The A2A Simulations Community

OK, I know this has been discussed. I've searched and read the threads.

Just purchased the 172. I've been flying the A2A B-17 for three months with no issues.

The 172, I just cannot start it. I've tried everything. I've followed all the directions. Its very frustrating.

I've never flown a plane or been in a C-172, but I can't believe they're this hard to start in real life. They never would have become such a popular aircraft if all you have to do is look at it wrong and it won't start.

I've tried 10 different 30 minute sessions trying to start it. I've been successful twice.

Where do I go from here, I'm ready to give up?

Hi there,

Well since it seems like you’ve tried a lot is it safe to assume that your simulation is all up to date, there is no issues in the walkaround (shift+8) and or the hangar (shift+7) and there is sufficient fuel and oil in the aircraft (shift+4)? Did you check in the hangar if the engine is flooded after unsuccessful attempts to start? It’ll give you a good idea if your priming to much or to little.

If so and it still doesn’t start following the checklist may I ask what the ambient temperature is when you try to start the engine? This has caught me out a couple of times. The simulation seems to react sensitiv to high ambient temperatures with regard to flooding the engine.

Don’t give up though. Once you’ll get the hang of it it’ll become a lot easier to do!

Happy flying

Hi,

Does it start with the automatic "Ctrl+E"? The key is the priming and the temperature like Sebastian said. Read the manual portion of engine normal procedures and starting. A2A planes are very realistically modeled - study sim aircraft and need to be handled like the real thing. Let us know if you have more questions, we would be glad to help.

Cheerz,
Will

I do suspect that I'm flooding it. I didn't know that I could tell in the hanger. I do go there and check things but I haven't seen any problems mentioned.

I have started it using the Ctl-E once when I couldn't start. But I only tried it once.

I did just get it started right after I posted this thread. I did that by setting the throttle to about 70%. I'm going to try that again. I'm also going to try to prime a lot less; maybe just 1-2 seconds.

Also another question. The manual and check list say that if the engine is warm not to prime it. How do I tell if I should prime or not?

(Thanks for the responses, BTW)

OK, I got it started again with more throttle (about 50%) and once it starts kicking I push the mixture in and slightly back a couple times then it started fine.

Seems like you just need to get the hang of it.

Maybe I should have fought thru it more before posting. But thanks for the help.

Hi,

Good to hear you have progress there. C172 is fuel injected engine, which means after priming the mixture should be pulled out and throttle 1/4 inch as per the manual. I usually set the throttle between 19% to 23% after 4-5 sec of priming and mixture full out.

Cheerz,
Will

Good to hear you’re getting there. If you need that much throttle to get it started it sounds like the engine has to much fuel injected. Try priming less.

As for warm engine start i think the general rule is no priming until 30-45 minutes after the last flight. It’ll just take some practice and you’ll get there.

Happy flying

Just to close the loop on this thread. I am getting there. It seems a little fickle, but I can start it now. It just taking a little learning curve. Thanks everyone for the comments.

And they really aren't that easy to start. A lot of people at the airport struggle to get these engines started in the beginning of their journey to become pilots. Hot starts with fuel injected engines can also be a real pain due to vapor lock.

One you get the amount of prime, throttle position and control knob jockeying down it will be second nature. Remember that you need fuel, air and spark , in the correct proportion and at the correct time, for the engine to run.

These engines have fixed ignition timing and mechanical fuel injectors that maintain a constant spray if fuel into the induction system. The design is many decades old and requires the pilot to do a lot of the work that modern ignition systems manage today.

The engine starting checklist in the manual recommends 3-5 seconds of priming. In my opinion that is too much. Until I reduced the priming to 2 seconds or less, I struggled to get the engine started as well.

For reference, below is Step 7 from the engine starting checklist in the manual:

7. Mixture — SET to FULL RICH (full forward) until stable fuel flow is indicated
(usually 3 to 5 seconds), then set to IDLE CUTOFF (full aft) position.

Sounds like you're getting the hang of it, but just thought I'd add my experience.

"The engine starting checklist in the manual recommends 3-5 seconds of priming. In my opinion that is too much."

I agree. That's one of the changes I made to start on my path of being "successful". I hold it to 2 seconds. But I still have to open the throttle a little more than I would call "a crack".

But it does start.

The engine needs more primer in lower temperatures, but in 26C, yes, 5 secs is too long. I’ve never flown my C172 in really low temps, but I know the B17 requires more primer to start when it’s really cold

I can only echo that the C172 and the C182 do not need a lot of priming in high temperatures. If the temps go higher than 30C I find that 1 second of priming is plenty. I struggled with this also for a while.

In my opinion in the simulator it is sometimes a little bit difficult to be aware of the ambient temperature since you cannot feel it. So I made it a habit to check the thermometers before attempting to start

Happy flying

I cannot even get this thing to fire the slightest bit following the procedures. I've tried 1 second of priming, 3 seconds of priming, 5 seconds of priming - nothing. Not a rumble. Just keep burning out the battery and occasionally replace a starter. It starts up fine with the auto-start in the shift-3 menu. I'm getting incredibly discouraged because I'm not getting anything aside from cranking, no firing whatsoever. Fuel cock is on, I get pressure when I prime, etc. The real ones I've been in have been somewhat finicky but they at least always fire a bit - it's like the magnetos are off or something, but they can't be in this thing. No problems in the hangar, other than the occasional battery recharge or starter replacement when I let it go too long out of frustration. I've watched several videos and tried everything.

----

So, after writing the above crab/rant, I noticed that after autostarting, while taxiing the plane was bouncing like crazy, the brakes would not engage fully despite verifying no control problems, and it would get a max speed of about 45kts no matter what I did. So, I deleted all the aircraft files for the 172 to fully reset the saved state to a completely fresh aircraft and everything is fixed. I was able to start it without issue, taxiing went fine, so did takeoff and the flight. I suspect something got jacked up in that file, probably because I've had it since the 172 was first released 5 or so years ago and never reset it from old versions to P3Dv4. I know it was suggested elsewhere in various threads, but wanted to report my experience with it. It was very frustrating trying to start an engine that just wouldn't catch.

-stefan

shortspecialbus wrote:I cannot even get this thing to fire the slightest bit following the procedures. I've tried 1 second of priming, 3 seconds of priming, 5 seconds of priming - nothing. Not a rumble. Just keep burning out the battery and occasionally replace a starter. It starts up fine with the auto-start in the shift-3 menu. I'm getting incredibly discouraged because I'm not getting anything aside from cranking, no firing whatsoever. Fuel cock is on, I get pressure when I prime, etc. The real ones I've been in have been somewhat finicky but they at least always fire a bit - it's like the magnetos are off or something, but they can't be in this thing. No problems in the hangar, other than the occasional battery recharge or starter replacement when I let it go too long out of frustration. I've watched several videos and tried everything.

----

So, after writing the above crab/rant, I noticed that after autostarting, while taxiing the plane was bouncing like crazy, the brakes would not engage fully despite verifying no control problems, and it would get a max speed of about 45kts no matter what I did. So, I deleted all the aircraft files for the 172 to fully reset the saved state to a completely fresh aircraft and everything is fixed. I was able to start it without issue, taxiing went fine, so did takeoff and the flight. I suspect something got jacked up in that file, probably because I've had it since the 172 was first released 5 or so years ago and never reset it from old versions to P3Dv4. I know it was suggested elsewhere in various threads, but wanted to report my experience with it. It was very frustrating trying to start an engine that just wouldn't catch.

-stefan

Ok, this isn't solved at all. I ended my flight yesterday after landing and shut down. I started the sim back up today, same aircraft, and it was once again completely impossible to start. I did the Auto Start and it started right up, but once again it's "bouncing" again while just stationary in its parking spot. Taxiing is crazy and once again it refuses to accelerate past 40 kts and the brakes are messed up. Quitting the sim and wiping the Documents\A2A\FSX\Cessna172\C172RLog.dat file fixes it once again for one sim session, it would seem. I've uploaded the .dat file to http://pages.cs.wisc.edu/~stefan/C172RLog.dat in case you want to take a look at this. THis does not seem to happen with the Comanche as far as I can tell (my 182 and Cherokee 180 are stuck waiting on Lewis to get back to me about my FSS purchases that are in FSS Limbo). Checking for updates for the 172 shows no updates. This is P3Dv4.3.

-stefan

Edit: now it's happening with the Comanche too. What is going on here? This is getting very frustrating.

Edit 2: Something is very wrong. I'm going to contact support via e-mail because this is too much for the forum.