VAF Forums

VAF Forums (https://vansairforce.net/community/index.php)
-   RV General Discussion/News (https://vansairforce.net/community/forumdisplay.php?f=2)
-   -   Fuel injection problems yesterday. (https://vansairforce.net/community/showthread.php?t=105067)

pierre smith 10-06-2013 05:52 AM

Fuel injection problems yesterday.
 
Coming back from the Race to Ridgeland in South Carolina yesterday, my -10 suddenly showed highly elevated EGT's for no apparent reason. I had been running 23"/2350 RPM and ROP, around 1330 EGT and all of them suddenly went to 1410/1430 without me touching anything. I had been running 15.4 GPH, so I enriched the mixture to lower the EGT's to near 17 GPH.

They did come down a little, to just under 1400 degrees with fuel flow at 17 GPH. The CHT's had not risen at all during this episode, so I suspected a Dynon problem. (D-120 EMS).

I also considered the fact that I may have developed a fuel leak under the hood, so I braced myself for a possible in-flight fire and was ready to shut the fuel off. If the engine was truly starving at 17 GPH, all of the fuel must not be reaching the injectors, hence the high EGT's, no?

I remembered Todd Swezey's cockpit fire and explosion at Ridgeland a few years ago, so I decided to NOT touch the flap switch in case there was fuel in the tunnel, and landed fast and long at home.

I will de-cowl the airplane and I'll report back.

Opinions anyone?

Best,

plehrke 10-06-2013 06:02 AM

Quote:

Originally Posted by pierre smith (Post 813935)
I had been running 15.4 GPH, so I enriched the mixture to lower the EGT's to near 17 GPH.

They did come down a little, to just under 1400 degrees with fuel flow at 17 GPH. The CHT's had not risen at all during this episode, so I suspected a Dynon problem. (D-120 EMS).

What was the reason for enriching? Was it just to see what would change? EGT of over 1400 do not mean anything is wrong. When you enrichened what did the CHTs do?

pierre smith 10-06-2013 06:18 AM

Philip, the EGT's were at peak...not good, so I enriched it to lower them. Strangely, the CHT's hadn't changed during all this.??? The puzzling thing is that all of the EGT's rose simultaneously without me having done anything, by almost 100 degrees.

Best,

Weasel 10-06-2013 06:29 AM

mags
 
Did it run rougher when this happened? If 1 mag goes dead it will do this . Or if the timing somehow changes.

Walt 10-06-2013 06:30 AM

Check the igition system, one of the mags died.

rzbill 10-06-2013 06:32 AM

Pierre,
Isn't that a symptom of one ignition going bad? Ah, others beat me to it.

pierre smith 10-06-2013 06:54 AM

Hmmm...
 
Y'know, I was limpimg home with only 11.5 volts showing and it may well have been the Lightspeed failing,,,hmmmmm? Yep, it was also accompanied by a loss of several MPH, but I thought that the Lightspeed only needed aroun 9 volts, no?

Yep....could be.

Thanks,

David-aviator 10-06-2013 07:54 AM

Quote:

Originally Posted by pierre smith (Post 813946)
Y'know, I was limpimg home with only 11.5 volts showing and it may well have been the Lightspeed failing,,,hmmmmm? Yep, it was also accompanied by a loss of several MPH, but I thought that the Lightspeed only needed aroun 9 volts, no?

Yep....could be.

Thanks,

11.5 volts, Pierre?

You've got an electric problem not a fuel injection problem.

I've had EI and it comes with a double edged sword, its good when all is well but can get mighty weird when all is not well.

Good luck in sleuthing out the problem, with the alternator up and running it may be fixed.

Toobuilder 10-06-2013 08:24 AM

My first thought would also be ignition. I've had one side die in flight and that's exactly what my EGT did as well.

LifeofReiley 10-06-2013 08:34 AM

Pierre,

I think you might be dealing with two issues. The lightspeed will work on 11.5 V but, it sounds like you lost your alt and could have spiked the lightspeed box. Seen it happen a few times. Also check the wiring to the coils for arc at the connectors. :) A dead Mag will cause the EGT issue, but does not explain the 11.5 volt issue.


All times are GMT -6. The time now is 02:22 PM.