Jump to content
The simFlight Network Forums

Starting LJ45 engines in FSX issues


Recommended Posts

Im having 3 different mixed up issues with engine starting in FSX and it's driving me nuts. In FS9, via my FDS hardware/software that uses either keypresses or offsets, I have successfully interfaced the L and R engine switches to start each engine individually after pressing and releasing the momentary switch and once the engine begins to settle it the interface solution Im using also turns on the generator for that engine. However, as Ive began trying FSX Ive ran into some majory aggravations.

Example 1: You press either L or R Engine Start and that engine shows START on the EICAS and begins the spool process and eventually fires off and settles. This is the 'Normal and Correct' procedure that works fine each and every time in FS9 using offset 0892 bit 1 OR 4 (L engine or #1) and offset 092A bit 1 OR 4 (R engine or #2). Sometimes this works in FSX, However, in FSX this is not the usual case (using these offsets and bits). If it doesnt work right then I get Examples 2 and 3-

Example 2: You press either L or R Engine Start and that engine shows START on the EICAS and begins the spool process and eventually fires off and settles. This is where things get crazy in FSX. All of a sudden after the selected engine is started the OPPOSITE engine is now starting without any command/hardware being touched at all. It's as if the offset is actually sending 'Ctrl-E' for autostart. What's with this? A few seconds later both are running fine but START is displayed on one of the two engine start switches, and it's sometimes the first engine you started BUT sometimes it's the 2nd engine that was started automatically via voodoo magic. I see no pattern here which way is more prominate.

Example 3: You press either L or R Engine Start and that engine shows START on the EICAS and begins the spool process and eventually fires off and settles. The selected engine starts and then you start the next remaining engine (L or R) and for some reason the START command has illuminated again without any intervention via hardware on the originally started engine. To get rid of it you must now reveal the panel since I have a full size cockpit and turn off the Start Switch via mouse.

What is most frustrating about this is not the fact that I realize FS9 and FSX behaive differently, but in that I get different results ( 1 of the examples above) each and every time. Why is it different? From what I see in the FSX offset listing, these are the same from version to version.

I have considered deleting my default flight situation and reverting to the orginal FSX default flight situation and seeing if having that setup will 'correct' anything Ive messed up. I do know that the F1 PC-12 had a requirement for you to first load up the default C182 in order to properly start up the Pilatus.

Thanks for reading this- it's very frustrating when it works perfect in FS9 but FSX.

Eric

http://www.FlightLevel180.org

Link to comment
Share on other sites

Im having 3 different mixed up issues with engine starting in FSX and it's driving me nuts.

With the default 737-800? I think the logic in FSX is broken.

Example 1: You press either L or R Engine Start and that engine shows START on the EICAS and begins the spool process and eventually fires off and settles. This is the 'Normal and Correct' procedure that works fine each and every time in FS9 using offset 0892 bit 1 OR 4 (L engine or #1) and offset 092A bit 1 OR 4 (R engine or #2).

Er, offsets 0892 and 092A aren't bit oriented. They are values. For jets the starter value is 1. The value 4 is for props.

Example 2: You press either L or R Engine Start and that engine shows START on the EICAS and begins the spool process and eventually fires off and settles.

Surely, for a jet, it shouldn't "fire off" till you enable the fuel by moving the start lever to the idle position -- performed in FS by full mixture (16384 to offset 0890, etc). Then when the compbustion flag is seen 0894 etc) you should return the start switch to 0 or 2.

This is where things get crazy in FSX. All of a sudden after the selected engine is started the OPPOSITE engine is now starting without any command/hardware being touched at all. It's as if the offset is actually sending 'Ctrl-E' for autostart. What's with this? A few seconds later both are running fine but START is displayed on one of the two engine start switches, and it's sometimes the first engine you started BUT sometimes it's the 2nd engine that was started automatically via voodoo magic. I see no pattern here which way is more prominate.

Example 3: You press either L or R Engine Start and that engine shows START on the EICAS and begins the spool process and eventually fires off and settles. The selected engine starts and then you start the next remaining engine (L or R) and for some reason the START command has illuminated again without any intervention via hardware on the originally started engine. To get rid of it you must now reveal the panel since I have a full size cockpit and turn off the Start Switch via mouse.

Hmmm, very strange. I had something daft like this happening for a little while with pmSystems -- not the same. I got one engine started okay, then when the next was started the first cut out. I never proved for sure what was causing it, but i think it was something to do with the N1 or N2 values being too low, as I could never reproduce it with a slightly higher throttle setting. And then the symptom disappeared in any case.

To see what is happening between FSUIPC and FSX, enable some monitoring and logging. Enable logging of Events (one of the items on the left hand side of the logging Tab). And on the right-hand side set monitoring on 0890, 0892, 0928, and 092A, all as U16. This assumes you have start levers. If you have mixture full enabled all the time then maybe instead monitor 0892, 0894, 092A and 092C so that we catch the "combusting" state too. Below the list enable "normal log" (or whatever the top left selection is called, for logging). Then we'll get the SimConnect changes logged too.

Just do this logging during a start sequence. Try and get one of each of your variations so we can see what is happening.

But before any of this, can you check and list what add-on programs you might be using which could interfere, and also, of course, as always, state FSUIPC version number, FSX mod state andwhich aircraft you are talking about?

Regards

Pete

Link to comment
Share on other sites

Thanks Peter. I will get that info plus look at the logging too. Im sure Im not at the latest level of FSUIPC 4. Also thanks for the clarification on value 4 vs. 1, I would always get FS9 to start the LJ engines with 4 but it didnt work in FSX so I changed it to 1 and it's working, but again not fully the way I had hoped it would. I somehow missed what the difference was along the way.

"Surely, for a jet, it shouldn't "fire off" till you enable the fuel by moving the start lever to the idle position -- performed in FS by full mixture (16384 to offset 0890, etc). Then when the compbustion flag is seen 0894 etc) you should return the start switch to 0 or 2."

Yes, the LJ45 is started by moving the levers out of Idle Cutoff to Idle and then START for L or R engine. The rest is automatic (generators and everything). Then repeat for the remaining engine.

Again I appreciate your feedback and it helps (although aggravates) knowing that the 738 may be broken so it may be here too as well.

Link to comment
Share on other sites

  • 3 weeks later...
Again I appreciate your feedback and it helps (although aggravates) knowing that the 738 may be broken so it may be here too as well.

I have just yesterday located and fixed a bug in FSUIPC4 which may have been responsible for some of your problems. If you would like to download 4.531 and try it, I'm sure you'll find it no worse and maybe better.

Regards

Pete

Link to comment
Share on other sites

Oh, thank you very much Pete. I will be sure to give it a try. I did notice one thing that I think is the culprit if it's not on your end. It never dawned on me to consider how the bitmap start switches work in the LJ45 for FSX. Once pressed, they stay on until you press them again to turn them off. I dont know if it was intentional or not, but it seems to me that MS wanted to model the 'autostart' function a little better this time around (FSX vs. FS9) but instead of modeling a momentary that 'sticks' until the engine is started and releases, it modeled it as an alternate/latching switch. In the real aircraft the switch is momentary and you press it for a second or less, release and then the starter STARTS until then engine has lit off and then the starter automatically shuts down. This is easily modeled in FS9 using interface hardware that can send a function for a time period and then release (I use the Flight Deck Solutions SYS3 card) and it's possible because the FS9 start switch for LJ45 requires you to press and hold it in the bitmap panel, which is wrong too, but at least when you quit pressing it, it releases the virtual switch. For FSX, you must click on the start button once your engine is running to get the start button to turn off the starter, which I believe is the root problem. Then you have the 2nd issue where sometimes it randomly wants to start the 2nd engine after starting the first, all without ever touching the other engine's start switch.

Again, thanks for your help. I will try the new version and hope that it helps. As you say, it cant make it worse :-)

Link to comment
Share on other sites

This is easily modeled in FS9 using interface hardware that can send a function for a time period and then release (I use the Flight Deck Solutions SYS3 card) and it's possible because the FS9 start switch for LJ45 requires you to press and hold it in the bitmap panel, which is wrong too, but at least when you quit pressing it, it releases the virtual switch. For FSX, you must click on the start button once your engine is running to get the start button to turn off the starter, which I believe is the root problem.

Using the offset facilities, FSUIPC has always handled all this by continually pressing the starter (i.e "latching" it for you, until you change the starter switch yourself. It is documented that way -- you watch the "combustion flag" offset and when it sets, you write 0 or 2 back to the starter offset. That works in FS98 through to FSX/ESP.

This actually applies the same way to props, where the Starter position on the mag switch is spring loaded and you do have to hold it -- no solenoid catch.

Then you have the 2nd issue where sometimes it randomly wants to start the 2nd engine after starting the first, all without ever touching the other engine's start switch.

I think that may be related to the problem I've just fixed -- assuming you are using FSUIPC offsets, that is.

Regards

Pete

Link to comment
Share on other sites

  • 2 years later...

Hi Pete

I know it's been quite a long time since the last post on this thread from me on this subject, but I wanted to let folks know that you did fix the problem that I was having. Sorry I didnt come back and make it known a long time ago, but it just dawned on me to check into it a few days ago since I had gotten fed up with FSX and this was just one of the issues I was having at the time. I checked it with the latest version (shows how often I update FSUIPC) and it works perfectly now.

Thanks again,

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use. Guidelines Privacy Policy We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.