how you STOP the engine. So I am not seeing anything in your procedure that gets fuel into the intake manifold (carbureted engine), therefore I can't see how this procedure works in an Archer. Unless, of course, the primer is used as an alternate fuel source. I must be missing something! I look forward to the education....
Obviously a cold start in Phoenix is not the same as a cold start in NYC either.
Click to expand...
You got that right! Last time out to the airport it was about 15*F when I started the pre-heat. Wind was fortunately moderate. With the baro setting at 30.68, we had ourselves some low density altitude (3200 feet below msl at the field) and that little Archer climbed like you may never see in Phoenix!

-Skip
 
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The procedure I'm describing is for the Arrow which is fuel injected. All I said was that my instrument instructor used it for the Archer sometimes too and it seemed to help start it up faster and without having to use the primer. I've tried a couple of times on a Warrior and it did start up easily. That's not to say, of course, that it wouldn't have started had I not used the procedure. It just seems to help starting it faster and eliminates having to pump the throttle as much. As you may know, the above procedure is how to prime an Arrow as it does not have a primer pump.
 
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Comet, you are right that this is a correct procedure for Lyc fuel injected engines, so I do not doubt for a minute that it works in the IO-360 in the arrow.

Here is another description of the procedure you described for the carbureted Archer:

(remembering that the engine was shut down by pulling the mixture - thereby emptying the induction manifold of fuel/air mixture)

1) Fill carburetor bowl by using fuel pump.
2) Position mixture controls to prevent any fuel from getting into the intake manifold.
3) Crank engine.

If it works for you, keep doing it.

-Skip
 
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