Continental Engine Problems During Climb Out

TylerC

TylerC

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TylerC
Hello everyone, I’m new to this site and new as a pilot. Recently I’ve been having problems that I’m hoping to get some answers on, or at least get some direction for maintenance moving forward. I know there’s guys on PoA that have a lot more experience than I do and I’m hoping to draw upon that experience. So here’s what’s going on, I have a 1970 Bellanca Super Viking with a Continental IO-520K and while doing a run up on the ground everything goes fine. I lean for best power because the elevation at my home airport is 4200ft, mags drop around 200RPM’s but both L and R are close during the check, I don’t have to wait along time to takeoff because it’s an uncontrolled field with limited traffic, again everything goes well while on the ground. The problem begins shortly after rotation, the engine begins to sputter while climbing out at full power. And what I’ve noticed is that the fuel flow gauge will drop slightly with corresponding engine sputter, and this continues until I level off from the climb and reduce MP and RPM’s. While leveled off the issues disappear and the plane runs fine. Also, no issues on decent and landing. The only time I have issues is during the climb out. So I’m wondering if anybody knows what is causing these issues? I’ve been told many things but there’s no definitive answer or consensus on what it could be. I’m hoping someone on this site has experienced this problem before and has found the solution to suit. Any help would be gratefully appreciated! Thank you in advance. Tyler
 
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My bet is you are sucking air through a small leak in the suction side of fuel system.
 
I know nothing about this but have you tried taking off full rich, and is the fuel pump on during takeoff?

I’ve seen leaning operations are typically recommended >5000’ and <75% power (vs full power for takeoff)
 
My guess your running lean. Lovely airplane. Mine was the Lyc with RayJay's. But that was a many years ago. I have some time in the Cont powered ones as well, but agian many years ago. Whats the fuel flow look like on climb. Richen up a bit and I think you'll cure your problem. When was the last time you fuel injection was set up? It's a good system, but pressures should be checked once in a while.
 
Might be lean enough to be causing detonation.

Missing after rotation, and fuel flow gauge dropping as well, implies a weak fuel pump. In the climb attitude the fuel has a larger distance to climb to the engine than it does on the ground, and a weak pump might be right on that margin. Or there's a restriction in the aft tank outlets. If so, running richer would actually make it worse.

All guessing.
 
So just to give a little more insight into the issue I have tried running full rich on takeoff before to try and fix the problem but it doesn’t solve the issue. I’ve also taken it into the shop where they’ve adjusted the fuel mixture and idle. On takeoff the POH doesn’t call for the boast pump to be turned on so all the fuel coming into the engine is fed by the the mechanical fuel pump. Another think that the POH states is to only use the main tanks on takeoff so I’ve tried both the left and right main to see if that made a difference but the problem continues on both main tanks. I really appreciate the insight and different ideas, hope to keep them coming and find a solution. Thank you!
 
My IO-550 did something similar. I had an IRAN done on the throttle body and the fuel distribution manifold overhauled. They said there seemed to be a leak from one of the orings on the throttle body, not sure if that was the cause, but the issue went away.
 
Dan Thomas said:
Might be lean enough to be causing detonation.

Missing after rotation, and fuel flow gauge dropping as well, implies a weak fuel pump. In the climb attitude the fuel has a larger distance to climb to the engine than it does on the ground, and a weak pump might be right on that margin. Or there's a restriction in the aft tank outlets. If so, running richer would actually make it worse.

All guessing.
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A bad mechanical fuel pump is one of the ideas I’ve been tossing around as the possible issue. Another thing I’ve considered is it might be a filter of some sort that is blocked and not allowing enough fuel or air into the engine under full power. One of the thoughts I’ve had was to take the Bellanca up to a safe altitude and leave the plane under full power as I level out so I can see if the problem persists without reducing MP & RPM’s. My only concern is I don’t want to lose the engine altogether. A pilot friend of mine also suggested I turn on the electric fuel pump on takeoff to see what happens but I’m hesitant to do that because I don’t want to flood the engine. I know this is a lot of information but again just looking for solutions.
 
Grum.Man said:
My IO-550 did something similar. I had an IRAN done on the throttle body and the fuel distribution manifold overhauled. They said there seemed to be a leak from one of the orings on the throttle body, not sure if that was the cause, but the issue went away.
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So that’s great news! And just to clarify this only happened to you while climbing out? And apologies but what’s an IRAN?
 
TylerC said:
Hello everyone, I’m new to this site and new as a pilot. Recently I’ve been having problems that I’m hoping to get some answers on, or at least get some direction for maintenance moving forward. I know there’s guys on PoA that have a lot more experience than I do and I’m hoping to draw upon that experience. So here’s what’s going on, I have a 1970 Bellanca Super Viking with a Continental IO-520K and while doing a run up on the ground everything goes fine. I lean for best power because the elevation at my home airport is 4200ft, mags drop around 200RPM’s but both L and R are close during the check, I don’t have to wait along time to takeoff because it’s an uncontrolled field with limited traffic, again everything goes well while on the ground. The problem begins shortly after rotation, the engine begins to sputter while climbing out at full power. And what I’ve noticed is that the fuel flow gauge will drop slightly with corresponding engine sputter, and this continues until I level off from the climb and reduce MP and RPM’s. While leveled off the issues disappear and the plane runs fine. Also, no issues on decent and landing. The only time I have issues is during the climb out. So I’m wondering if anybody knows what is causing these issues? I’ve been told many things but there’s no definitive answer or consensus on what it could be. I’m hoping someone on this site has experienced this problem before and has found the solution to suit. Any help would be gratefully appreciated! Thank you in advance. Tyler
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Read about something similar on an O300, after throwing thousands of $$$$ at it in parts, inatake reseal, new mags, new harness, new plugs, new carburetor, they found a valve spring did not meet book specs, replaced the valve springs and all was well. Have no idea if thats your problem but something to keep in mind.

In theory you could identify which cylinder(s) are missing if you had an engine monitor by identifying falling EGTs.
 
TylerC said:
So that’s great news! And just to clarify this only happened to you while climbing out? And apologies but what’s an IRAN?
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Yes, when climbing at a high rate it would sometimes stumble then come back to life. IRAN is inspect and replace as necessary. Basically they just replaced all the o-rings and gaskets, the engine was low time by old so no need to replace any bushings or throttle shaft.
 
It only during very high power settings.
This is the highest fuel flow the engine will be using. (it does sound like a fuel problem)
But (it sounds like) we don't know the actual gph because there is no fuel flowmeter.
That engine needs to have available 28-30gph on takeoff/climbout. (this is higher than the CAT M-0 spec but it is widely accepted as necessary, the CAT specs are too low).
So I would definitely be doing the fuel flow/pressure set up as specified in M-0. (ESPECIALLY after hearing that the mechanic tweaked the idle and mixture - you can't just do that, you must complete the full procedure as one setting affects the other, you have to follow the step by step process).
Yes I agree with the other suggestions of a fuel line admitting air, or an ineffective fuel pump, and I bought a Viking in which the tank vent had been plugged long before I owned it, and it sucked that tank into a very deformed shape before it was unplugged.

PS On another chat group there was a gent who repeatedly flew an airplane which had similar symptoms; engine trying to die on climb out. So I think the same advice he received applies here; please get this fixed on the ground, don't continue to tempt fate. :)
Hope you enjoy the Viking, I just sold my 1967 after 20 years of happy ownership.

M-0 is available on CSOB (cheapsonofabeech), Mike Caban. He posted the copy I have.
 
There are 2 aircraft I’ve encountered with a similar issue but a little worse.
Ironically; both at the same airport. Run-up on ground was fine as it was in level flight. However; when the fuel pump was raised above the fuel source (as in nose-up) the pump would then suck air though a loose suction fitting. The first case was
discovered by the NTSB. Second pilot had more luck and only needed to repair the aircraft.
 
Sounds like a fuel leak...sucking in air. Have someone look at your fuel lines while you run the electric pump to pressurize the lines...be ready to shut off quickly if it's leaking.
 
One thing to keep in mind: Electrical issues represent about 90% of engine problems. In this case, it's the ignition. Magnetos are notoriously unreliable, which is primarily why we have two of them, and they are really old technology that demands constant care and attention. Bendix has a 400hour recommended internal inspection, Slick's is 500 hours. Yet it seems that most magnetos are being run to failure. The spark gets weak, and a weak spark shows up soonest with a lean mixture. A spark isn't just a spark; in those cylinder pressures you need a good hot spark, and at best, magnetos don't deliver the same spark energy your economy car has. They need looking after.

Sparkplugs and plug harnesses also need checking. Sparkplugs need to be spark-tested at pressures up to 135 PSI. That takes the right machine, and some shops don't have it. And the machine needs calibrating. There are instructions for that.

The old Champion plugs are horrible. Their newer plugs are better, but I bet there are still older plugs in stock in some places. Champ should have recalled them. Tempest is a better bet. Sparkplugs get awfully hot, and they can suffer internal failure at those temperatures and arc internally, failing the spark at the business end. Harnesses can do it, too.

So. How long since the mags were off and inspected? Who did them? Did they get the E-gap right? How old are those plugs? Does your mechanic have the proper equipment to test the plugs and harness?

All of this is worth checking even if it turns out to be a fuel problem.
 
When was the last time you had the control unit calibrated?
 
Surprised we have made it this many posts without someone mentioning that this is were engine monitors start paying for themselves. (Maybe I missed that post)
Have flown two planes this year that just by looking at the EGT during the runup I knew I had a plugged injector. Without the engine monitor I would have never known there was an issue. At Takeoff power essentially one injector was causing a cylinder to run lean of peak. I doubt this is the OP's issue. But an engine monitor would give a much better idea what is happening and to which or all cylinders.

How long after takeoff do you notice the issues?
Have you tried a full power runup on the ground?
Have you tried a runup after landing?
You have already had a mechanic look at, Obviously it would be much easier and safer to be able reproduce and diagnose on the ground, but that isn't always feasable for some issues.

if an engine sputtered on me on climb out, I would pretty much be full Rich and Fuel Pump on almost immediately unless I had some information to indicate that is a bad idea. If concerned about flooding the engine. Try it in a safe environment. So far I have never encountered an engine that would die by going full power and full rich and pumps on, they can run a bit poorly, but they do run. Until sorted out I would not be out of range of a runway any longer than absolutely necessary.
Might be worth getting an instructor or experienced pilot to help you test and diagnoise. They may recognize what is going on, or if you do have an emergency you will have someone to help you deal with it.

Brian
CFIIG/ASEL
 
Dan....he says the fuel flow drops during this event.

A friend of mine, with a Bonanza E series engine (pressure carb), had similar issues....but not during takeoff. His was during cruise and leaning. What we discovered is that when he applied fuel pressure with the wobble pump (similar to aux electric pump) I observed fuel gushing out of a spot in the fuel hose prior to the fuel pump. There was a spot in the hose that was rubbed thru into the braids.... Engine was not running. Both of us were astonished that the engine would even run and there were no visible signs of a leak....until he began pumping.
 
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Clip4 said:
When was the last time you had the control unit calibrated?
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I’m not sure, I’m out of town and don’t have the log books with me. I’ll look into it when I get home.
 
brcase said:
Surprised we have made it this many posts without someone mentioning that this is were engine monitors start paying for themselves. (Maybe I missed that post)
Have flown two planes this year that just by looking at the EGT during the runup I knew I had a plugged injector. Without the engine monitor I would have never known there was an issue. At Takeoff power essentially one injector was causing a cylinder to run lean of peak. I doubt this is the OP's issue. But an engine monitor would give a much better idea what is happening and to which or all cylinders.

How long after takeoff do you notice the issues?
Have you tried a full power runup on the ground?
Have you tried a runup after landing?
You have already had a mechanic look at, Obviously it would be much easier and safer to be able reproduce and diagnose on the ground, but that isn't always feasable for some issues.

if an engine sputtered on me on climb out, I would pretty much be full Rich and Fuel Pump on almost immediately unless I had some information to indicate that is a bad idea. If concerned about flooding the engine. Try it in a safe environment. So far I have never encountered an engine that would die by going full power and full rich and pumps on, they can run a bit poorly, but they do run. Until sorted out I would not be out of range of a runway any longer than absolutely necessary.
Might be worth getting an instructor or experienced pilot to help you test and diagnoise. They may recognize what is going on, or if you do have an emergency you will have someone to help you deal with it.

Brian
CFIIG/ASEL
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I agree an engine monitor would be a great thing to have right now but unfortunately I don’t have one on this plane. As far as your questions go, I notice the problems about 150ft AGL, I have tried full power run up on the ground and I don’t notice any problems, I’ve also did the run up after landing and again no problems. I’ve had three mechanics look at it on the ground with no problems identified. I’ve gone up with a CFI with 15000 hours and he’s noticed the problems and suggested we turn back to the airport immediately, which we did.
 
Checkout_my_Six said:
Dan....he says the fuel flow drops during this event.
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A smoking gun, for sure. Bad pump? Sticking check valves in the pump? Sucking air somewhere, maybe.

Perhaps they need to block it up in the climb attitude and try it at full power. Pretty hard to find and fix something that won't stay broken.
 
Others have mentioned likely causes. All to often on older aircraft basic maintenance goes by the wayside. How long since the mags were overhauled, ignition harness replaced, and fuel and other hoses replaced? If it’s past 5 years probably time to make a investment.
 
Is a 200 rpm mag drop normal for this engine?
 
My thought is the leak is in the suction part of system. How could you pressurize to leak check? That would work if the pump were in the tank.

If the condition occurs on either tank it’s likely a issue from the Selector to the Pump. Perhaps plumbing in a test section to pressurize with air and check with soap n water?

I have found some Cherokees with tiny fuel stains under the Left side panel.
There was no apparent reason such as screw marks. I have wondered if the tubing could have some porous areas. When tubing was replaced the pilot said fuel pressures no longer fluctuate.

I’ll guess that air was sucked in and fuel would weep through with the engine stopped.
 
TylerC said:
I agree an engine monitor would be a great thing to have right now but unfortunately I don’t have one on this plane. As far as your questions go, I notice the problems about 150ft AGL, I have tried full power run up on the ground and I don’t notice any problems, I’ve also did the run up after landing and again no problems. I’ve had three mechanics look at it on the ground with no problems identified. I’ve gone up with a CFI with 15000 hours and he’s noticed the problems and suggested we turn back to the airport immediately, which we did.
Click to expand...

With it occurring at about 150ft, How long of a full power runup have you done?
Guessing it takes you somewhere around 1 minute or a bit more so to get to that altitude. So I would make sure I was doing at least a 2 minute full power ground run trying to reproduce.

Looking forward to finding out what you find the ultimate answer is.

Brian
 
brcase said:
With it occurring at about 150ft, How long of a full power runup have you done?
Guessing it takes you somewhere around 1 minute or a bit more so to get to that altitude. So I would make sure I was doing at least a 2 minute full power ground run trying to reproduce.

Looking forward to finding out what you find the ultimate answer is.

Brian
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That’s actually a really good idea. I’ll try that out and see what comes of it. Thank you.
 
TylerC said:
One of the thoughts I’ve had was to take the Bellanca up to a safe altitude and leave the plane under full power as I level out so I can see if the problem persists without reducing MP & RPM’s. My only concern is I don’t want to lose the engine altogether.
Click to expand...

I think this would be a good test. I don't see how leveling off would add any more risk to the situation than you are already assuming. Just circle over the airport.

C.
 
Tyler, welcome to our community of Bellanca Viking owners! There is some great advice in the various posts in this thread. My belief is that you do indeed have a fuel problem. In fact I had virtually the same problem with a Bellanca aircraft that I purchased a few years ago. I took no chances and overhauled the entire fuel and intake system: fuel pump, throttle body, fuel control, gascolator, fuel selector switch - everything. Problem solved along with the benefit of a good dose of peace of mind. As someone mentioned above, 50 year old airplanes very likely have many systems in need of maintenance. Fuel and ignition systems deserve the very best care possible and the cumulative cost is not that much. If you are not all that familiar with the special maintenance needs of a Viking I would encourage you to contact me - I would be pleased to help you.

Rob
Bellanca Aircraft, Inc.
 
Perhaps combine Dan and Brian’s ideas?

Deflate main struts and inflate nose strut to maximum for extended run?

Maybe a block too?

Losing power in climb attitude sucks!
 
The big problem with an extended ground run will be keeping those cylinder temps within limits.
 
The 1970 Viking employs vented fuel caps for the main wing tanks and a non-vented cap for the aux tank in the fuselage, which has a venting tube exiting through the belly.
 
Robert W said:
CONTINENTAL MOTORS
SERVICE INFORMATION DIRECTIVE
SID97-3G
Click to expand...

It’s now Continental Aircraft Engine Maintenance Manual M-0, which I mentioned earlier.
Let me find the link I referred to…

this is a pretty recent version, keep in mind corrections/additions happen regularly with this document.

direct (large) pdf download; go to 6-4.7.1
(it starts on pdf page 111, document-designated page 6-15, and goes on for 15 pages from there)

https://www.csobeech.com/files/TCM-StandardPracticeMaintenanceManual.pdf
 
Robert W said:
When was the last time the fuel pressure Was checked on that engine?[/
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Rob58 said:
Tyler, welcome to our community of Bellanca Viking owners! There is some great advice in the various posts in this thread. My belief is that you do indeed have a fuel problem. In fact I had virtually the same problem with a Bellanca aircraft that I purchased a few years ago. I took no chances and overhauled the entire fuel and intake system: fuel pump, throttle body, fuel control, gascolator, fuel selector switch - everything. Problem solved along with the benefit of a good dose of peace of mind. As someone mentioned above, 50 year old airplanes very likely have many systems in need of maintenance. Fuel and ignition systems deserve the very best care possible and the cumulative cost is not that much. If you are not all that familiar with the special maintenance needs of a Viking I would encourage you to contact me - I would be pleased to help you.

Rob
Bellanca Aircraft, Inc.
Click to expand...
Hey Rob I sent you a PM. Looking forward to hearing from you. Thanks!
 
I think I want to start with the
CONTINENTAL MOTORS
SERVICE INFORMATION DIRECTIVE
SID97-3G and having this service performed on my aircraft, the question is are there any recommended maintenance companies close to the Clovis, NM area who are familiar with this process? I don’t want to use a company whose unfamiliar with this directive or who doesn’t have the tools to complete the job. Again any recommendations would be greatly appreciated!
 
The procedure has been around a while. Finding gauges and a Tech shouldn’t be that difficult.
 
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