What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Weird one - starting issue

Sportquattro

Well Known Member
Hi folks,

Had a very strange problem at the weekend. Got the aircraft out of the hangar, did a thorough pre-flight inspection, got in, turned on Master Switch, once EFIS was booted, turned the key to start position and engine fires straight up as usual. idled as it normally does. Completed our post-start checks, called for taxy to go get fuel, then once at the fuel farm, shut down normally, refuelled to full on both tanks, got back in, pre-start checks, master on, EFIS booted, turned key and absolutely nothing happened.

EFIS shows good battery charge, recycled the master switch and same problem still. Checked and CBs, all were good. Called tower on the radio and got OK to drag aircraft off the pumps to nearby D with assistance of airside opps, who then gave us a lift back to hangar to get some tools.

Upon returning to aircraft, I got in and thought I would have one more go, low and behold aircraft fires right up as it usually does.

Taxied back to hangar, shut down, waited ten minutes, and went to re-start, again no issues. Repeated this three times all without issue. Went flying for an hour, and got back, shut down, restarted with no issues.

I am therefore at a loss as to why it all of a sudden it refused to do anything when the starter key was turned but was fine 20 minutes later.

Nothing appears to be loose, broken or otherwise U/S on the aircraft so if anyone has any thoughts I'd be keen to hear them.

Aircraft is a RV9A with a O-320-D2A engine with 2 slick magnetos.

Thanks in advance
 
Did you get any "click" from the starter when you tried turning the key? Like the starter gear was trying to extend/engage but wouldn't? If not, that suggests something electrical like the switch.

The key-switches are known for getting flaky with age, which is why I replaced mine with toggles for each mag and a momentary toggle for the starter.
 
Did you get any "click" from the starter when you tried turning the key? Like the starter gear was trying to extend/engage but wouldn't? If not, that suggests something electrical like the switch.

The key-switches are known for getting flaky with age, which is why I replaced mine with toggles for each mag and a momentary toggle for the starter.

Hi Snowflake,

Thanks for the reply, I don't get anything, no click, nothing. My initial thoughts were the ignition switch had gone belly-up and if it happens again I quite like your suggestion of Toggles for the mags and a momentary toggle for the starter as an inexpensive replacement solution.
 
I also have a 9A with an O320-D2A and had a similar situation. I am a hair shy of 1000 hrs on her and she has been like clockwork until about 2 months ago. Turned the key on and nothing. Sat there perplexed and jiggled the back side of my starter switch, and she started right up. In my case the mounting ring had become slightly loose and after tightening, no more problem. If you have a similar set up, check the tightness of the ignition switch to the panel. It may help. Steve
 
start with checking the easy stuff.

Check for a loose wire to the S terminal on the start relay, terminal on the back of the switch, etc. Could be a simple as a loose nut on a stud. Could also be a situation where an unsupported wire has vibrated until the strands broke and became intermittent inside the insulation. Wiggle the wire while checking continuity.

If that's not your problem, then you can dig into the more complicated stuff
 
Check the key switch wire connections.

I had a similar problem with a key switch. The screw holding the starter wire fell out and the ring terminal was touching the key switch contact only due to wire strain relief on the bundle. Sometimes would start, sometimes not.
 
Strong vote for the starter relay, I had the exact same thing happen to me on and off for a few flights, always started after some cool down time. I chased everything in the starting circuit and it finally ended up being the started mounted relay. Luckily I was able to pick up a Ford Crown Vic relay up for $40 and all was good.

Actually a common issue, many report the relay going bad around 200 to 300 hours.
 
As others have said , suspect the starter solenoid or other starter relays that may be in the circuit. Also you may want to look at the wiring diagram and see if the Master could also be preventing you from getting that voltage to the starter solenoid. Mine is wired such that if the master is OFF the started key will not engage the starter. Not all are like that. Master switches are common for bad contacts especially the red split Cessna Master switches lot of us use.
 
No Click or Thunk?

Like others, I experienced the "bad" Starter Solenoid (the big one that rides shotgun on the Starter) syndrome. It seemed to happen more when hot, and I could hear the "clunk" of the Starter Relay.

This leads me to believe that the OP's issue was key-switch/button-switch related.

$.02 chipped in...
 
The starter relay grounds itself to the firewall via it's mount points. If there is a poor electrical connection (corrosion) in the rivets holding the relay to the mount bracket, it may not pass enough current for the coil to pick the relay, resulting in... nothing. No click, no pop, nothing.

The starter relay is typically mounted low center on the firewall, and if you can reproduce this problem hold the keyswitch in the "start" position and reach to the firewall with your right foot, and push/tap on the firewall. If you suddenly get engine rotation, you've found the culprit.

Happened to me at about 200 hours.
 
Wiring

I had a similar problem with my 9A.
Started poorly and traced it to the heavy wire going to the starter.
When I took hold of it the wire came out of the crimp in my hand
Easy fix!
Check out the wiring before spending money
 
Three most likely culprits

Something in the key switch or the associated connectors are failing to get power to the first solenoid for activation (silent)

The external solenoid mounted on firewall is either not moving the piston (silent) or is moving the piston, but the contactor faces are not mating properly (hear clicking) and therefore the power doesn’t get downstream

Most starters have an internal solenoid that works just like the external one. See above

All of these can be intermittent and will be difficult to narrow down until you can replicate it. You can start swapping parts to get ahead of it, but unless you replace them all there is no guarantee it won’t happen again. If you wait for it to reappear, you could get stranded. There are some testing methods to help but beyond the scope of a post


Larry
 
Last edited:
Back
Top