Mailing List flyrotary@lancaironline.net Message #48214
From: Jeff Whaley <jwhaley@datacast.com>
Subject: RE: [FlyRotary] Mixture condition
Date: Fri, 18 Sep 2009 13:04:33 -0700
To: Rotary motors in aircraft <flyrotary@lancaironline.net>

John, let’s clarify your previous statement “ I turned of the fuel pump and with the injector switch's off the engine continued to run until the fuel press was down to 17 pds. and quit.”  Do you really mean BOTH INJECTORS are OFF and the engine keeps running? Does your system automatically switch to carburetor if the fuel injection system is disabled or fails? Or do you have to take manual intervention to switch from one to the other?

Your manifold pressure and EGT behavior are normal for a misfiring engine.

I doubt there is anything wrong with the injectors.

There was a lot of discussion about 2 months ago on primary and secondary injectors above and below staging point – you may want to review some of that. However, if your EC2 is wired as per Tracy’s recommendation it doesn’t matter whether PRI, SEC or BOTH are on below staging – the DPDT switches take care of that, but above staging BOTH should be ON.  You also need to know where your staging point is in terms of manifold pressure. Default is ~15”; I increased mine to 17” and some guys have set it to 20”.

Steve’s comment about the pressure regulator may be the key …

Jeff

 

From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of John
Sent: Friday, September 18, 2009 3:14 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Mixture condition

 

Jeff,   I went back out and ran the engine again.  The fuel pumps are T-eed of after the gascolator and go to the separate fuel systems, the Weber is on top of the engine, above the fuel level in tank.  I ran the engine on fuel injection and it was working fine when it was cool.  I shut off the primary injector switch and the engine quit immediately like it had always done in the past, but when it go warm (190) and started missing, it ran a lot better with the injector switch off and when I turned the injectors back on it was missing terrible and this time I noticed that the Manifold pressure creep up from 13# to 24# and the EGT on the #1 rotor went down to the bottom of the scale.  I tried the scene 3 times and the results were the same each time with the primary or secondary injector switches on.  Like wise it is a big question to me, as to the change in function in the injector switches. 

 

Could it be that the computer is flooding the #2 rotor and the reason it doesn't quit when I turn the mixture to full lean at 2000 rpm.  It does run a little better at higher rpm's (like 4000).  

 

The injectors were reconditioned ones that I got from Bruce T and I'm thinking that the #1 primary injector may not be working when it gets hot.  On the other hand, doesn't the secondary system take over, or is that only at higher rpm's.

 

If it is a ground condition, it seems like it wouldn't wait until the engine is hot to quit working, it would be happening at any time.  JohnD

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