Starting Issues

Discussion off all the ADs.
User avatar
paulmilo
Posts: 153
Joined: Sun Jun 03, 2018 11:03 am
Based: YMNG
Tail Number: KXY
Certificates Held: PPL

Starting Issues

Post by paulmilo »

Minor issue, but annoying. Stalling after start.

I’m finding that the aircraft fires up and then dies within a couple seconds when cold. The only way to stop it from doing this seems to be set a power setting which is too high (1300rpm).

I typically start with fuel pump on auto, but I have tried it set to on, but makes no difference. Once started and running for 15 seconds or so, you can turn the aux fuel pump off and it continues to run fine, so I assume the engine pump is working...although I cannot recall what the fuel pressure is at this point, although I don’t typically look at fuel pressure when idling because it is so low.

It feels like fuel starvation, but not certain. Once it has been running for 15-20 seconds it’s fine. You can set the aux fuel pump to auto and bring it back to 1000rpm. Initially though, if you want it to keep running it wants 1300rpm thereabouts.

Could this perhaps be a weak aux battery? Or a precursor to some other problem?
———————
Milo VH-KXY
Australia

Bigphoto
Posts: 191
Joined: Fri Jun 02, 2017 12:40 pm
Based: KLKU
Tail Number: N207AU
Certificates Held: Commercial airplane single/mult IFR, ATC
Contact:

Re: Starting Issues

Post by Bigphoto »

my two cents: I continue to have that issue until I changed the way I start the engine: I turn the key until pump come on for 10 seconds with the fuel pump running and start mine initially at 1200 or so and then after it starts if it hesitate like its going to quit bring throttle all the way back and it stays running at about 800 RPM and I leave it there for about 45 seconds and then can push the throttle up to where I want it. It only happens below 50 degrees....no issues starting it in warmer temperatures.

User avatar
paulmilo
Posts: 153
Joined: Sun Jun 03, 2018 11:03 am
Based: YMNG
Tail Number: KXY
Certificates Held: PPL

Re: Starting Issues

Post by paulmilo »

Thanks, I’ll give that a shot.

It is opposite to what I have been doing which could be flooding the motor, so definitely worth a try.
———————
Milo VH-KXY
Australia

tafisama
Posts: 40
Joined: Wed Dec 18, 2019 9:09 pm
Based: Adelaide,SA
Tail Number: XLY
Certificates Held: PPL

Re: Starting Issues

Post by tafisama »

Mine does the same at times.I have been thinking it`s probably some spark plus that are gone.Keep us posted on you findings

frfly172
Posts: 515
Joined: Mon May 19, 2008 1:07 am
Based: Kowd ksrq
Tail Number: N591xl
Certificates Held: ATP MEl sel
Location: Boston Area bradenton florida
Contact:

Re: Starting Issues

Post by frfly172 »

Try doing the prime and start with the pump on. Let the motor stabilize before shutting the pump off.

User avatar
XL2driver
Posts: 115
Joined: Mon Jun 23, 2014 10:28 pm
Based: 7FL6
Tail Number: NXXXX
Certificates Held: Comm, CFII, Airplane MEL&S
Location: Port Orange, Florida, USA
Contact:

Re: Starting Issues

Post by XL2driver »

SUGGESTED READING -

This might be of help -
Please see my (long) post dated Sun Jun 23, 2019 3:41 pm in reply to "Starting Issues" at -

http://www.libertyxl2.creativephotog.co ... 083f#p8050
-------------------------------------------------------------------------------------
Maintain VSO+1

User avatar
paulmilo
Posts: 153
Joined: Sun Jun 03, 2018 11:03 am
Based: YMNG
Tail Number: KXY
Certificates Held: PPL

Re: Starting Issues

Post by paulmilo »

Thanks everyone, I’m thinking that I am perhaps setting too much throttle upon start. When I am released from home arrest [or maybe before ;-)], I will give BigPhoto’s approach to reduce (not increase) throttle if it hesitates.

I doubt it will be the plugs as they have always seemed quite good.

Thanks Paul (XL Driver). That long post was useful esp as it pertained to hot starts. I think it was also your suggestion to double prime via the key being switched to ‘both’ two times before starting. That also made a big difference to the engine firing first attempt. This is a slight variation on the problems I was having. The engine now always starts and even when it stalls, it re starts fine. I just want to avoid having to re start by not letting it stall in the first place.
———————
Milo VH-KXY
Australia

User avatar
XL2driver
Posts: 115
Joined: Mon Jun 23, 2014 10:28 pm
Based: 7FL6
Tail Number: NXXXX
Certificates Held: Comm, CFII, Airplane MEL&S
Location: Port Orange, Florida, USA
Contact:

Re: Starting Issues

Post by XL2driver »

Glad it was of some help.
However "double prime via the key being switched to ‘both’ two times before starting. " = not my suggestion or recommendation. :-)
-------------------------------------------------------------------------------------
Maintain VSO+1

User avatar
paulmilo
Posts: 153
Joined: Sun Jun 03, 2018 11:03 am
Based: YMNG
Tail Number: KXY
Certificates Held: PPL

Re: Starting Issues

Post by paulmilo »

So Paul, to be clear, are you

(a) just not claiming ownership to the recommendation; or
(b) recommending that it NOT be done?

If the latter, is there are reason? Risk of backfire or something else?

Cheers
———————
Milo VH-KXY
Australia

tafisama
Posts: 40
Joined: Wed Dec 18, 2019 9:09 pm
Based: Adelaide,SA
Tail Number: XLY
Certificates Held: PPL

Re: Starting Issues

Post by tafisama »

Re: Partial DIY Annual Begins Tomorrow
Post by N645XL » 02 Feb 2015 06:55

Post annual follow-up Part 1: When we did the annual a few weeks ago the spark plugs provided the lesson for this update. I had significant cold weather starting issues prior to the annual inspection. She just didn't want to fire up. During the annual they discovered I had one spark plug with a lead bridge between the electrodes and two had marginal resistance near the 5,000 ohm range (but still passable). Per my research new spark plugs have a resistance of between 1,000 and 1,200 ohms. They marked the two marginal plugs and reinstalled. Because of the issues I had running a diagnostic before the annual, I ran the diagnostic after they were finished with their part. The engine (even after coming out of a warm hangar) wasn't easy to start and the hot-idle portion near the end of the diagnostic sequence showed a CHT dip in one cylinder as the engine stumbled. Everything passed the software check and the IA signed off the annual. I did tell him I was going to go ahead and replace all the spark plugs.

Last weekend I had the new spark plugs in-hand with my modified spark plug socket and freshly calibrated torque wrench then proceeded to do my first spark plug R&R on an aircraft. It all went well. It was too late to do a test flight but I did a run-up which went fine. I didn't have a chance to fly it until yesterday. The temperature yesterday was as low as 13 degrees F. The plane was cold soaked. I applied some engine heat for a while and then pulled her out fully expecting to wrestle her to an engine start. Two blades and she fired up like it was summer-time. Wow. Of course I sat there forever waiting for the oil temp to come up but everything to include a smooth idle (no stumbling) made me feel like it was a new airplane. Lesson learned: The XL-2 doesn't seem to like spark plugs approaching end of life even if the book says they're still acceptable.

Part 2: During the annual I mentioned to the IA about the cold oil temps of about 80 degrees or so while flying on cold days. He perked up and said the oil temps should be much higher. He had the sheet metal specialist fashion a plate. It covers the oil cooling duct that runs from the top of the engine down to the oil cooler. It's held on with two nutplates and machine screws. The longest part of taking it off or installing it is the upper cowling. It's simple in it's design and operation. My three flights since have seen oil temps from 168 to 198 degrees (well within the green arc). The outside air temps have been from freezing to well below freezing so it is doing its job. The head of the machine screw on the right is accessed near the top of the lower cowling. A stubby screwdriver makes access easy. P.S. When I can migrate south with the weather's temperatures I plan to retire this plate. :-)

Post Reply