Starting the C172

[CptLemons]

Hi all,

I've had the A2A C172 for a little while now however, I've never been able to start it manually.

I follow the start-up checklist and do everything by the book (I have successfully manually started the A2A PA24 and PA28) but when I turn the ignition switch to start, the prop spins and the engine cranks but it doesn't fire.

I did get it started briefly this evening for a moment before it stalled almost straight away.
I usually run the battery dead everytime I try starting the thing.

I typically have to use the auto-start feature which I dont really like personally.

Any ideas please?

FSX:SE, latest update installed, Windows 10 64 bit

[Scott - A2A]

Just as a test, rather than prime before cranking, get the engine cranking, throttle cracked, mixture forward, then turn on the electric fuel pump and see what happens.

If it starts, you can be pretty sure you are either under or over priming. If you suspect you have over primed, open the throttle and crank the engine and wait. It should catch at some point.

Scott.

[CptLemons]

I'll give that a go tomorrow... Think that could be the case.

When it fired earlier, it was because I enabled the fuel cut off whilst the engine was cranking then disabled it and the engine fired briefly.

The electric pump (3-5 seconds) is essentially the primer then?

[CptLemons]

Just as a test, rather than prime before cranking, get the engine cranking, throttle cracked, mixture forward, then turn on the electric fuel pump and see what happens.

If it starts, you can be pretty sure you are either under or over priming. If you suspect you have over primed, open the throttle and crank the engine and wait. It should catch at some point.

Scott.

Tried this with no luck!

Any other thoughts?

[Nick - A2A]

Any other thoughts?

Have you confirmed there's fuel flow on the gauge when priming? (the needle will move a bit and you should be able to hear the fuel pump sound change in pitch too.)

If you have, and you're not over-priming which seems to be the most common issue, I'd suggest advancing the throttle a bit more when starting. Somewhere between 20% and 30% should do, but just barely 'cracking' it doesn't seem to be sufficient.

If that doesn't help, check the maintenance hangar for defective mags and so on.

Cheers,
Nick

[iefbr14]

Any other thoughts?

My personal favorite is the fuel valve

Andreas

[Pistonpilot]

Also, if you are using real world weather and have only been flying somewhere that is rather cold, might be worth trying with warmer temps.

-Ian C

[CptLemons]

Thanks all.. to answer some of you:

Fuel flow is confirmed by the gauge and fuel pump pitch change.

I'm trying to take off with OAT 6 Celsius.

And, I've tried replacing the spark plugs, starter, fuel pump and a few other bits from the maintenance hangar and that's not helped. Will try the fuel valve if I haven't already tried that one!

Shouldn't the aircraft be able to start in cold weather? That's part of the realism is it not? Haha

[Lewis - A2A]

Hello,

can I ask that you have made sure all relevant loading is sorted via the load manager, fuel, oil etc and also ask how you are loading the flight itself?

thanks,
Lewis

[CptLemons]

Hi Lewis,

Yup, all quantities checked and loaded via the fuel and payload manager.

Loading the flight:

From FSX free flight menu, setting real world static weather, loading on either the apron or the runway.

Plane starts cold and dark, as I do with all my A2A planes, and I start them all manually.

I've even tried emptying the fuel and refilling via the A2A fuel and payload manager.

I've got a video that I'll upload to YouTube and link here later today.

[Nick - A2A]

Shouldn't the aircraft be able to start in cold weather? That's part of the realism is it not? Haha

It should start easily at 6°C - that's not even really cold, though you'll probably need to prime for around 5 seconds. As mentioned above, make sure you've got the throttle open sufficiently and don't forgot to advance the mixture lever smartly once the engine does start.

If the fuel valve was in the shut-off position you wouldn't see any fuel flow, so I don't think that's the problem here.

Cheers,
Nick

...Edit - just seen your post about the video. Yes - that will help a lot!

[CptLemons]

SO...

Just trying again from the very beginning. Following the checklist - but checking the maintenance hangar for any advisories this time which indicated fouled plugs so replaced these - and OAT of 10 Celsius this time and it started on the first try!?

God knows what was different this time as opposed to the countless other times but whatever it was worked!

[Pistonpilot]

Glad you got it sorted! And, re: my cold-weather comment, I was just trying to help troubleshoot and rule out anything that could be a cause without being super obvious.

Happy starting!

-Ian C

[CptLemons]

Thank Ian.

Yeah, I did wonder about the temperature myself too. I can imagine it not working if it were -20 Celsius or something like that but +6-10 - that's practically average temp here in the UK lol

I really don't know what was different this time but hey, it worked haha

Here's my video of the C172 starting this time round:

https://youtu.be/5ix8uPeDgu8

[jb44mag]

i have tried the manual procedure and all suggested methods on the forum, and my C172 will not start in cold weather. I can't believe the "real plane" can be this hard to start. I am running "real time" weather and OAT is 23C. I have engine heater on, tried different length of time to prime, and every possible scheme to start, and no start, just runs the battery down.

Selecting auto start, as other pilots have reported, the engine starts right up. the engine will restart easily next start.

Again I can't believe the real plane is this hard to start.

-Jim