Partial Engine Failure on Takeoff

[Brian Scranton]

I bet that got your intention. It certainly got mine. 

The backstory: cylinders 2 and 3 have consistently been the hottest in the 30 hours I have owned this plane (since late Feb). #2 would lean first, then #3, followed by #1 and #4. So, I swapped injectors (1 and 3, 2 and 4)...also, this is an IO-360a1a with a RayJay (which has a little air collar that goes on top of the injection). Flew it for 1.5 hours the other day and noticed how nicely balanced by CHTs were. Finally.

Went to fly today. Took off, WOT and 28.5MP with the turbo engaged. Made my turn and was abeam the airport when I noticed (at around 800 feet) that my #3 EGT was spiking off the chart. Panic. Then #3 simply quit. Then #1 quit. Turned back to the airport, GUMPS, traffic announcing he's taking 31 as I turn final for 13, "negative, short final 13" and he holds...I land, with a turd in my pants and my heart in my throat.

I go do a few run ups (I have my buddy, a CFII and A&P with me) and all cylinders are working at 2000rpm (no turbo), lean and rich. Run up to 2300rpm, lean it out for best power and #3 begins to get hot. I push the mixture forward and #3 continues to rise while others are coming back down. I check mags to see if I have a cracked plug--negative. So, for some reason #3 isn't getting much fuel (clearly lean) even with mixture at full. 

I pull the cowl. Check all the hoses. Inspect the air collars, look for fuel leaks. I turn on the boost pump to see if fuel is leaking as well as my buddy looks at the injectors. Nothing! 

When the injectors were removed a few days ago, I noticed how #1 had a cup shaped opening where it linked with the fuel line, while #3 was more cylindrical in shape. Showed it to my A&P who said, "meh, no big deal." But that's the only thing I can think of that was different. And still, she flew fine for 1.5 hours without incident! Maybe the air collar wasn't aligned with the air intake on the injector? Maybe something shifted? Loosened up? I dunno--I checked the fuel lines, checked the hoses again, tightened everything and she still was getting hot on #3. So, I just pulled everything and swapped the 2 injectors back. Did a few long runway rolls...full power, full turbo and everything seems fine now, though I have not flown it--It got too windy. 

Jeesh. Way to "inject" a little excitement into my day. 

 

[Piloto]

Check the exhaust muffler for possible blockage. As the internal exhaust pipes ages they can become loose blocking the exhaust. This also causes high EGT readings.

José 

[Brian Scranton]

I'll take a look! Pretty sure it was the swapping of the injectors though! I'm going to fly today and will report back. 

[carqwik]

A partially clogged injector will cause high EGT on takeoff but not show up on a low power run up...at least that was my experience.  Took off after an A-OK run up and the EGT on one cylinder went sky high...reduced power...landed.  Found a very small piece of something in the injector....almost smaller than a grain of sand.  

That was all it took....next takeoff...no problems. 

[Brandontwalker]

A partially clogged injector will cause high EGT on takeoff but not show up on a low power run up...at least that was my experience.  Took off after an A-OK run up and the EGT on one cylinder went sky high...reduced power...landed.  Found a very small piece of something in the injector....almost smaller than a grain of sand.  

That was all it took....next takeoff...no problems. 

Same experience here.

[Brian Scranton]

Ok, good to know guys--thanks! Weird that the cylinder quit though...and then cylinder 1 went right after. I checked the injectors and they seemed clean/clear. 

[takair]

When you say the both "quit", can you describe the symptoms? Did EGT and CHT go toward ambient?  Was it running rough and then really rough with almost no power?  

[Brian Scranton]

Over the course of about 10 seconds, the #3 Cyl had all its bars lit up, then no EGT reading at all...then the same thing happened on #1. There was still a CHT indication (I think--it all happened every fast and was way more interested in getting on the ground then starring at the monitor). Definitely really rough when they quit...but, I was luckily in position to quickly get downwind for the approach, so I closed the waste gate, pulled the throttle to 17'' and hurried down. 

 

[kortopates]

Your unit doesn't record data?

[Brian Scranton]

It does, but you need a computer from 1994 to download it. I could probably find it on eBay but the Insight software (GEMCOM.EXE) is nowhere to be found on the internet.

Edited May 23, 2016 by Brian Scranton

[carusoam]

Brian,

See if this sounds similar...

I felt that way about my BK GPS....  To communicate with the device required a RS232 socket.  Aka 1995 computer...

realistically I needed a 1995 to 2015 converter.  The device is essentially USB on one end and a RS232 plug on the other.  Comes with a disk full of drivers.  The JPI has it's own plug to go from RS232 to what looks like a earphone jack.

Works like magic downloading data off my JPI...

Still needs some help uploading info to my GPS.

 

Let me know if you need details for this device.  Approx  $20 at Walmart.com? (Old fuzzy memory)

Best regards,

-a-

[carqwik]

Barring physical damage or breakage to engine cylinder components (like pushrods, rocker arms, springs, valves, etc.), there are only three other places to look: fuel, air, and spark...  My totally uninformed WAG is that you've got some kind of fuel delivery problem.

[takair]

Excuse my ignorance, but is it normal to use the TM at takeoff?  Do you still introduce full throttle?  

[Brian Scranton]

It is...elevation on the field is 5759' and DA yesterday for example was 7900'. Makes a big difference to engage that turbo on the roll. 

[1964-M20E]

How was the engine running?  rough making power smooth???

 

Could it be a sensor probe or wiring issue since you say #3 and #1 quit rather quickly and there was not indication?

 

 

[gsengle]

Ask what two cylinders have in common... Exhaust?

Sent from my iPhone using Tapatalk

[Brian Scranton]

All possible--but I didn't screw with anything but the injectors. So the EGT probes never got touched...I really think something screwy happened when I swapped the injectors--they looked different and I think, for some reason, the look made the difference. There was no perceptible obstruction in them, no observed fuel leak, air collar hoses were all tight. Sooooo strange...but, I'll fly this morning (couldn't yesterday due to winds) and see if I am right...I swapped them back to there original spots and hopefully, that at least solves the immediate problem. The whole purpose in switching them was to get more fuel to #3 and less to #1 to balance the CHTs. 

[Guest]

There are only a few variations in fuel injectors whether turbocharged or normally aspirated.  Original designs were of one piece construction later ones have a removable stainless steel insert.  I'm intrigued by your description of the nozzles in the original post.  I have seen them assembled with the stainless insert left out.

Clarence

[chrisk]

14 hours ago, carusoam said:

Brian,

See if this sounds similar...

I felt that way about my BK GPS....  To communicate with the device required a RS232 socket.  Aka 1995 computer...

realistically I needed a 1995 to 2015 converter.  The device is essentially USB on one end and a RS232 plug on the other.  Comes with a disk full of drivers.  The JPI has it's own plug to go from RS232 to what looks like a earphone jack.

Works like magic downloading data off my JPI...

Still needs some help uploading info to my GPS.

 

Let me know if you need details for this device.  Approx  $20 at Walmart.com? (Old fuzzy memory)

Best regards,

-a-

Yes, something like this.  http://www.amazon.com/TRENDnet-TU-S9-USB-Serial-Converter/dp/B0007T27H8?ie=UTF8&psc=1&redirect=true&ref_=oh_aui_search_detailpage

It works well with my JPI, but as mentioned above, it requires the RS232 to "earphone jack" from JPI.   

[mooniac15u]

15 hours ago, Brian Scranton said:

It does, but you need a computer from 1994 to download it. I could probably find it on eBay but the Insight software (GEMCOM.EXE) is nowhere to be found on the internet.

The software you need is available on the Insight Tech Support page: http://www.insightavionics.com/support.htm

About 3/4 of the way down the page on the far left is a section labeled "Old GEM Series."  There is a link to download a ZIP file that contains the GEMCOM.EXE file.

[Brian Scranton]

Clarence--one had the stainless insert and the other didn't! Weird.

Anyway, I just flew and all was good. No spike. No problems. Flew for 45 mins then went to the shop. Pulled the cowl, checked everything again, had my A&P inspect, then observe the seals around the air collar as I ran the engine up and didn't notice a thing. So...I guess I won't be swapping 1 and 3 again. Here's a photo from just after takeoff today.    

[geoffb]

Why are the injectors not all the same?  I don't know anything about the turbo installation.  But you can bet I'd be digging into the STC documentation to see what I'm supposed to have in there, then comparing what's really in there to what's supposed to be in there.  Did you ever flow check the injectors?  I'd be curious to see my flow distribution between cylinders and would have checked that before I started swapping parts.

[bradp]

3 hours ago, Brian Scranton said:

Clarence--one had the stainless insert and the other didn't! Weird.

That's very odd.   Did you happen to take any photos of the differences between injectors?

[Guest]

50 minutes ago, bradp said:

That's very odd.   Did you happen to take any photos of the differences between injectors?

The ones with the stainless insert is current production, older ones are one piece with no insert. Both can be used in the same engine.

My guess is that the missing insert was lost during cleaning, likely in the bottom of the cleaning solution.  The engine will have had a very rich mixture on one cylinder and likely lean on the others.

Clarence

[takair]

I think Clarence is on to it.  I think the insert really sets the flow.  I think it's worth a follow-up.