Slow start issue in Piper Lance

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Code90

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Code90
Have on two separate occasions had same issue. Flying '77 Lance (Lycoming 540) and have had slow starts when engine hot.

Normally when we crank it, it will not freely spin the prop on first turn of key. Goes about 1/2 way around and stops. Release the key and turn it again, and it will windmill until it fires up.

Flew in 2 hours to customs in KFPR. Cleared customs. Ate meal at Tiki Hut. Came back out and used hot start procedure in POH. (Aux pump on, throttle 1/2", mixture off, crank until catches and then richen mixture). When I turned key, the prop went less than 1/2 way around and stopped. Released key, went about as far. Several tries and it would not spin. Seemed like it didn't have the power to spin around. Waited and retried after a minute or so, would try but never totoally spin around. Got less and less movement with each try. Finally after multiple tries, it spun around fully, motor coughed to life, richened mixture, and ran fine for next 3 hours back home.

This happened first in January. We assumed it was a battery issue (was 4-5 yrs old). Replaced battery. Happened again yesterday. Now I'm looking for suggestions. Today I checked the battery. Terminal wires are attached tightly and clean. Voltage was 12.5 sitting, 10.5 cranking. When running, the engine monitor reports 13.5 volts. Plane has been flown at least weekly. Just out of annual.

Thoughts?
 
When was the last time your starter was cleaned/inspected? Ideally, that should be on a 500-hr inspection schedule (unless your starter mfr says sooner) just like your vacuum pump, mags, and other accessories. Sounds like worn out brushes in the starter to me...
 
I will second the starter reply above. Mine would only turn over until the compression stroke and then I'd have to release the key and try again for it to work. I put in a new SkyTec and I love it! Starts right up with no issues now.
 
Code90 said:
Have on two separate occasions had same issue. Flying '77 Lance (Lycoming 540) and have had slow starts when engine hot.

Normally when we crank it, it will not freely spin the prop on first turn of key. Goes about 1/2 way around and stops. Release the key and turn it again, and it will windmill until it fires up.

Flew in 2 hours to customs in KFPR. Cleared customs. Ate meal at Tiki Hut. Came back out and used hot start procedure in POH. (Aux pump on, throttle 1/2", mixture off, crank until catches and then richen mixture). When I turned key, the prop went less than 1/2 way around and stopped. Released key, went about as far. Several tries and it would not spin. Seemed like it didn't have the power to spin around. Waited and retried after a minute or so, would try but never totoally spin around. Got less and less movement with each try. Finally after multiple tries, it spun around fully, motor coughed to life, richened mixture, and ran fine for next 3 hours back home.

This happened first in January. We assumed it was a battery issue (was 4-5 yrs old). Replaced battery. Happened again yesterday. Now I'm looking for suggestions. Today I checked the battery. Terminal wires are attached tightly and clean. Voltage was 12.5 sitting, 10.5 cranking. When running, the engine monitor reports 13.5 volts. Plane has been flown at least weekly. Just out of annual.

Thoughts?
Click to expand...
Is the cranking voltage recorded at the battery or starter?
Pretty good troubleshooting for starter/starting issues here: http://www.skytecair.com/Troubleshooting.htm
 
Before you blame the poor starter, consider what is supplying voltage and current to the starter. The starter relay (solenoid) routinely routes hundreds of amps through it and the contactor plates get arced/burned with every dis/connect. If you ever open up an older starter relay, you will be amazed at how burned it is and how much resistance it can pose in the circuit, thus not allowing full voltage and current to reach the starter motor.

Hope this helps.
Lou
 
I have a similar issue on the first start of the day in my Lance. Have replaced the battery (old battery turned out to be still very good - both Concordes) and replaced the starter with a new Sky-Tec version. Still does it. On the first start of the day it will spin about 1/2 a turn, pause for a second, and then start without fail. Just seems odd. On successive starts, the starter spins the prop very strong. I've been told to check the starter relay, but just haven't got around to it yet. Plenty of other things going on in life and such...
 
If the engine stops right before a compression stroke sometimes that is enough to impede the starter. Its just harder to start from there. Something like that might explain it.

Other than that, battery, cable, battery charging. Charge the battery up good and see if that fixes it.
 
Any one of the components between the battery and starter could be a problem as can the cables. Then there's the ground return path. Follow the skytech chart and you may find the problem.
 
Do you have aluminum cables to your starter, or are they copper? A common issue is that the aluminum cables, as they age, increase in resistance and are unable to deliver the power to the starter that's needed, even with a brand-new, fully charged battery.
 
Yes, verify your voltage at the starter during cranking, you could have a cabling issue, a starter contactor (solenoid) issue, or a starter issue.

Another question, do you have impulse couplings on both mags? I've seen instances where a magneto was firing before TDC on the compression stroke and stopping the motor dead as well. Sometimes it is a bird that only has one impulse coupling, other times it is because the impulse coupling is worn out...

Hopefully, you find a solution that isn't too expensive! :)

-Dana
 
Final Solution: New starter.

Checked voltage at starter. Despite 12 V at starter, nothing turned. Starter replaced (was 15 yrs old) with new Skytec and now cranks like crazy.
 
Code90 said:
Final Solution: New starter.

Checked voltage at starter. Despite 12 V at starter, nothing turned. Starter replaced (was 15 yrs old) with new Skytec and now cranks like crazy.
Click to expand...
Glad you checked it right and replaced only the part that was faulty, kudos. (most mechanics don't bother and just slap new parts on it until the problem goes away - happened to my "new" airplane before I bought it, from reading the log books)

And I just ended up doing exactly the same thing you did, the 18-y/o starter went poop and I needed a new one. I disassembled the old one and have pictures that show the commutator brushes worn down to the braided wire. No wonder she wouldn't crank!! :)
 
I will try to post two videos. First one was the old starter when it still worked. Second one is new starter.
 
BigBadLou said:
And I just ended up doing exactly the same thing you did, the 18-y/o starter went poop and I needed a new one. I disassembled the old one and have pictures that show the commutator brushes worn down to the braided wire. No wonder she wouldn't crank!! :)
Click to expand...

That's why there's usually an item on the manufacturer's inspection check sheets that asks for the brushes to be inspected every 200 hours. Takes a few minutes in most installations. Still, most don't get it. The new PM starters don't need it.

Always amazed that so many owners run stuff until it fails, often at a really inconvenient time. Spoils the trip and ends up costing way more than preventive checks and maintenance would cost.
 
Sounds like the new starter got you up to speed. As posted above, if one has aluminum battery cables, the copper replacements crank MUCH better.
 
Dan Thomas said:
That's why there's usually an item on the manufacturer's inspection check sheets that asks for the brushes to be inspected every 200 hours. Takes a few minutes in most installations. Still, most don't get it. The new PM starters don't need it.

Always amazed that so many owners run stuff until it fails, often at a really inconvenient time. Spoils the trip and ends up costing way more than preventive checks and maintenance would cost.
Click to expand...
Agreed. It should be part of some kind of preventative maintenance. However, on this specific airplane/engine, it is not easy at all to get to the starter, let alone the brushes. So I can imagine why the mechanics didn't bother.
And this is a new (to us) airplane so we already got it with a slow cranking starter and I was just starting to troubleshoot all the "little things" that came with the plane. This one turned into a big thing pretty fast and I am glad it happened at the "home 'drome". Whew.
We just got back from a nice beach trip yesterday, I sure was glad that she cranks like a trucker now! :)

Go fly, people! :)
 
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