912 ign probs

[bones]

Guys, i hoping for a few hints as to what to look for in the following problem.

 

I have to fly out to a property to look at a 912 that looks like it has dropped an ign, the no.2 side appears to be most of the time dead, it is at this time a little intermittant, but he says he can get it to do it most times, as in switch off no1 with no2 still on and the motor dies.

 

I have stolen a set of black boxes off and old motor in the hangar here to take and try, as well as testing the ign circuits from black boxes to switches, for a short to earth with my multimeter.

 

Is there any other ideas i should look for?

 

Just that i have never had a problem with this, ever, i spoke with Floods yesterday and they were not sure either, not a normal problem, they want the boxes sent down to check them.

 

Hoping the worst thing i find is one of the boxes are shot, otherwise if it is deaper than that, ie. no signal from the motor well lets just say thats an area i dont want to go to.

 

I leave in the morning at daylight so any tips would be great, and the motor only got approx 200hrs on it at this time.

 

 

[FlyingVizsla]

My husband had something similar - on the run up test it ran rough, but not missing, on one ignition. Fixed it by using switch grease on all the connectors between the modules & coils etc.

 

Sue

 

 

[bones]

Thanks Sue, I should have put Gals in the intro as well. I will see what i find in the morning.

 

 

[bones]

Well looks like the B black box was faulty from the looks, refitted the old 2000 hrs boxes and runs a treat.

 

Ill send them off to get tested to be sure.

 

 

[planesmaker]

I have had the wire broken(twice it has happened) from pickup to ign box, I would be surprised if it is the box itself. sorry a little late with the reply only just logged in. Regards Tom

 

 

[planesmaker]

I should add, just near the connector at the top, there was enough wire to strip and put in new connector. Tom

 

 

[bones]

Well since i got back spoke to another guy who had the same thing happen, the black box failed, it was very intermitant also, so i hope it is all it is, very tall timber and rock where Mike flys, but all the ground run up and tests i did this morning could not find a problem, we will know by the end of the week after Floods tests them.

 

 

[planesmaker]

Please let us know if they find a fault, good to know for future reference. Tom

 

 

[bones]

Well the black boxes checked out fine at Floods, so i need to get back there and refit the boxes to the original motor to see if it still playing up or if it was a bad connection that fitting the other boxes fixed

 

Will let you all know what happens.

 

 

[planesmaker]

Well the black boxes checked out fine at Floods, so i need to get back there and refit the boxes to the original motor to see if it still playing up or if it was a bad connection that fitting the other boxes fixed Will let you all know what happens.

Bones I had an interesting discussion today with one fellow has both boxes fail together. Flying good one day next day nothing Floods have told him both ign have failed. Another fellow told me of a tecnam coming into Avalon where both ign failed in flight. Seems there could be more to these failures than 1st meets the eye. Very unlikely for both to fail at the same time unless something common is happening to both but they are both on individual circuits. Very strange indeed. Have to look into this further. Regards Tom

 

 

[jakej]

Bones I had an interesting discussion today with one fellow has both boxes fail together. Flying good one day next day nothing Floods have told him both ign have failed. Another fellow told me of a tecnam coming into Avalon where both ign failed in flight. Seems there could be more to these failures than 1st meets the eye. Very unlikely for both to fail at the same time unless something common is happening to both but they are both on individual circuits. Very strange indeed. Have to look into this further. Regards Tom

Tom, the ignition switch is a common point for some aircraft eg the Acs key type - I wonder if the switch is the problem here ?

 

 

[Tex]

Tom, the ignition switch is a common point for some aircraft eg the Acs key type - I wonder if the switch is the problem here ?

That's what I was thinking check the switches...

 

 

[dazza 38]

The Tecnam Echo that had dual CDI failure late last year near Beaudesert had seperate CDI switches which in its particular case is a concern. I would suspect it would be more likely for dual CDI failure via a Single ignition switch than seperate CDI on/off toggle switches.