Fuel injection problems yesterday. - Page 2

hugo · #11 10-07-2013, 05:53 AM

I have same experience ,my lightspeed died,for excess of temperature,this happen 2 years ago,when call the company ,they offer for a fee,they will replace the board for one more resistant to heat,but temperature was Not the problem,according to them,since then ,I install in the cover a fan with temperature control,always on,never again the problem.
Hugo

Smilin' Jack · #12 10-07-2013, 11:57 AM

Glad you made it back on the ground with no further issues. I do not have any experience with the electronic ignition but others seem to have a probable cause.

Good news is if it was the EI at least you know that it will fly on one. With the number of failures noted just by RV's on the EI, I guess I am glad I stuck with the 50 year old mags...

Smilin' Jack

pierre smith · #13 10-07-2013, 12:36 PM

I'm trouble shooting it as we speak.

I spoke with Klaus this morning and he said that his EI is extremely well protected against spike voltages and that it can operate down to 5 volts? I had 11.4 when I landed and the alternator has been taken to a local Mennonite repairman. It may well be the mag. We shall see.

The battery is being trickle-charged and I'll know more when the alternator is re-installed.

Best,

rocketbob · #14 10-07-2013, 12:58 PM

I recall having a conversation about low-dropout voltage regulators with Paul Lipps (designer of the Lightspeed ignition), and he told me the Lightspeed ignitions will run down close to 5V.

Funny that I also have a Mennonite friend who works on alternators and starters

Toobuilder · #15 10-07-2013, 01:33 PM

After a bout with some ignition issues (self induced), I am now in the habit of performing an enroute "mag check" in addition to the normal end of runway runup. As discussed on this site and elsewhere, the enroute check (LOP in my case) provides a far better indicator of ignition health than the nearly worthless end of runway check we've been doing for decades. That said, any uniform change in EGT should have included this check as the initial troubleshooting step. Be aware however, that if we are right and you have a dead ignition, the engine would go very quiet when you isolate L and R. Be over an airport or at least be ready for it!

Toobuilder · #16 10-07-2013, 01:36 PM

Quote:

Originally Posted by Smilin' Jack

...With the number of failures noted just by RV's on the EI, I guess I am glad I stuck with the 50 year old mags...

...and it is the number of mag failures on all GA aircraft that drove me to to dump the ancient technology in favor of the EI.

pierre smith · #17 10-07-2013, 02:00 PM

Quote:

Originally Posted by Toobuilder

...and it is the number of mag failures on all GA aircraft that drove me to to dump the ancient technology in favor of the EI.

Exactly. With 6 years and 550 hours of use, plus incredibly fast hot starts, the Lightspeed system has been totally trouble-free. I watched a British Bulldog trying to get started for an hour on Saturday and mine fired up with 11.7 volts showing, instantly. Klaus's E.I. is one hot mama....so much so that you have to use his ignition leads...shielded aircraft leads won't cut it.

Best,

Dean Pichon · #18 10-07-2013, 03:16 PM

A couple of weeks ago, I was flying along happily and then noticed my (one channel) EGT reporting 1400+ temperatures. Fuel flow was very high (12+ gpm), but power was low. Throttle or mixture adjustments made everything worse.

I made a precautionary landing at the nearest airport and removed the cowl to look. I found 2 loose fuel injectors! The body of one injector was loose and the B-nut on another was loose. Both were dumping fuel into the cowl as evidenced by large blue stains.

I left the plane with the local FBO and asked them to remove, inspect, and replace all the injectors and review the fuel system. One the injectors were re-torqued, everything worked well again. I have made a few (local) flights since and, so far, everything is behaving beautifully.

Your problem sounds a little more complicated, and every bit as scary.

Good luck,

RV10inOz · #19 10-07-2013, 03:19 PM

Pierre, I do not know about hot start issues, we run two mags and they start first go all the time, and as you would appreciate, we are not in a cold climate here. 95 degrees F yesterday, and it is only spring!

Back to what you experienced, when one mag/EI goes off line you get a rise in EGT, and a slightly lower CHT. The reason for the higher EGT is due to less expansion of the gasses as the peak pressure is now occurring further from TDC than before thus has more volume and lower pressure. Same reason why a lower compression engine runs a higher EGT.

There was no reason to change the F/A ratio at all, in fact by going richer the only thing you did was reduce HP, waste fuel, gunk up the engine etc.

Toolbuilder is correct in saying the best mag check you can do is one done in the cruise LOP at the highest power you can attain (WOT/2300-2500/LOP) and best to do it near TOD, so that you have some trouble shooting time in flight before you land.

As for being above an airfield, I disagree, but if it makes you feel warm and fuzzy the first couple of times sure go ahead. If you have a dead mag, the engine flames out, remember this! If you are pumping fuel and air into the exhaust and you were running ROP, their is a good chance you will have a nice "after fire" mixture in the exhaust. So pull the mixture to idle cut off, go back to the good mag, and slowly sweep the mixture back in. Engine relights and away you go knowing you have one mag to fix.

If running LOP there is not much chance of harming anything, you might get a few rumbles but there is nowhere near the fuel available in an expanding volume of space to cause a major event.

Have a look at a good mag check in flight, WOT and LOP at FL130, this is no doubt the kind of result you saw.

http://www.youtube.com/watch?v=s155lSZxsKQ

By the way, you really would learn a heap and undo all those old habits of what we were once taught with a weekend holiday in Ada OK. Yeah I know it is not a tourists bucket list entry but for piston pilots it has one gem.

Be keen to know the outcome too Pierre, be it EI or mag. Just also go looking at the P leads and make sure that one is not being grounded, that shuts em down pretty effectively too!

Smilin' Jack · #20 10-07-2013, 04:18 PM

As always a nice video and education for those of us who have not flown piston engines in a while.

I know that a lot of folks are sold on EI and perhaps some day we will move that direction. But I got to get it flying and when we were building the engine EI were going to increase the cost more.. We did go the GAMi injectors which most folks really rave about.
Thanks for video David

Jack