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Engine stall?

PostPosted: Wed Apr 23, 2008 8:25 pm
by PerrierBaroudeur
I have a few planes with engine problems (or is it normal?). The problem is that anytime the aircraft is not moving and the throttle is set to 0%, the engine turns off. Some even turn off while in flight if you idle the throttle. Both jets and props do this for me. Is there something in the .cfg that I can change to fix this?

Re: Engine stall?

PostPosted: Wed Apr 23, 2008 11:06 pm
by BFMF
A fellow Spokomptonite... :D

I'm not sure why that is happening. Do the engines cut out as soon as you idle them?

Re: Engine stall?

PostPosted: Thu Apr 24, 2008 12:33 am
by PerrierBaroudeur
Yay Spokane!

Re: Engine stall?

PostPosted: Thu Apr 24, 2008 12:36 am
by BFMF
Weird. I can't think of any reason why that's happening...

Re: Engine stall?

PostPosted: Thu Apr 24, 2008 1:54 am
by BAW0343
I have the same issue, perhaps in certain models the engine mixture is somehow linked to the throttle so as you come to idle the mix gets cut?

For me its usually the small prop planes.

Re: Engine stall?

PostPosted: Thu Apr 24, 2008 5:48 am
by reider
I beta test LCD Modules for CrystalFontz in Spokane too.....  Had a few test units sent to me in the UK.  I used to write some screens for users too until it was integrated with the LCD module program (CC2).  Though I still produce them for myself.

Reider

Re: Engine stall?

PostPosted: Thu Apr 24, 2008 11:11 am
by BillG
While it varies from plane to plane, idle speed is often not 0%. I'm more familiar with light planes, but in those if your range of RPM is something like 0 to 2500, idle speed is around 1000 and usually the lowest throttle setting you can get to is still around 500 or so.

Re: Engine stall?

PostPosted: Thu Apr 24, 2008 11:29 am
by Brett_Henderson
I had this problem, back in FS2002, with a plane I designed. I seem to remember that these variables are in play:

min_throttle_limit

propeller_moi

idle_rpm_mechanical_efficiency_scalar

idle_rpm_friction_scalar

Of course, this only applies to piston airplanes. I found that when adapting the C172 cfg file to a smaller plane, with a smaller prop, the engine would "quit" (gotta be careful when you use the word  "stall"  when talking about airplanes  ;)  ) at idle. Playing with those numbers fixed it.

Re: Engine stall?

PostPosted: Thu Apr 24, 2008 11:58 pm
by PerrierBaroudeur
I'll try messing with those numbers over the weekend, and I'll report back.

Re: Engine stall?

PostPosted: Fri Apr 25, 2008 3:33 am
by Daube
I had the same issue with the default CFS2 planes in FS9, letting them at min throttle would end in engine shut down. In FSX, this happens too with some planes, jets and props, no precise example in my mind, though. I think this is linked to some parameters in the cfg of the plane, for sure.

Re: Engine stall?

PostPosted: Sat Apr 26, 2008 3:14 am
by jesse_skyunlimited
Sounds like my motercycle on a cold day lol.
I recall flying a few planes that have this problem, and some that won't start using ctrl-e.

What you can try is placing a stock aircraft.cfg from the c172 into the folder, and rename the aircraft information to recognize your test aircraft. Then you can see if it idles. If it does then there is something in the aircraft to .cfg that needs to be changed, if it doesn't then it is an airfile problem.

Re: Engine stall?

PostPosted: Sat Apr 26, 2008 11:19 am
by PerrierBaroudeur
Thanks for the advice, I'll start working on that in a few hours.

-edit-

I'm using Dave Harbold's FS2002 8KCAB Decathlon as my test plane, since it has the engine cut-out problem. The .cfg file has the following values (I couldn't locate min_throttle_limit in the 8KCAB).

idle_rpm_mechanical_efficiency_scalar=1.000000
idle_rpm_friction_scalar=1.000000
propeller_moi=5.0

The values for these parameters in the default C172 were the same, but the C172 did have this line: min_throttle_limit=0.0. Unfortunately, after adding it to 8KCAB's .cfg, nothing changed and the engine still cut-out.

I tried replacing the Bellanca's .cfg with the C172's .cfg, but I had no luck with that. What do I need to replace besides the paint, panel, and sound parameters found under the flightsim.[#]?

In the 8KCAB, if you run the engine at maximum throttle and then idle it, the rpm drops immidiately to about 800 and then steadily sinks from there, cutting-out when it gets to 400. I think that limiting the minimum idle engine rpm to above 400 (if that's possible?) might fix the problem. Next thing I'll try is adding different values for the efficiency and friction scalars.