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Engine ignition problem

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VETE76

Well Known Member
RV7 with LYC IO360M1A. PROBLEM, it won?t start. I have fuel, air and a spark. Called an A&P and he said there was nothing on the engine to make the starting spark hot enough for starting it. He is only a certified type aircraft mechanic and not really up on our ways. He said an impulse coupler would run upwards of $2500 +.
Also lots more work. Plane is ready to fly except for the engine starting. W&B is done, fuel flow is done etc. the DAR is waiting to issue airworthy cert. what other system can I put on to make this work?
Thanks
Fred
 
First, get another mechanic. Your engine is a certified type. And a brand new mag is less than half his estimate for an impulse coupler.
Check easy stuff first. Are the correct cylinders hooked to the correct high tension leads? Is the ignition switch wired correctly? (check with an ohmmeter that left mag P lead is open, right P lead is shorted, with key on start).
Then harder stuff, like mag timing.
 
Tell us more about your systems and what you have done so far. ie

what type of ignition system?

ignition/start switches?

what type of fuel system?

what have you verified so far?

fuel pressure?

Spark timing?

compression?

I'm sure others smarter than I will chime in soon.

Bevan
 
Bevan said:
Tell us more about your systems and what you have done so far. ie

what type of ignition system? no idea. just 2 mags with 2 wires going to each.

ignition/start switches?
what type of fuel system? elec fuel pump and its putting out per test procedures.what have you verified so far? fuel, air, spark.

fuel pressure? dont know it hasnt started yet. guage reads 25 when i am priming.Spark timing? set

compression? dont know but all indicates lots. brand new motor and when u run prop through u better be strong.

I'm sure others smarter than I will chime in soon.

Bevan
Click to expand...

..............................
 
1. Has this engine ever run (test cell, etc?). If so, has anything changed (ie mag removed and reinstalled, etc) since the run?
2. It would be helpful to know the model #'s of the mags. Your left mag is most likely either an impulse coupled mag or a retard breaker. If it's a retard breaker more than likely you have a weak spark and will need to add a starter vibrator like the SlickStart to augment it's starting ability. However, with a fresh battery, it still could start even without the vibrator.
3. Besides double checking that the ignition leads are connected to the correct cylinders amnd the switch is wired correctly, have you checked the timing?
4. Have you verified that fuel is actually flowing from your boost pump all the way to your injector nozzles?
 
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Auburntsts said:
1.
Has this engine ever run 2hrs (test cell, etc?). If so, has anything changed (ie mag removed and reinstalled, etc) since the run? not to my knowledge. it was ran, crated and shipped to me.2.
It would be helpful to know the model #'s of the mags. left mag 4347 lag 25, rot Ll, rev d. right mag 4370 lag 0, rot L, rev f.[/ Your left mag is most likely either an impulse coupled mag or a retard breaker. If it's a retard breaker more than likely you have a weak spark and will need to add a starter vibrator like the SlickStart to augment it's starting ability.
However, with a fresh battery, brand newit still could start even without the vibrator.
3. Besides double checking that the ignition leads are connected to the correct cylinders, yes they arehave you checked the timing?timing perfect
4. Have you verified that fuel is actually flowing from your boost pump all the way to your injector nozzles?
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yes
........................
 
is the spark there while the starter is cranking the engine? Disconnect P-Lead on left mag and crank it again.. Same for fuel flow... ensure you're getting all those (air, fuel, spark) while you're cranking.. that'd be a start.. (well, the start really would be to get a different mechanic)
 
The answer

Slick 4347 is a retard mag, not an impulse coupled (according to google!).
When you turn the prop by hand, as you go past peak compression do you hear a distinct "clunck" noise from the mag? I'm guessing not.

You need to buy a Slick start and wire it up.
Or replace the magvwith an impulse coupler model.
 
this is a trap a lot of people will be finding since they stopped supply the impulse mags.

What is more they do not supply the slick start as part of the bundle. Crazy hey!
 
Vans isn't even completely clear on this. As I recall when I ordered my YIO-540 from Vans the form had a line for a Slick Start, and said "Slick Start recommended". It should say, "engine won't start without this".
 
The left mag does have a timing retard, just no impulse coupling to boost the voltage. It shouldn't kick back unless the left mag won't produce a spark but the right one can, at the speed the starter can turn the engine.
 
Ok, so impulse mags are not available with a new engine order from Vans?

Slick start is the way to go now? One day I am going to order an engine from somebody!

Bird
 
4247 magneto

I have a 4347 magneto on my RV4. It is a "shower of sparks" magneto and requires a starting vibrator or the slick start equivalent. If it fires, you will get a kick back as it is operating on the advance points which are normally shorted during cranking. This allows the retard breakers to originate the spark at TDC for the start.

A good system, but I'm surprised that a new engine came with it.

Mitch

RV4...just sold

RV!2 slow build
 
BobTurner said:
Slick 4347 is a retard mag, not an impulse coupled (according to google!).
When you turn the prop by hand, as you go past peak compression do you hear a distinct "clunck" noise from the mag? I'm guessing not.

You need to buy a Slick start and wire it up.
Or replace the magvwith an impulse coupler model.
Click to expand...

no clunk...........
 
Think

That I'd call the engine manufacturer and describe the problem to them. They should be more than happy to help you troubleshoot. Good luck - don't do anything in haste and maybe get someone in your area to double check your troubleshooting.

Please let us know what you find.
 
Ok , since it appears your left mag is a retard breaker, is it wired up properly? By that I mean you should have two wires--the normal p-lead and another wire to the retard breaker terminal. My understanding is with a brand new battery it might be possible to get the engine to start, but I wouldn't hold my breath. Even if it does, eventually it won't so adding a SlickStart module really isn't an option IMO.
 
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How energetically is the engine cranking? I have run a Van's engine with no impulse coupling and no slick start for over 6 months before adding the slick start. That was because the battery was a little weaker and it only mattered on a hot start. If it isn't cranking very strongly, make sure you have a good engine to airframe ground strap and try again. I have run into this problem more than once.

And, you will want a slick start.

I don't really understand vans on the mag thing. Dual impulse coupled mags should cost less extra than a slick start, and the starting is a beautiful thing (and you can notice if one mag gets off timing just by listening to the clicks. I've never had a better hot start than with dual impulse coupled mags.
 
Jesse said:
How energetically is the engine cranking? seems strong

I have run a Van's engine I bought this direct from lyc

And, you will want a slick start.

I don't really understand vans on the mag thing. Dual impulse coupled mags should cost less extra than a slick start, and the starting is a beautiful thing (and you can notice if one mag gets off timing just by listening to the clicks. I've never had a better hot start than with dual impulse coupled mags.
Click to expand...

......................
 
ok, we installed a slick start system. now we get a lot of puffs of smoke and a few "bangs" but no start. any more suggestions?
ty
fred
 
Well, it sounds like progress. I wonder if all the previous attempts have left your plugs coated with oil (was it blue smoke?). I'd pull the plugs and have a look.
 
VETE76 said:
ok, we installed a slick start system. now we get a lot of puffs of smoke and a few "bangs" but no start. any more suggestions?
ty
fred
Click to expand...

Sounds like the timing is out on the mags to me. . Check that your mag to engine timing is correct."bangs" and smoke could be the mag firing the fuel/air charge on the exhaust stroke . Did you check the timing with no1 on the compression stroke? That happened to a guy around here with one of those mags. Turned out to be 180degrees out to the engine.
If its a new engine it could also be that the plugs got covered with preserving oil when you started cranking it and are now all gummed up. That also happened around here on an rv7 with new engine.
 
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Start?

I would think if the engine ran on a test stand and only time and hooking up a ignition switch is the difference, then I would disconnect both "P" leads and crank the engine, you can shut it off with the mixture if it starts. Please make sure you have full travel at both ends of the cables with a little bounce at the end of both the throttle and the mixture. Had a friend with his first start about a year ago and his ignition switch was grounding in the run position but not during start. One thing you need to do is to take the injectors out and just spray carb clean through them, also run your boost pump for a couple of seconds with rags under the ends of the fuel lines while the injectors are out. I have started a couple of new (pre ran) IO 360's and they had little bits of stuff in the injectors and the engine's did not want to run. Good luck, be careful out there.

RT
PS. Does your left mag have a spacer (easy to see, it's about an inch thick) between the engine and the mag?
 
VETE76 said:
ok, we installed a slick start system. now we get a lot of puffs of smoke and a few "bangs" but no start. any more suggestions?
ty
fred
Click to expand...

Please find someone locally to help you resolve your problems, this is the kind of thing that will get you in big trouble on that first flight if you don't know what you are doing :eek:
 
Walt said:
Please find someone locally to help you resolve your problems, this is the kind of thing that will get you in big trouble on that first flight if you don't know what you are doing :eek:
Click to expand...

+1 on that!

This is beginning to sound very much a "back to basics" situation....

Is the timing correct?
Are the high tension leads routed properly?
Are the p leads/ignition switch terminals correct?
Are the plugs clean?
Are the fuel lines clear?
Is the fuel fresh?
Are the valves operating?
Etc, etc, etc....

These engines are dirt simple... Any competent A&P should be able to verify all of this and more in a few minutes.
 
I have seen a problem before where the leads in the harness were the wrong lengths, so they were on the wrong plugs. The leads will all have a cylinder number as well as T or B. the engine has cylinder numbers at the base of the cylinders on the case. Make sure you have those right, because that could definitely cause the problem you are seeing. If it was run on a test stand, then it should be something simple. Think through and check everything you loosened/tightened on the engine and check that. The plug wires are almost certainly on that list.
 
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Jesse said:
I have seen a problem before where the leads in the harness were the wrong lengths, so they were on the wrong plugs. The leads will all have a cylinder number as well as T or B. the engine has cylinder numbers at the base of the cylinders on the case. Make sure you have those right, because that could definitely cause the problem you are seeing. If it was run on a test stand, then it should be something simple. Think through and check everything you loosened/tightened on the engine and check that. The plug wires are almost certainly on that list.
Click to expand...

Aren't engines sometimes run on the test stand with "spare" factory mags, and then shipped with the new users mags in a seperate box?
 
I've never heard of that, but it could be. I'd feel conned by receiving an engine that had been run with other components used than the ones shipped with the engine. If you're going to test run my engine, it is for break in, timing, fuel tuning, etc.
 
Fred,

The engine came direct from Lycoming, it is past due to contact the them..

This engine should start with no issues right now without adding anything to augment the ignition system.
 
az_gila said:
Aren't engines sometimes run on the test stand with "spare" factory mags, and then shipped with the new users mags in a seperate box?
Click to expand...

Yep - I have a Lyc that I bought years ago and that's exactly what was done. Not only the mags, but the carb too. After they took it off the stand, they crated it up and threw in a box for the carb and the mags. (This was a Lyc overhaul.)

The engine I bought from Mattituck came "as run." I believe I did have to reinstall the carb.

Dan
 
ok here's update.
we installed the slick start. wow, you talk about sparks!!. but no start.
mags are timed perfect. start switch wired correctly. our last start attempt had puffs of smoke we never had before. and a back fire or two. spark plug wires connected to correct plugs. so we removed all 4 bottom plugs. disconnected starter. turned prop by hand until tdc #4. grounded all 4 plug wires and then turned master on and turned key to start. #1 sparked . conclusion, plug wires are marked wrong. will verify with lyc in the morning. my engine paperwork says engine ran for 59 min in test cell.
fred
 
Mag point opening (timing) can be correct, but for the wrong cylinder.

slickwireing002ya2.jpg
 
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So, either the harnesses are bad, or they're on the wrong side, or the mags are not right on the engine. You could pull the mags, set the engine to tdc on cyl 1, put the timing pin in the correct hole on the mag and reinstall, it could be that they had the engine on the wrong stroke when they inserted the mags, obviously not having run it that way, then shipped it. Personally, I'd read them the riot act and ask to be made right. Overall, if this fixes the problem, then you should be good. So, depending on the firing order, is it possible that the tdc mark for cyl #1 on the compression stroke could be cyl #4 on the exhaust stroke and vice versa? If so, that could easily explain the mistake. What is the firing order on that engine? If 1 & 4 are not next to each other, then that could well be the cause. I'd check the easiest things first, which would be the harnesses possibly on the wrong mags.
 
David-aviator said:
Fred,

The engine came direct from Lycoming, it is past due to contact the them..

This engine should start with no issues right now without adding anything to augment the ignition system.
Click to expand...

My IO540 came direct from Lycoming with retard mags, no impulse couplings, and no Slick start.

Ignition leads were attached to mags only, bundled and wrapped in plastic.

Walt's diagram shows firing order as 1-3-2-4, so 1 and 4 are not opposite each other.
 
A call to Lyc is definitely in order, but short of sending the engine back to them, you may be on your own to figure it out. You verified it's an ignition problem, so next you may want to do the same test for all 4 cylinders. If the firing order is correct, and they are just out or sequence, then the mag timing to the engine is the problem. Pull the mag, insert the pin (in the hole for the correct rotation), turn the engine to 25 btdc on cyl 1 and reinsert the mag. Also, you could look in the back of the engine to see if the timing mark on the gear shows correctly, although this doesn't matter much, but it can determine if the gear was installed correctly

Also, it may just be the one mag that is wrong. Maybe try grounding the mag that you know is wrong and disconnect the p-lead from the other mag and see if it will start, without the slick start. If it runs there, then only one mag is wrong.
 
mags are timed perfect
Click to expand...
Can you let us know "how" you timed them and with which marks?

NB Marks on the back of the flywheel tend to align with the crankcase split i.e. vertically up. Marks on the front of the flywheel with the starter i.e. about 5 o'clock as you look at the engine.
 
Andy Hill said:
Can you let us know "how" you timed them and with which marks?

NB Marks on the back of the flywheel tend to align with the crankcase split i.e. vertically up. Marks on the front of the flywheel with the starter i.e. about 5 o'clock as you look at the engine.
Click to expand...

they were mounted from factory. i call an AP friend of mine and he went over to it and check the timing for me. i wasnt there.
 
BobTurner said:
First, get another mechanic. Your engine is a certified type. And a brand new mag is less than half his estimate for an impulse coupler.
Check easy stuff first. Are the correct cylinders hooked to the correct high tension leads? Is the ignition switch wired correctly? (check with an ohmmeter that left mag P lead is open, right P lead is shorted, with key on start).
Then harder stuff, like mag timing.
Click to expand...

yep a brand new mag w/coupler is less than what my mechanic but he added in the possible core charges for a mag and a coupler. now i have no core mag so me giving him a brand new mag as core is like an additional $7-900 lost, then core for coupler is another chunk of change,,,,, he had all that in the new price because its the bottom line of what it is costing me for the coupled mag.
 
as of 10:30 am 2day I now have a strong running io360 thanks to Dave l. the mags were timed perfect but the internals were timed to a different cylinder. he took the mags apart and put them together the correct way, installed them, set them and said 100% guarantee it will start 1st time especially with that slick start u added. wow! it did!!!!!in the words of a famous rock and roll band "excuse me, while I kiss this guy", not really, he was old and ugly soo I just shook his hand!! he also showed me that there wasn't any sign of oil inside the mag, he said that proves these mags never ran on this engine. I called lyc they were very concerned that this happened. waiting for an answer. thanks to all who helped , this is a great community of people!!
fred
 
VETE76 said:
as of 10:30 am 2day I now have a strong running io360 thanks to Dave l. the mags were timed perfect but the internals were timed to a different cylinder. he took the mags apart and put them together the correct way, installed them, set them and said 100% guarantee it will start 1st time especially with that slick start u added. ..............fred
Click to expand...

I could be wrong, but the internal mag timing is setting the E-gap. Internal timing is for the mag only, and doesn't reference any cylinder. You time the mag to the engine after setting the internal E-gap, which is when you need to time the mags to TDC on Cyl #1, using the correct advance, usually around 25 degrees BTDC.

Are you saying that the leads weren't attached to the mags correctly, so that they went to the wrong cylinders? :confused:
 
it just like on a car engine the
'gear on mag and drive gear from engine must be mated exactly right. mine were 180 deg miss aligned
so when #1 was in position to fire the mag sent the spark to #4 intake stroke
 
VETE76 said:
it just like on a car engine the
'gear on mag and drive gear from engine must be mated exactly right. mine were 180 deg miss aligned
so when #1 was in position to fire the mag sent the spark to #4 intake stroke
Click to expand...

mmmm, read post #22 :D
 
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