Engine cut out on negative G.. and smoke issue

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MarcE
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Re: Engine cut out on negative G.. and smoke issue

Post by MarcE »

lonewulf47 wrote:
MarcE wrote:Oskar,

being parked I applied some power to maintain 1000rpm and had a fuel flow of 7 gph according to the shift 2 menu. I then pulled the mixture back slowly and the FF decreased just normal to the point where it cut. I immediatley increased mixture slowly back to full rich and the engine ran smooth at 1000rpm. the fuel flow went back to 7gph.

I then cut the power very quickly, the engine cut and is also able to restart itself, but the fuelflow doesn't decrease anymore when i lean slowly but cuts at a point. When I apply throttle, FF increases too. Running at 1500rpm and reducing mixture doesn't affect FF either but cuts it at a point.

Fuel pressure is ALWAYS jumping around 4 without any exception.
Now, if you go flying with the Mixture issue according to my theory it should quit at negative g-load and NOT be restartable.

exactly

(hab oben noch deutsch editiert)

opon41
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Re: Engine cut out on negative G.. and smoke issue

Post by opon41 »

Hey guys,

not sure if this will help but i'm going to place it here as it seems related. (as a note I run FSX:SE with ASN and FS economy running in the background)
I had just got the engine started and warmed up, all indications were normal fuel pressure was 6-7 oil pressure 72. When i hit the ~ button to switch the radios to AWOS I had a 2-4 second pause in the simulator then the engine promptly died. All attempts to restart failed, including using the GPU, the manual fuel pump, and primer. I noticed when the starter was cranking fuel pressure was about 5-7 but the engine would not light no matter what, as others restarting the sim fixes the issue. I stated that i'm running ASN which I believe also uses simconnect. Perhaps, its is an issue of too many or varying calls to simconnect at the same time? Anyways, maybe this can help you sort it out.

Matt
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MarcE
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Re: Engine cut out on negative G.. and smoke issue

Post by MarcE »

opon41 wrote:Hey guys,

not sure if this will help but i'm going to place it here as it seems related. (as a note I run FSX:SE with ASN and FS economy running in the background)
I had just got the engine started and warmed up, all indications were normal fuel pressure was 6-7 oil pressure 72. When i hit the ~ button to switch the radios to AWOS I had a 2-4 second pause in the simulator then the engine promptly died. All attempts to restart failed, including using the GPU, the manual fuel pump, and primer. I noticed when the starter was cranking fuel pressure was about 5-7 but the engine would not light no matter what, as others restarting the sim fixes the issue. I stated that i'm running ASN which I believe also uses simconnect. Perhaps, its is an issue of too many or varying calls to simconnect at the same time? Anyways, maybe this can help you sort it out.

Matt
I had ASN running too but closed any 3rd party addons to reduce the possibilities. It doesn't matter if there is sth running or not. but the 2-4s-break you mentioned MIGHT have sth to do with it as simconnect maybe gets no fuel in this time... so to say.

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Scott - A2A
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Re: Engine cut out on negative G.. and smoke issue

Post by Scott - A2A »

Marc,

Two things:
What exactly do you mean when you say "I cut power?" Did you just pull the throttle back, and this caused the issue after?
Also, would you be willing to speak directly, since I cannot reproduce anything like this on my system?

Just PM me your contact info and I can call.

Scott.
A2A Simulations Inc.

MarcE
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Re: Engine cut out on negative G.. and smoke issue

Post by MarcE »

Scott - A2A wrote:Marc,

Two things:
What exactly do you mean when you say "I cut power?" Did you just pull the throttle back, and this caused the issue after?
Also, would you be willing to speak directly, since I cannot reproduce anything like this on my system?

Just PM me your contact info and I can call.

Scott.

oups,

I cut the mixture, not the power, sry.

I'll send you a PM

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lonewulf47
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Re: Engine cut out on negative G.. and smoke issue

Post by lonewulf47 »

MarcE wrote:
lonewulf47 wrote:Now, if you go flying with the Mixture issue according to my theory it should quit at negative g-load and NOT be restartable.
exactly
(hab oben noch deutsch editiert)
That at least supports my theory. Now I think we need to find a way to reproduce this Mixture issue.
Oskar

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MarcE
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Re: Engine cut out on negative G.. and smoke issue

Post by MarcE »

ok

when I reduce the mixture slowly everything seems to work as intended.

when I cut the mixture very fast and increase it immediately very fast too, the engine caughs and keeps running but the mixture lever is without a function except the cut off point. when I take off and then push a neg g (or cut the mixture with the lever) the engine dies and won't restart again.

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Medtner
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Re: Engine cut out on negative G.. and smoke issue

Post by Medtner »

MarcE wrote:ok

when I reduce the mixture slowly everything seems to work as intended.

when I cut the mixture very fast and increase it immediately very fast too, the engine caughs and keeps running but the mixture lever is without a function except the cut off point. when I take off and then push a neg g (or cut the mixture with the lever) the engine dies and won't restart again.
Can this effect be reproduced by doing the item in the ground test-checklist - having the engine at 700 rpm or so and turning the ignition (magneto switch) off momentarily? This will turn off the engine, and might produce a similar result? It sounds like the cutting off of the engine results in some bug in the system rearing its ugly head, and the test with the ignition might be a confirmation...
Erik Haugan Aasland,

Arendal, Norway
(Homebase: Kristiansand Lufthavn, Kjevik (ENCN)

All the Accusim-planes are in my hangar, but they aren't sitting long enough for their engines to cool much before next flight!

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Re: Engine cut out on negative G.. and smoke issue

Post by MatzeH84 »

Ok, I just checked with a freshly loaded sim, started her up, let her warm and then set the RPM to 2000. No cut in mixture or mags before this. There is no change in GPH until the engine starves when I reduce the mixture.
Automixture is off, of course.

Edit.. I don't know if this could be related.. but I don't get any backfiring, pops, bangs, whatever, no matter how I jerk the throttle.
Kind regards, Matthias

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Re: Engine cut out on negative G.. and smoke issue

Post by wothan »

MatzeH84 wrote:Ok, I just checked with a freshly loaded sim, started her up, let her warm and then set the RPM to 2000. No cut in mixture or mags before this. There is no change in GPH until the engine starves when I reduce the mixture.
Automixture is off, of course.

Edit.. I don't know if this could be related.. but I don't get any backfiring, pops, bangs, whatever, no matter how I jerk the throttle.
I can confirm this.

In P3D V3.2 I make a normal start, rev the engine up to 2000 RPM (30" MP).
Moving the mixture back from full rich does not do anything to the fuelflow read on the Sh+2 menu and the engine is not starting to run rough, only when reaching the cut-off point does fuelflow drop off and the engine quits.

So fuelflow at that setting is 37.2 gph until the mixture lever reaches the cut-off point where it drops to 0.0 gph.

Auto mixture is disabled in P3D for sure, as well as engine stress and damage.

Obviously the mixture lever is not doing what´s supposed to do and maybe the issue can be tracked down to something related to that.

Note that I use FSUIPC for axis assignment where I use "Send to FS as Normal axis" and then "Axis Mixture set".
This has worked fine on all other Accusim aircraft (P-47, P-40, P-51D, Spitfire, B-17, Boeing 377, C-172, C-182, Cherokee 180, Comanche 250).


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MatzeH84
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Re: Engine cut out on negative G.. and smoke issue

Post by MatzeH84 »

FSX SP2 here.
I use FSUIPC axis calibration, so I guess this is not the point.

Quite interesting, just did an aileron roll and got the engine stuck 'half-starved'. So it accepted a small amount of throttle while sputtering, but this condition was persistent thereafter. As if negative G (or inverted flying, which would be the same) count up a percentage of engine starvation, which isn't reset afterwards. And this time I only got to 50% ;)
Kind regards, Matthias

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Scott - A2A
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Re: Engine cut out on negative G.. and smoke issue

Post by Scott - A2A »

So far it appears that this issue is only happening with FSUIPC users. We're working on putting some filters to ignore any possible corrupt values coming out of FSUIPC.

Scott.
A2A Simulations Inc.

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Medtner
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Re: Engine cut out on negative G.. and smoke issue

Post by Medtner »

Scott - A2A wrote:So far it appears that this issue is only happening with FSUIPC users. We're working on putting some filters to ignore any possible corrupt values coming out of FSUIPC.

Scott.
Interesting! I use FSUIPC, so I hope you find the filtration-solution soon, and let me know if you need some testing of it. :)
Erik Haugan Aasland,

Arendal, Norway
(Homebase: Kristiansand Lufthavn, Kjevik (ENCN)

All the Accusim-planes are in my hangar, but they aren't sitting long enough for their engines to cool much before next flight!

joers182
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Re: Engine cut out on negative G.. and smoke issue

Post by joers182 »

I'm also using FSUIPC. Great work on finding a possible solution!.
Joe W
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Moach
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Re: Engine cut out on negative G.. and smoke issue

Post by Moach »

FSUIPC here too

so far it does seem to all of us who have the problem also have FSUIPC


perhaps in this case, correlation may indeed imply causation...

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