Half throttle for starting???

[Dargo]

Wow, I have to agree with the other guys in saying that I'd never start any engine and let it rev immediately. There is no way anyone will convince me that reving an engine without oil pressure is not hard on it. Now, I have had some tractors (and trucks) that flat wouldn't start without using the glow plugs first. That even seems to vary within a tractor line. For example, I've had some JD tractors that I had to use the glow plugs on or it flat wouldn't start. I've had others that would always start, no matter the temperature, without ever using the glow plugs. I've never used the glow plugs on my current tractor. I've also never started it with the throttle advanced any.

 

[Doc_Bob]

Yep, I'm not a fly boy, I just travel a lot. Spent the last couple months flying around

Baghdad area which is where the flare shot was taken. I think we have shared the same areas, Liberty, Washington, Falcon, Kalsu, Rustamyiah, Anaconda, and all points North. Been here 8 months and have slept in 49 different beds in five different countries. It's a hoot!!!

The only time I came to close to "dying" was flying. Doing the usual tactical flying, left to right, up and done. The guy on the controls was fine. We saw power lines ahead. Everyone except the fellow on the controls. The pilot not in command said, "do you see the wires". No response. Me? I saw the wires and they were big wires. Second challenge, "do you see the wires". No response. We are flying full out and low. The wires are coming real fast and we are headed right at them. Just before we hit the wires, the aircraft jerks up. We missed those wires by inches. Dead silence. About a minute later, the pilot on the controls said, "we would have missed the wires" We all laughed, knowing that we would not have missed the wires.

Be careful.
Bob

 

[ovrszd]

The only time I came to close to "dying" was flying. Doing the usual tactical flying, left to right, up and done. The guy on the controls was fine. We saw power lines ahead. Everyone except the fellow on the controls. The pilot not in command said, "do you see the wires". No response. Me? I saw the wires and they were big wires. Second challenge, "do you see the wires". No response. We are flying full out and low. The wires are coming real fast and we are headed right at them. Just before we hit the wires, the aircraft jerks up. We missed those wires by inches. Dead silence. About a minute later, the pilot on the controls said, "we would have missed the wires" We all laughed, knowing that we would not have missed the wires.

Be careful.
Bob

For those that might not understand Bob's story, in open country we fly lower than the big power lines, the pilot has to see them and lift over them. I know it's an optical illusion but it always looks like we miss them by 30 feet or so, it's probably more. Made the hair on the back of my neck stand up just reading his story. I've felt that way as I watch us approach a diagonal power line and hope all the while that someone sees it!!! Great story!! Always Careful!!!

 

[Doc_Bob]

For those that might not understand Bob's story, in open country we fly lower than the big power lines, the pilot has to see them and lift over them. I know it's an optical illusion but it always looks like we miss them by 30 feet or so, it's probably more. Made the hair on the back of my neck stand up just reading his story. I've felt that way as I watch us approach a diagonal power line and hope all the while that someone sees it!!! Great story!! Always Careful!!!

Thanks for elaborating. Flying tactical is a trip. Never did it in USA (against the rules) until I got to Iraq. First few times it was a "rush". Then I got used to it. Then I wanted more speed, fly lower and faster. Lower, faster. It was insane.

What is tough to understand that 100 feet above the ground a 150 Knots is very dangerous. One bit of rough air, and bam, into the ground. The helicopter pilots have nerves of steel and incredible concentration. They make it look easy. Looks are deceiving. I never shared this with my wife. She was worried enough as is.

Flying at the altitude and speed is wicked. And not just for a few minutes, but it can be for 20 minutes. Watch the houses on the ground come and go is the blink of an eye. No time for anyone to take a shot at us. And with flying tactical and always changing our routes, the bums were never able to predict where would be next trip over head.
Bob

 

[Tazz]

YOU MAY NOT BELIEVE THIS!!!

I did a quick search on the internet about throttle position when starting a diesel and found many links that say way to do it is with the throttle partially open.

I have a TC-29D and the manual states to open the throttle 1/4 to 1/3 for starting. Sooooo... I decided to live on the edge and give it a try.

Typically I have to hold the starter on to 1 - 2 full seconds before it fires off and runs (after the 6 second preheat). This time it started INSTANTLY (!) probably on the first compression stroke! And NO the engines didn't race up to high rpm's. I did bring the throttle back to full idle position immeadiatly after starting but still it never exceeded 1000 rpm's. Initial rpm rise was slow and would most likely continue up the arc but it was easy to catch it and keep it slow.

Now I think back about how much addition stress there is on the battery and starter is caused by keeping the throttle at idle and I will, from now on, open the throttle about 25% when starting.

Give it a try once. If it works better for you (or not) let us know.

TAZZ

 

[Crisswell]

I have a related question about glow plugs.

On my TC 48, the glow plug doesn't begin to energize unless I'm holding the key halfway between first stop and engaging the starter. I have to hold it there until the light goes out, then continue to the full start position. Then each time I restart it after it's the engine's warm it does the same thing.

In my Duramax equipped pick-up, the first stop on the ignition turn energizes the glow plug. When it goes out, you start it. No having to hold it halfway between the first stop and full starting positions. After it's warm, the glow plug light goes out immediately at the first stop. Seems like the way it ought to be for the tractor, too.

Is there something wrong with the TC48?

Thanks.

Andy

 

[daTeacha]

My DX29 is on a timer rather than any kind of sensor. It doesn't matter if the engine is cold, warm, or hot. If you key to the glow plug indicator, it comes on for the same length of time. It sure would be nice if the things were temperature related.

 

[Doc_Bob]

YOU MAY NOT BELIEVE THIS!!!

I did a quick search on the internet about throttle position when starting a diesel and found many links that say way to do it is with the throttle partially open.

Any reason why they suggest part throttle?
Bob

 

[Tazz]

No reason given on the other links. Many of them were starting diesels engines in boats and few were tractors / heavy equipment.

My guess is they all might have mechanical fuel injection systems and this just makes them start easier and faster.

As for the other question, (glow plugs), I looked at the wiring diagram on the TC29 and found the glow plug LIGHT is on a 5 second timer and is there just for a suggested preheat time. The actual glow plugs are being electrically heated during the entire time the switch is held in the "HEAT" or "START" position. Again I'm guessing that to go to a tempurature controlled system would be nice but would just add to the production cost.

Tazz

 

[HGM]

Any reason why they suggest part throttle?
Bob

Reading this thread, I'm coming to a couple conclusions, myself.. And, I guess I have been starting my tractor this way though never really though about it.. I have a Yanmar, there is no idle hard-stop. To shut it down, you turn the key off and completely close the throttle shutting the fuel off.. To start it, I have to open the throttle, depending on ambient temp, it will start much quicker with more throttle, so my possition will vary..

So, heres my theory........

Since a diesel has no throttle plate, you can only control the fuel.. On a gas burner, many are more familiar with them, when you started a carburated engine you would pat the throttle to set the choke, right? This would dump more fuel and air into the intake to get it fired off.. On a diesel, again since we have no throttle, we can only add more fuel to richen it up.. When it starts, due to the nature of diesel combustion(slow burn) we can start it with a high throttle setting(lots of fuel) just to get it fired off, then before the RPM goes through the roof, we can bring it down to where were comfortable(high idle speed)... I really dont see how this would cause any damage since its a gradual RPM increase, not like starting at 2000RPM..

Just my take on it after reading this and thinknig about how mine starts..