AMT Olympus Thermocouple HELP!!!  
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AMT Olympus Thermocouple HELP!!! - 3/31/2006 11:26 PM   
Kevin Greene



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Status: offline 		I have a new AMT Olympus that is giving me problems....I have the Auto Start Unit and an AMT Eliminator. The engine is a few years old but new and never run...

When I initiate the start I get EGT errors---The EGT readout on my engine data terminal will go from air temperature to 1118 degrees when the start is initiated...The start is then aborted by the ECU and I get the EGT error beeps.

Here's the problem---When I remove the thermocouple from the engine the engine will initiate the start normally!!! When I touch the thermocouple to the engine (In a sense grounding it out to the engine) the start will immediately stop and give me the EGT error...It acts like a short circuit, touching the probe to the engine gives me the error--------

What gives??? I have tried two probes and get the same results.

Kevin

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RE: AMT Olympus Thermocouple HELP!!! - 4/1/2006 12:05 AM   
Kevin Greene



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Status: offline 		UPDATE----

I just went outside and rigged the engine for manual start. (Unpluged the Auto Start Unit from the ECU) I successfully started the engine manually with no problems. (Man--WHAT A BEAST!!!)

The only thing that I can figure out is that I'm getting some type of return voltage through the thermocouple with the ASU connected to the ECU...I even noticed a slight spark when I touched the thermocouple to the engine..

What should I look for???---The ASU unit worked perfectly with my AMT Mercury HP---

Kevin

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RE: AMT Olympus Thermocouple HELP!!! - 4/1/2006 12:14 AM   
Eddie Lozano



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Status: offline 		Kevin can you please PM me

Thanks,
EdLo

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RE: AMT Olympus Thermocouple HELP!!! - 4/1/2006 3:39 AM   
Kevin Greene



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Status: offline 		Eddie--I sent you a return PM....Silver Springs MD brings back a lot of memories while my father was stationed at the Pentagon in the late '60's---I attended Glen Haven Elemantary there and spent a lot of time exploring Sligo Creek...

Can ANYONE help me with my thermocouple problem????

Kevin

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RE: AMT Olympus Thermocouple HELP!!! - 4/1/2006 3:50 AM   
DThomson


 

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Status: offline 		Kevin, I would recommend you call Tom Cook. He knows alot about these engines. He may have a suggestion.

Dave

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RE: AMT Olympus Thermocouple HELP!!! - 4/1/2006 4:08 AM   
Kevin Greene



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Status: offline 		Thanks Dave...You're right---Tom Cook has a wealth of jet modeling info tucked away in that noggin of his!!! This has me stumped as I can't figure out electrically how this is happening. For starters, I'm going to start ohming out the umbilical leads--Perhaps a frayed wire might show up there.........Then I'll tear into the ASU....

Kevin

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RE: AMT Olympus Thermocouple HELP!!! - 4/1/2006 4:28 AM   
yeahbaby



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Status: online 		Kevin

give Benny a shout or John @ USAMT. perhaps they've experienced something similar and might have an answer.

got me stumped, but it's probably in the wiring of the ASU. nice piece of gear but I always preferred the manual start sequence.

L8R

buck


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RE: AMT Olympus Thermocouple HELP!!! - 4/1/2006 9:15 AM   
F-22-Raptor


 

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Status: offline 		Hi Kevin,

nothing to worry about. Just check the following! The end of the sensor does not have to be more than maximum 2mm inside the nozzle!! If this is the cause you will exaclty getting the error you have.

plus tha it should look like a "L"where the long part of the "L" should look to the end of the nozzle.

If you have the AMT Software, you will find a parameter to disable the sensor after startup. You should do this due to the fact that the older AMT engins will get pretty hot when going from idle to fuel power if you need to go around. This can happen when its hot outside. If the sensor is enabled this then can cause a shutdown due to high temperature.

I am sure if you give Bennie a call he will tell you exactly the same. I had the same circuumstances with my old Peggy ;-)
Andreas

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RE: AMT Olympus Thermocouple HELP!!! - 4/1/2006 12:18 PM   
Kevin Greene



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Status: offline 		It's not due to the sensor being too far inside of the nozzle---I'm aware of the false high temp readings if the probe is inserted too far in the nozzle. When executing my troubleshooting I completely removed the probe from the engine and initiated a startup with the ASU. I held the probe in my hand and placed the end of it in the heated exhaust stream at end of the nozzle to get the temp high enough to get the fuel pump to run when the temps and the RPM are up---But NOT touching the nozzle to the turbine. The engine commenced to start and IMMEDIATELY went into an error shutdown when I just touched the probe to the nozzle---As earlier stated, I witnessed a very faint spark when I touched the probe to the nozzle. I'll post pics later as I have to go to the office this AM..

Kevin

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RE: AMT Olympus Thermocouple HELP!!! - 4/1/2006 2:24 PM   
abqflyer



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Status: offline 		You've probably checked this, but if it is the Watlow thermocouple with the flat yellow connector, it can be plugged in backward. There are little "+" and "-" characters stamped on each half of the connector. They are really hard to see. If it is backward, it may be shorting to ground and causing it to read max temp. These connectors are huge and have no keying. Watlow claims that they have some special heat characteristics to keep the two leads at the same temp so as not to get erroneous readings, but I have my doubts.

Bob

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RE: AMT Olympus Thermocouple HELP!!! - 4/3/2006 3:29 AM   
Kevin Greene



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Status: offline 		Hey Bob!!

The yellow connector I have on both thermocouples is keyed---One flat pin is wider than the other. I'm sure I have plugged in the thermocouples with the correct polarity.

It's really no big deal that the Olympus won't start using the ASU as I've easily started the beast manually several times now.. However, when the ECU starts to feed in the fuel I'm getting a lot of flames. Since I have no control over how much fuel is dumped into the engine at startup I guess this is normal with this large engine. I'm keeping the air on until the engine stabilizes...I suppose that after the fuel pump breaks in the starts will become smoother. I've already noticed that the max pump voltage has come down some when the engine is at full throttle which is indicative of the pump becoming more free.

Kevin

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RE: AMT Olympus Thermocouple HELP!!! - 4/3/2006 4:27 AM   
Bandito


 

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Status: offline 		kevin, You need to talk to Eddie Weeks or Bennie or Tom Cook about this problem. # 1 thing is that a AMT fuel pump does not have to BREAK IN... The tolorance's are precise. This is not the problem. If you want to prove it to yourself, put another pump on it. I am not saying the pump is not bad, I am saying it does not have to break in........The yellow connector on the sensor probe has a pos and a neg side. So does the other end . You might make sure they are plus to plus by using a voldmeter. Only a very few times have I seen this to be backwards but it has happened. Wish I could could be more help but thats what the manufactuer is supposed to be able to help with. Is this a USA or a NL product????? Good luck, Ray Blair-X AMT USA Rep, current JetCat USA dealer.

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RE: AMT Olympus Thermocouple HELP!!! - 4/3/2006 5:24 AM   
abqflyer



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Status: offline 		Too bad it wasn't as simple as a reversed connector. There are parameters for the startup speed. If it's getting lots of flame you may be able to turn it down a notch. Last year we were playing with some of the parameters on one of my engines. Rodney said it would probably throw some flame on startup. He asked if I'd mind that. I told him, "Heck no. Airshows pay double for extra fire"

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RE: AMT Olympus Thermocouple HELP!!! - 4/3/2006 12:58 PM   
Doctor J.



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Status: offline 		Kevin,
It does in fact sound like you may have a reverse polarity problem. From reading your post it does not seem to be on the thermocouple end. It's more than likley on the ECU side. If you were to remove half of the yellow connector on the ECU side by unscrewing it with a flathead screwdriver you will observe a green and a white wire connected. Make sure that the white wire is on the negative side and the green wire is on the positive side. If you continue to have problems give me or Rodney a call.

John Ligons
AMT-USA

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RE: AMT Olympus Thermocouple HELP!!! - 4/3/2006 3:38 PM   
abqflyer



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Status: offline 		Is it possible that the thermocouple wires were somehow hooked up backward in the yellow connector? I think they are color coded also, but I can't remember how (black stripe, red stripe on one wire i think). Probably wouldn't hurt anything to switch them and test.

Bob

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RE: AMT Olympus Thermocouple HELP!!! - 4/3/2006 4:11 PM   
DocYates



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Status: offline 		Had a similar probelm with a T-750, when I reversed the plug on the temp probe. Interesting though that Kevin's "shorts out", that really sounds more like an electrical short or voltage problem. If the probe was hooked up wrong, then it should not work when he puts it in the tail stream, am I wrong in that assumption???
Tommy

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RE: AMT Olympus Thermocouple HELP!!! - 4/3/2006 10:38 PM   
Kevin Greene



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quote:

ORIGINAL: DocYates

If the probe was hooked up wrong, then it should not work when he puts it in the tail stream, am I wrong in that assumption???
Tommy


I can also start the engine manually with the probe inserted properly---You would think that if the polarity was reversed the engine would not start regardless if the start was accomplished manually or with the ASU.

I'm going out right now to check the polarity on the ECU.

Kevin

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RE: AMT Olympus Thermocouple HELP!!! - 4/3/2006 10:45 PM   
Kevin Greene



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Status: offline 		The EGT wires are properly connected to their respective terminals...White to negative and green to positive....I'm going to open up the ECU to see if any of the wires are not in their proper places--Like reversed polarity inside of the ECU. I'm going to compare it to my Mercury's ECU...

Kevin

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RE: AMT Olympus Thermocouple HELP!!! - 4/3/2006 11:14 PM   
Kevin Greene



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Status: offline 		OK---Here's what I found...Look at the pic----------The ECU on the right is the Mercury ECU. The ECU on the left is the Olympus ECU.

Note that the wires for the thermocouple are soldered in differing places on the PC boards---The Mercury has the thermocouple wires soldered in the outer most locations, while the thermocouple wires in the Olympus ECU are soldered in the inner most locations....Does this matter??? (Are these electrically the same???) Unless someone can give me a definitive answer I don't want to swap the positions of the wires in the Olympus ECU....

Kevin

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RE: AMT Olympus Thermocouple HELP!!! - 4/4/2006 12:47 AM   
Kevin Greene



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Status: offline 		Looks as though it doesn't matter if the thermocouple leads are in the inner or outer locations as they both appear to be electrically identical as shown in this pic I just took...

Kevin

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RE: AMT Olympus Thermocouple HELP!!! - 4/4/2006 4:22 AM   
G4guy


 

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Status: offline 		Did you actually call Rodney or anyone else at AMT? They always have helped me, everytime.

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RE: AMT Olympus Thermocouple HELP!!! - 4/5/2006 6:33 PM   
Doctor J.



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Status: offline 		Kevin,
Send your ECU in to us and I will get it sorted out for you. I should be able to ship it back to you the same day.

John Ligons
AMT-USA

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RE: AMT Olympus Thermocouple HELP!!! - 4/5/2006 11:44 PM   
Kevin Greene



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quote:

ORIGINAL: G4guy

Did you actually call Rodney or anyone else at AMT? They always have helped me, everytime.


Yes I did---I called after hours and left a message. I didn't recieve a return call at home but a reply from John here on RCU...Which is just as good!!!

John---I'm going to start my AMT Mercury one more time to see if it is the ECU or the ASU....I haven't started the Merc in a few months and just want to be sure I narrow it down to the right assembly. Since I've removed the Merc from the plane it was in I'll have to make a test stand. It will be a few days before I can do so...

THANKS!! Kevin

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RE: AMT Olympus Thermocouple HELP!!! - 4/6/2006 4:04 PM   
Doctor J.



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Status: offline 		Kevin,
Give me a call when you finish. I will be in Toledo the rest of the week but you can reach me on my cell phone (310) 213-5403 or email me at jligons@usamt.com.
We will get you sorted out.

John Ligons
AMT-USA

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