Can anyone walk me through a good ‘hot start’ procedure? I tend to want to flood the engine when trying to start and the engine has not cooled down. Thanks.
I’ve had two SR-22’s and found them each to be a little different. I’ve found the best solution in my current SR-22 to push the mixture full forward, prime for about 2-3 seconds, and then crank. I turn the boost pump on when I start cranking, and this method usually seems to fire right away. There was a thread on the members forum about a month ago talking about several other ways to do this. Good luck!
In reply to:
Can anyone walk me through a good ‘hot start’ procedure? I tend to want to flood the engine when trying to start and the engine has not cooled down. Thanks.
I was having this problem as well and yesterday I did a hot start 20 mins after shutting down. I opened the POH and was looking for a hot start procedure that maybe I missed. I found a line about NOT priming when the engine was hot. So I tried it and I’ll be damned, it started in about 4 seconds. Mixture rich, throttle a 1/4", boost pump on, NO priming, crank.
That worked for me that time, maybe it was a fluke but that was the best hot start I ever had…
Rick
In reply to:
Can anyone walk me through a good ‘hot start’ procedure? I tend to want to flood the engine when trying to start and the engine has not cooled down. Thanks.
These are all good techniques. The one thing I would add is that if I know it’s going to be a hot start (say a start at the fuel island after refulling) I don’t shut down with the mixture. Leave the mixture right where it was and shut the engine down with the key.
The rest of the technique is as described, boost pump on, throttle closed and crank.
Caution: you are counting on the mags being properly grounded. If the engine stopped when the key was shut off, you just proved the ground circuit is intact. However, it is still a possible hazard and this technique should not be used if the aircraft is being left unattended.
Although it is not the season for what I would call a “real hot start” there is a technique that works if it is so hot that the fuel in the line to the electric pump might vaporize.
The first technique is to leave the oil filler door open right after shutdown. This provides a chimney effect to cool the engine to reduce the possibility of vapor. The potential problem is vapor on the suction side of the electric pump, not to be confused with vapor between the electric pump and the injector pump. The problem is most likely to be seen at a very hot ramp at a high altitude airport where the aircraft is shut down for 45 min. to 60 min.
If you don’t see any indication of fuel flow when the electric pump is in the Boost position and the pitch of the electric fuel pump is higher than normal, you have vapor on the suction side of the electric pump.
To fix this, take the keys with you and get the fuel sampler. Get under the engine fuel drain and have someone else switch the Boost switch on as you draw a sample or two. As you draw that sample, relatively cooler fuel is being drawn from the tank to replace the fuel you draw from the sample valve. The fuel you draw willl probably be liquid.
When you hear the pitch of the electric pump drop you will know it is pumping liquid fuel and then you can go through the hot start procedures outlined. None of them will work if you don’t have fuel pressure from the electric pump.
If I remember correctly, I got the procedure I use from the Engine Tips book (TCM publication) that came with the airplane.
- Mixture - IDLE CUT OFF
- Throttle - FULL
- Boost Pump - ON FOR 30 SECONDS
- Throttle - 1/4 Open (to the E)
- Crank
Setting the mixture to cut off and the throttle to full has the effect of sending almost all of the fuel between the boost pump and the injector pump back to the tanks. This clears any vapor and uses cold (not vaporized anyway) fuel from the tanks to cool the fuel lines. Some fuel makes it to the cylinders, so it us usually not necessary to prime.
–Galvin
As mentioned, for some reason, each engine’s hot start procedure needs a different approach. Opening the oil filler hatch on the cowling is always a good idea. My starting procedure is:
1.Throttle and mixture full open.
2. Run boost pump, not prime, at least ten seconds.
3. Throttle full open, mixture idle cutoff.
4. Crank: usually fires in 1 or 2 seconds.
5. Immediately at first sign of firing, throttle back, mixture full rich.
Nevin
I have a continental IO470. The following works always:
-mixture full rich
-throttle cracked
-crank, a couple of blades pass by
-engine fires
-high boost then runs smoothly
-never failed yet
I fly a Lycoming AEIO540…so this may have NO relevance to your Continental, but the general rule we follow for hot starts is mixture off, throttle barely open, turn the engine until it fires (usually no more than 2 full rotations or six blades) then ease mixture in quickly, but not instantly. Sometimes I find that pumping the mixture slightly while the engine turns helps. Priming on my engine would guarantee to flood it, if hot. I also get vapor lock occassionally…I just tweak the starter a few times till the engine pushes through it.
Again…none of this may be relevant to the Continental engine, but one thing is probably true for all engines. Mixture off will avoid flooding…so it’s not a bad place to begin, if you suspect you are having flooding problems
David
As montioned, every engine is a bit different but I used the same procedure you have just outlined. First of all, after every shutdown I always vent the oil and leave the oil door open tp vent heat for several minutes.
Then, for the hot start I do the following:
- Mixture full rich
- Throttle just barely open a crack
- NO PRIME
- Boost on and crank
If the engine acts like it want to quit, retard rather than advance the throttle and leave the boost on until running smooth. Seems to work every time but when it is very hot in the summer, it takes longer cranking time to get there.
In reply to:
As mentioned, for some reason, each engine’s hot start procedure needs a different approach. Opening the oil filler hatch on the cowling is always a good idea. My starting procedure is:
1.Throttle and mixture full open.
2. Run boost pump, not prime, at least ten seconds.
3. Throttle full open, mixture idle cutoff.
4. Crank: usually fires in 1 or 2 seconds.
5. Immediately at first sign of firing, throttle back, mixture full rich.
Nevin
Exactly. I do the same thing and can’t imagin doing it any other way. Works great.
Jack Maendel Centennial SR22 C-GBCD
Jack,
Why not try it the way the POH recommends? It too works great and in the 3.5 years I’ve had my plane the hot start procedure has worked each and every time.
The method you use is actually the method recommended by Lycoming for hot starts in their fuel injected engines. I simply find the POH method much simpler and equally effective.
I will try it and see, but hey buddy it’s -42 degrees here now. Any wisdom on cold starts. Don’t give me the “Book” way. I’m looking for something that works.
All I can tell you is that while it’s not quite that cold in Chicago, the POH method for hot starts has always worked for me. Also, for a HOT start, the ambient temp really doesn’t matter. The engine is HOT. If the engine has cooled down significantly after shutdown then the normal start procedure should be used.
The Cirrus is the 5th airplane I’ve owned and mine has started without difficulty using the book procedure for the 3.5 years I’ve had it. In fact it has been the most consistently easy to start aircraft I’ve owned (the others were a M21 Mooney, a PA32, a S35 Bonanza, a BE55 Baron and a BE60 Duke)
Jerry,
I thank you for your time and input. I’m in no way knocking your (POH) method. In fact I look forward to trying it again sometime.
Jack