Hi There,

i have a problem that is struggling me, and i've checked almost everything on the net before begging you.

PMDG 737 fully patched (800) Engile start issue. P3D 4.2 (same issue with 4.0 and 4.1)

Situation:

APU RUNNING

FUEL PUMPS ALL ON

L&R PACKS OFF

ISOLATION VALVE OPEN (but tried also with AUTO)

ENG 1&2 BLEED OFF

APU BLEED ON (at 10 psu)

Issue:

Starting LEFT engine (starting RIGHT same result) -> Selector to GRD

APU pressure goes to 40 PSU

N2 start rising, Fuel flow start rising Oil pressure start rising

AT 25% N2 (tried also at 20%, same result) i'm opening fuel valve

N2 continues running up, N1 start rising, EGT start rising, FF initially goes to 0.6 then lowering to 0,3

OIL TEMPERATURE WON'T RISE -> N1 STOP RISING at 20% Everything seems NORMAL except OIL TEMPERATURE that stays at external temperature and ENGINE that won't spool up when applying thrust power. It seems running normally but... not running at all...

I started also a normal default aircraft before starting PMDG. Same result

Fix

I'm removing fuel from badly started engine and then reapply GRD, engine spool up again and at 25 N2 (tried at 20 too) i provide fuel. Same result... Same result occurs if i start running the other engine... at 2nd or 3rd attempt temperature start rising normally (oil temperature) and engine goes UP with N1 to normal levels.

PMDG is fully patched... i didn't found anything on internet for that issue that is struggling me...

Any suggestion?

 

 

well, to avoid confusion, the FIX paragraph is "how i'm actually getting rid of the issue"... i don't have a fix yet...

Welcome to the PMDG forums, please note they ask that we sign our full names on all posts.

Your problem is easy to spot, you are not using the normal procedures checklist and probably have not flown both Tutorials.  The N1 stops rising at 20% because you are not providing bleed air from APU to engines for the start.  Open the ENG bleed valves (and leave them open except in non normal cases). Also, one can almost always start with one pack on.  The isolation valve position is irrelevant with both packs off.

Do not switch the fuel cutoff switch from stop to run until N1 is about 22-25%.  Hope this helps.

Well, i've read a lot about that, including B737 manuals... in that case i will run into a DUAL BLEED issue, with possible damages due to APU bleed air being counteracted by engine bleed...

I'm missing something?

1 hour ago, downscc said:

Welcome to the PMDG forums, please note they ask that we sign our full names on all posts.

Your problem is easy to spot, you are not using the normal procedures checklist and probably have not flown both Tutorials.  The N1 stops rising at 20% because you are not providing bleed air from APU to engines for the start.  Open the ENG bleed valves (and leave them open except in non normal cases). Also, one can almost always start with one pack on.  The isolation valve position is irrelevant with both packs off.

Do not switch the fuel cutoff switch from stop to run until N1 is about 22-25%.  Hope this helps.

Dan, on the 737NG the engine bleed valve position doesn’t affect starting but the isolation valve switch is important. It won’t necessarily be open with packs off so it’s best to have it in open. Also from the OP’s observations APU air pressure must be getting through as N2 is rising. 

It sounds like the OP’s set up is correct. I’ve no idea what the problem is but I don’t think it’s operator error. I’d suggest opening a support ticket. 

I've tried also with fresh restart using dual bleed technique. Same result.

Here some screen with bleed from APU only, explaining the issue:

Just after putting engine 2 into GRD mode. Notice TAT = OIL TEMP of engine 2

Engine is running at nominal values but N1 won't increase over 19.7, OIL temperature is 9 degrees, oil pressure risen to 31 and N2 is nominal

Increasing ENG 2 won't increase engine rate, N1 stays at 20,3. Fuel flow is normal, oil temperature is still 9. CONFIG on CTR fuel is not an issue in that case

Edited March 10, 20188 yr by Shezan74

I'm not sure about sim stuff (odd, I know) but don't you have the cheater to show you where the commanded N1 is? Also, I would have all bleeds on and the ISO VALVE in AUTO or CLOSED, not OPEN.

I once had a similar problem in the NGX, engine appeared to start, but would not spool up, no thrust etc. In my case, it only affected one engine, and appeared to have been caused by a corrupt saved panel state. The solution was to reset the sim to use one of the three default PMDG panel states. 

I’m not sure if this is the cause of your problem, but the symptoms are similar.

I definitely think it's a bug on my pc. I unregistered, manually removed traces of pmdg in my folders then reinstalled and tried with default cold and dark. No way. I've opened a support ticket to pmdg. 

I will let you know about answers, if any.

@Spin737 I have tried everything, all combo. The only thing I've not tried yet is to replace JP4 with prosecco 😁

Small update: i noticed that when engines are not running i hear the first stage, but i cannot hear the engine noise.

Fully removed P3D and reinstalled everything, i tried also an engine start with external bleed pressure from cart...

No way... at first attempt the engines won't start (and vibrations stays at zero)

Let's see what happens on PMDG support side

On 3/11/2018 at 4:34 AM, Shezan74 said:

I unregistered

If you're going to uninstall/reinstall, please do not unregister as part of the steps. This is wholly unnecessary, and if you do it enough, it will end up locking your license out because it looks suspicious to the server. We can manually override it, but it'll take extra time for you to submit a ticket and wait for us to get to it. Simple solution though: there's no real benefit to unregistering outside of the cases listed in the Intro: changing hardware, changing comps, reinstalling your entire OS - outside of that? Don't.

Do you use FSUIPC to calibrate your throttles/hardware?

Ok, thanks for the tip. I unregistered to make sure the process was flawlessy (i also manually deleted all PMDG related folders). Next time i will keep the old registration key alive!
Yes, i'm using FSUIPC for calibration. You colleague @PMDG HD asked me to remove FSUIPC ini file and retry that way as soon as i get back home.

I'll answer here and on ticket itself.

I will make a copy of the INI file before removing it in order to be used in case this activity will be resolutive, so we can send the file to Dowson and/or PMDG for hardening or bugfixing or simply knowledge sharing.

Thanks!

SOLVED

PMDG support team, and Scandinavian13 put me on the right path.

It was a FSUIPC (strange) issue.

I've removed mapping of those 2 events:

EVT_CONTROL_STAND_ENG1_START_LEVER70320--- 0: Idle 1: Cutoff

EVT_CONTROL_STAND_ENG2_START_LEVER70321--- 0: Idle 1: Cutoff

from my SAITEK double throttle kit and the aircraft restarted working flawlessy.

Now i have reinserted the 2 events again into FSUIPC (first attempt without deleting the whole config, only the 2+2 buttons related to fuel cutoff) and it's working normally again

Dunno why, old config reported:

2=P1,19,C70321,1     -{Custom control: <70321>}-
3=P1,18,C70321,0     -{Custom control: <70321>}-

while new one, with buttons ordered at the end of file, reports

45=P1,18,C70321,0     -{Custom control: <70321>}-
46=P1,19,C70321,1     -{Custom control: <70321>}-

Disregard, after reinserting into FSUIPC both commands and restarting, it's not working anymore... bug?

Try contacting FSUIPC support, or just use FSUIPC to map controller buttons to key commands and set up the key commands for fuel cutoff switches using PMDG Option menu (I do this for all my PMDG aircraft).