JPI 900 Manifold Pressure Problem

[larryb]

I have a theory that a snubber is a better fix because it will keep the guts of the transducer from vibrating and wearing. I think the transducer will last longer with the snubber, regardless of the firmware fix.

[N601RX]

The restrictors settled my FP and MP down.  I posted plots of before and after several post ago.  They should also provide some level of safety if there is ever a leak.  If I have to have a leak of fuel or oil I would much rather it be from a .010" hole vs an open 1/4"line.  

[Marauder]

On 7/28/2015 at 8:59 PM, Marauder said: My wife is in love with zucchini. I'm sure it is a size thing, but she can't get enough of it. She keeps going out to the garden and checking to see if they are big enough

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I'm reviving this fun thread   - I've had my JPI900 about 5 months, and I like it on the whole.   But I have one major beef with it.   My MP bounces by about 0.5" constantly- no big deal, just an annoying distraction in my visual field.  JPI supposedly gave my dealer the firmware fix, but it made no difference at all.  Grrr.   It's particularly annoying because there's no numbers on the analog arc, so no way to set by roughly eyeballing it - the single worst part of the design.  

I'm wishing I kept my analog MP/RPM gauges - particularly since the JPI partially crashed once in flight before the firmware upgrade (lost all engine readings but kept fuel level and a couple other things) - it rebooted after about 30 seconds, just as I was about to pull the breaker to reset.  No way I'm sending back to JPI currently unless it recurs - this would ground me as it's primary.

Should I install a "snubber"?   Should I quit bitching because 0.5" of oscillation is normal?   Should I make some zucchini instead?  Maybe this would mellow me out.

Dev -- mine is still fluctuating 0.1 psi. It might be a rounding issue because sometimes it remains constant.

Does your unit look like the new firmware version (2nd photo I posted)? If so, I doubt the firmware being updated will help.

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[DXB]

1 hour ago, Marauder said:

Dev -- mine is still fluctuating 0.1 psi. It might be a rounding issue because sometimes it remains constant.

Does your unit look like the new firmware version (2nd photo I posted)? If so, I doubt the firmware being updated will help.

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Yeah it looked like the second version even at initial install.  Mine bounces more than 0.1.

[DXB]

Reviving this thread...for the second time.   Brief recap- the firmware fix for the EDM-900's MP constantly fluctuating by around +/- 0.5 didn't work.  So I called JPI to send me a snubber.   They sent me one, but it doesn't match the fitting on their MP transducer.   It also doesn't have any markings on it to help me discern the size. Per my avionics guy, it appears to be a 3AN fitting, and I might need a 4AN fitting, but he doesn't have one on hand.  My ability to figure this stuff out on my own is nonexistent.

So i call JPI tech support again. The guy tells me there isn't a snubber that fits their transducer, and I have to find an adapter.  Why didn't they tell me this in the first place rather than just send me something that doesn't fit?  I ask what adapter do I need and where can I get one.  The guy gets in a huff even though I've been polite the whole time.  He says he doesn't know and will back to me....I'm still waiting.

Has anyone here who has solved this problem with a snubber know exactly what parts they used to put a snubber between the JPI MP line and transducer? 

On another note, I'm not totally in love with JPI's customer service by phone.  

[Bob_Belville]

On 3/2/2016 at 2:40 PM, kortopates said:

For sure a snubber will fix it. But I have seen their firmware update finally resolve the problem with many of our clients. They have released several firmware updates before fixing many so I would encourage you to contact their tech support and see if they have a newer update than what you now have. If they say no, it doesn't hurt to ask them for a snubber. They use to provide them but they are now bent on fixing this in s/w.

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Paul, JPI provided me with a snubber valve that fixed the fluctuating MAP problem several years ago.

Chasing a different problem (OP, as I recall) I shipped them the unit and the transducers. While they had the unit they updated the firmware which was nice in that the new ver. allowed flipping the RPM & MAP displays. Do you know if they have to have the unit to update firmware?

[kortopates]

On 3/2/2016 at 2:40 PM, kortopates said: For sure a snubber will fix it. But I have seen their firmware update finally resolve the problem with many of our clients. They have released several firmware updates before fixing many so I would encourage you to contact their tech support and see if they have a newer update than what you now have. If they say no, it doesn't hurt to ask them for a snubber. They use to provide them but they are now bent on fixing this in s/w.

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Paul, JPI provided me with a snubber valve that fixed the fluctuating MAP problem several years ago.

Chasing a different problem (OP, as I recall) I shipped them the unit and the transducers. While they had the unit they updated the firmware which was nice in that the new ver. allowed flipping the RPM & MAP displays. Do you know if they have to have the unit to update firmware?

I know with the non-TSO'd units that the firmware can be updated in the field quite easily - because I have done it multiple times. But I can't say for sure on the the TSO'd units but I haven't updated one them yet and since they have locked down a lot of what used to be configurable claiming it would violate their TSO requirements it makes me wonder. They certainly have the means to support it but it would probably take a call to JPI to verify.

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[Bob_Belville]

15 hours ago, DXB said:

Reviving this thread...for the second time.   Brief recap- the firmware fix for the EDM-900's MP constantly fluctuating by around +/- 0.5 didn't work.  So I called JPI to send me a snubber.   They sent me one, but it doesn't match the fitting on their MP transducer.   It also doesn't have any markings on it to help me discern the size. Per my avionics guy, it appears to be a 3AN fitting, and I might need a 4AN fitting, but he doesn't have one on hand.  My ability to figure this stuff out on my own is nonexistent.

So i call JPI tech support again. The guy tells me there isn't a snubber that fits their transducer, and I have to find an adapter.  Why didn't they tell me this in the first place rather than just send me something that doesn't fit?  I ask what adapter do I need and where can I get one.  The guy gets in a huff even though I've been polite the whole time.  He says he doesn't know and will back to me....I'm still waiting.

Has anyone here who has solved this problem with a snubber know exactly what parts they used to put a snubber between the JPI MP line and transducer? 

On another note, I'm not totally in love with JPI's customer service by phone.  

It's been 3 years since we installed JPI's snubber. I do recall we had to use an adapter but I do not remember the details. I would think your A&P will know what he/she needs, it isn't anything exotic.  

[Ratherbflying]

7 hours ago, kortopates said:

I know with the non-TSO'd units that the firmware can be updated in the field quite easily - because I have done it multiple times. But I can't say for sure on the the TSO'd units but I haven't updated one them yet and since they have locked down a lot of what used to be configurable claiming it would violate their TSO requirements it makes me wonder. They certainly have the means to support it but it would probably take a call to JPI to verify.

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When I first installed the 900, I had two firmware updates and two different experiences. The first time they insisted that I send the unit in and they had to program it. The second time, 2-3 months later, they sent me a file with instructions on how to update it myself.

I spoke with a JPI Factory Rep at their booth in Oshkosh and he said firmware updates were all done via email now... no need to send the unit back.

[Marauder]

I think the quality of the technical support varies depending on who you are talking with. My radio interference problem troubleshooting with them didn't give me the warm and fuzzies that they wanted to own the problem. They finally conceded that the interference could be caused by the 900 and sent me a ferrite filter to correct it.

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[bradp]

Firmware updates are relatively easy to accomplish in your cockpit.  Sometimes it is updated by electron fairies.  What JPI puts out may be hit or miss, so make sure that you see some early adapters have had good experiences before updating the software.  With your trusty A&P, of course...

http://www.beechtalk.com/forums/viewtopic.php?f=21&t=61509

[FloridaMan]

On 3/2/2016 at 0:51 PM, DXB said:

I'm reviving this fun thread   - I've had my JPI900 about 5 months, and I like it on the whole.   But I have one major beef with it.   My MP bounces by about 0.5" constantly- no big deal, just an annoying distraction in my visual field.  JPI supposedly gave my dealer the firmware fix, but it made no difference at all.  Grrr.   It's particularly annoying because there's no numbers on the analog arc, so no way to set by roughly eyeballing it - the single worst part of the design.  

I'm wishing I kept my analog MP/RPM gauges - particularly since the JPI partially crashed once in flight before the firmware upgrade (lost all engine readings but kept fuel level and a couple other things) - it rebooted after about 30 seconds, just as I was about to pull the breaker to reset.  No way I'm sending back to JPI currently unless it recurs - this would ground me as it's primary.

Should I install a "snubber"?   Should I quit bitching because 0.5" of oscillation is normal?   Should I make some zucchini instead?  Maybe this would mellow me out.

Not normal. When mine was first installed I had an issue with it. The IA who installed it inserted a small restriction in the line to the MP sensor and it is incredibly stable with no "jumping around." It occasionally will shift 0.1 here and there, but it's no different than an analog needle trending on a steam gauge over time with altitude/temperature changes. 

[Brandontwalker]

15 hours ago, Marauder said:

I think the quality of the technical support varies depending on who you are talking with. My radio interference problem troubleshooting with them didn't give me the warm and fuzzies that they wanted to own the problem. They finally conceded that the interference could be caused by the 900 and sent me a ferrite filter to correct it.

 

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Did the ferrite filter work?  I get occasional squelch breaks on my GTN that do not occur on Radio 2.  In candor, I have not thought to try to trace the problem back to the JPI. Squelch has been adjusted way up on the GTN and that corrected the random pops I used to get, but there are some times when it is a solid break.

[Marauder]

15 hours ago, Marauder said: I think the quality of the technical support varies depending on who you are talking with. My radio interference problem troubleshooting with them didn't give me the warm and fuzzies that they wanted to own the problem. They finally conceded that the interference could be caused by the 900 and sent me a ferrite filter to correct it.

 

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Did the ferrite filter work?  I get occasional squelch breaks on my GTN that do not occur on Radio 2.  In candor, I have not thought to try to trace the problem back to the JPI. Squelch has been adjusted way up on the GTN and that corrected the random pops I used to get, but there are some times when it is a solid break.

The filter did fix the problem. There were a lot of squelch opening firmware updates. Make sure you are current on them. Increasing the squelch threshold has other negative effects.

The problem with my JPI only occurred because of the remote annunciator. If he was unplugged, it never opened the squelch. The squelch opening only happened on certain frequencies and not all of them.

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[Marauder]

Reviving this thread...for the second time.   Brief recap- the firmware fix for the EDM-900's MP constantly fluctuating by around +/- 0.5 didn't work.  So I called JPI to send me a snubber.   They sent me one, but it doesn't match the fitting on their MP transducer.   It also doesn't have any markings on it to help me discern the size. Per my avionics guy, it appears to be a 3AN fitting, and I might need a 4AN fitting, but he doesn't have one on hand.  My ability to figure this stuff out on my own is nonexistent.

So i call JPI tech support again. The guy tells me there isn't a snubber that fits their transducer, and I have to find an adapter.  Why didn't they tell me this in the first place rather than just send me something that doesn't fit?  I ask what adapter do I need and where can I get one.  The guy gets in a huff even though I've been polite the whole time.  He says he doesn't know and will back to me....I'm still waiting.

Has anyone here who has solved this problem with a snubber know exactly what parts they used to put a snubber between the JPI MP line and transducer? 

On another note, I'm not totally in love with JPI's customer service by phone.  

Dev - I had the fluctuating MP problem as you recall. It was not fixed with a snubber (never even tried a snubber). They took the unit back and reprogrammed it to make the problem go away. I still see the 0.1 movement but not constantly.

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[DXB]

11 hours ago, Marauder said:

Dev - I had the fluctuating MP problem as you recall. It was not fixed with a snubber (never even tried a snubber). They took the unit back and reprogrammed it to make the problem go away. I still see the 0.1 movement but not constantly.

That's weird. Supposedly the factory sent my avionics guy the firmware fix, but this did nothing to improve the issue.   Then I talked to the CEO at Oshkosh who said the software wouldn't do it - have the factory send you a snubber. They did do this - what I have appears to be the following item:

http://www.swagelok.com/en/catalog/Product/Detail?part=B-4-SA-EW

But it doesn't fit on it's own. I've called them twice since then - today they basically said tough luck - there's not one that will fit on our MP transducer directly, and you're on your own in figuring out any adapters.  So based on the install manual, the setup I have connecting the MP hose to the transducer is as follows:

Anyone know the adapter(s) I need to make these parts come together? I don't know anything about fittings, and I'm surprised JPI wouldn't tell me what I need.

 

 

 

[ArtVandelay]

On 8/17/2016 at 11:24 PM, DXB said:

That's weird. Supposedly the factory sent my avionics guy the firmware fix, but this did nothing to improve the issue.   Then I talked to the CEO at Oshkosh who said the software wouldn't do it - have the factory send you a snubber. They did do this - what I have appears to be the following item:

http://www.swagelok.com/en/catalog/Product/Detail?part=B-4-SA-EW

But it doesn't fit on it's own. I've called them twice since then - today they basically said tough luck - there's not one that will fit on our MP transducer directly, and you're on your own in figuring out any adapters.  So based on the install manual, the setup I have connecting the MP hose to the transducer is as follows:

Anyone know the adapter(s) I need to make these parts come together? I don't know anything about fittings, and I'm surprised JPI wouldn't tell me what I need.

 

 

 

Did you ever get this fixed? I’m having the same issue.

[DXB]

15 minutes ago, teejayevans said:

Did you ever get this fixed? I’m having the same issue.

Yup - my avionics installer ultimately came up with the correct adapter on each side of the snubber - unfortunately I can't tell you the parts as I have no clue what he used.  

[Spurious Moppet]

9 hours ago, DXB said:

Yup - my avionics installer ultimately came up with the correct adapter on each side of the snubber - unfortunately I can't tell you the parts as I have no clue what he used.  

From my own research, here are parts that work. You need two adapters and one snubber. There are no “airplane parts” that I have found that are available but these work:

Earls AT916104ERL Straight -4 AN Swivel to 1/8 Inch Male NPT Adapter from Speedway Motors

Fragola 495021BL Pressure Fitting 1/8 Inch Female to AN4 Male - Black - From Speedway Motors

PS-8G Snubber from Omega.com 

[FloridaMan]

I posted this in another thread. There is a part for NO2 systems that will fix the issue. Drill out an AN fitting and this will fit right in. Search for "53374 00632" to find the part. 

https://www.amazon.com/Nitrous-Express-17020-020-Single/dp/B004LFCMZG

[ArtVandelay]

Just to close the loop, JPI no longer ships the snubbers, they direct you to https://www.omega.com , if you order the PS-8G, it uses 1/8npt and will fit inline with no adapters or drilling required.

 

[carusoam]

See if this is more direct...

https://www.omega.com/pptst/PS_SNUBBERS.html

Interesting that they have three snubber materials based on the viscosity of the material being measured.....

• air
• oil
• water, light oil, (or possibly fuel)

The actual snubber is a density controlled packing as apposed to a small calibrated hole... (old times)

Omega offers the three snubbers with different plumbing fittings to minimize the need for transition pieces...

Go MS!

Best regards,

-a-