X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from EXHUB003-2.exch003intermedia.net ([207.5.74.29] verified) by logan.com (CommuniGate Pro SMTP 5.2.14) with ESMTPS id 3756180 for flyrotary@lancaironline.net; Mon, 13 Jul 2009 16:40:22 -0400 Received-SPF: none receiver=logan.com; client-ip=207.5.74.29; envelope-from=jwhaley@datacast.com Received: from EXVMBX003-5.exch003intermedia.net ([207.5.74.45]) by EXHUB003-2.exch003intermedia.net ([207.5.74.29]) with mapi; Mon, 13 Jul 2009 13:39:47 -0700 From: Jeff Whaley To: Rotary motors in aircraft Date: Mon, 13 Jul 2009 13:39:45 -0700 Subject: RE: [FlyRotary] Re: Narrowing in on Cause? [FlyRotary] Re: frustrating couple of days Thread-Topic: [FlyRotary] Re: Narrowing in on Cause? [FlyRotary] Re: frustrating couple of days Thread-Index: AcoCm+Acn6mSJn3BQ8qQVMe1DDe85wBXNOsg Message-ID: References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: multipart/alternative; boundary="_000_C03ABB0A7362B84BB53D544B3C305E0E01403642C910EXVMBX0035e_" MIME-Version: 1.0 --_000_C03ABB0A7362B84BB53D544B3C305E0E01403642C910EXVMBX0035e_ Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Glad I could help Mike, but you may still be wondering why the chip wasn't = fully seated. 1) It was not pushed in far enough at original install - not good; but= not as bad as 2 ... 2) It somehow popped out of the socket. Jeff From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Beh= alf Of Mike Wills Sent: Saturday, July 11, 2009 10:50 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Narrowing in on Cause? [FlyRotary] Re: frustrating= couple of days Tracy, Thanks for the reply. Last week I pulled the EC-2 to take a look at the A/= B input and see if you did anything there to suppress any sort of spike and= to see what would be involved in installing a bypass cap there. While looking around I noted that the B controller chip was not completely = seated in its socket. One corner was sitting pretty high. I pressed on it a= nd it seated with a very clear snap. Jeff Whaley had previously mentioned t= aking a look for this - good catch Jeff! While I had it out i went ahead and installed the bypass cap. I've been out= of town on a gliding trip so havent had time to get it reinstalled and che= ck it out. But I'm hopeful that this will be the cure since there was an ob= vious problem. I'll let you all know a few hours testing time down the road= . Mike Wills RV-4 N144MW ----- Original Message ----- From: Tracy Crook To: Rotary motors in aircraft Sent: Saturday, July 11, 2009 9:54 AM Subject: [FlyRotary] Re: Narrowing in on Cause? [FlyRotary] Re: frustrating= couple of days On a rare check of email at the library here in Colorado and caught this me= ssage. Mike, there is a chance that the inductive spike which happens when select= ing B (or return to A) is causing a problem. It might be aggravated by rel= ocating the selector switch. It is worth trying a capacitor on that line = (A/B select line) to suppress the spike. Tracy On Thu, Jul 2, 2009 at 9:01 AM, sboese > wrote: Ed and Mike, Tracy would be the one to comment on this, if he was available, but it is m= y understanding that both the A and B controllers are running all the time.= The A/B switch operates a relay that just changes which controller's outp= uts are connected to the rest of the plane. When the injector relay change= s contacts there is the possibility for arcing between the contacts dependi= ng on whether or not the injectors were turned on at that time. Tracy said= once that he had trouble with corruption of the controllers probably due t= o this arcing and that was the reason for the transient suppression diodes = in the injector driver circuitry. Changing to the snubber circuitry, possi= bly increased the chance for the arcing problem but helped with injector re= sponse time. A compromise like everything else. Moving the A/B switch sho= uldn't cause a problem unless this has changed the relay response time and = caused an arcing problem. I don't know if the PCM has any circuitry involv= ed with this other than the switch itself. If it does, it's not obvious. = Is there any chance that any of Mike's injectors are drawing more current t= han intended? Wiring for saturated when one or more of them is peak and h= old or otherwise damaged? That could cause arcing and corruption problems. How's that for speculation? Steve Boese -----Original Message----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Ed Anderson Sent: Thursday, July 02, 2009 5:18 AM To: Rotary motors in aircraft Subject: [FlyRotary] Narrowing in on Cause? [FlyRotary] Re: frustrating cou= ple of days I think you may be narrowing in on the cause of your problem, Mike. Remoting the cold start and/or controller selection switch might have unint= ended effects. IF this were the cause, my bet would be on the controller se= lect switch. I don't know what all that switch does - but it clearly trans= fers control of the ignition and injectors to the B controller (when so swi= tched). So several High Power circuits are being turned on (or switched ov= er) to the B controller by a switch that is no longer co-located on the pro= gram Controller PCB. Again, IF this remoting of the switches could cause t= his, the question is HOW? Not certain of what de-bounce routine Tracy uses - whether software or hard= ware - but if you turned on the switch to B controller, I would presume the= B controller immediately loads the MAP into its working memory. I would a= ssume the Map (as well as other data such as staging) would normally resid= e in EEPROM and upon activation one of the first things the B controller wo= uld do is to load this MAP and data. Now, lets say a second voltage spike = from the un-debounced switch were sent to the B controller during the time = it was loading the fuel Map, it could cause the chip to do a reset during t= his interval. That could result in part of the MAP or other data stored in= EEPROM getting corrupted. I don't know the internal coding for moving data= from EEPROM to working memory inside the EC2, I do know that for the Seri= al data its code is in MIDI format. Using the MIDI format means if only one bit is corrupted out of the 256 byt= es used to transmit the Map over the serial link - then all data after that= point is corrupted. That is one of the reasons I had to give the Rs232 US= ART comm. Module in my EFISM chip top priority during interrupts. I can lo= se any number of injector pulses and it not affect its accuracy enough to d= isplay - but corruption of the most significant bit of the High byte MIDI p= air during the MAP serial transmission and the remaining bytes are hopeless= ly corrupted. I was pretty confident the problem was not caused by the EFISM as it has n= o way to talk to the B controller, but glad to have it confirmed. The only= way I can see the EFISM affecting the B controller is rather round about. = You would have to 1st make the change to the A MAP using the EFISM and th= en use the EC2 to copy the A MAP to the B MAP. Even then you can not chang= e the staging point using the EFISM only the Map and ignition. A second thought is whether any "ground currents" could be in play. You ha= ve probably already done this, but try connecting an alligator clamp (or yo= ur favorite attachment device) to the ground of your controller switch and = hook the other end to the grounding stud on the EC2. If a ground circuit c= urrent/voltage was playing a role this might eliminate it. Good luck on your trouble shooting. Don't give up - I think you may be on = the right track. Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://www.andersonee.com http://www.dmack.net/mazda/index.html http://www.flyrotary.com/ http://members.cox.net/rogersda/rotary/configs.htm#N494BW http://www.rotaryaviation.com/Rotorhead%20Truth.htm ________________________________ From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mike Wills Sent: Thursday, July 02, 2009 12:37 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: frustrating couple of days So I vented to you guys, lost some sleep last night pondering this, wasted = more time today thinking about it, and then went back to the airport to che= ck things out. I had previously made all of the changes Tracy recommended in case there wa= s an issue with ground or supply noise. I didnt believe that was the proble= m before, but with no better ideas went ahead and made the changes. I'm now= pretty sure that the electrical system is solid. Another possibility was that there was something about the EFISM installati= on that caused this problem. Not sure how this could be the case but the EF= ISM does have the capability to write to the MCT, so maybe something was ge= tting scrambled in the process? I disconnected the EFISM. And the EFISM was disconnected yesterday when thi= s latest problem occured, so its not the cause. Yesterday just before I qui= t in disgust I reconnected the EFISM and captured the MCT to make sure it h= adnt been corrupted. It looked fine and thats why it was so puzzling. Today when I started the engine it was clearly still screwed up. I put the = EFISM in EC2 monitor mode and immediately saw the problem. This latest prob= lem was due to the fact that my A controller injector staging point had bee= n corrupted and set to 12" MAP. The engine sure wont idle on 4 injectors! I= reset the staging point to where it belongs and the engine is back to runn= ing as it should. I now have 5 known episodes of spontaneous changes to the EC2 (possibly mor= e). The first time the staging point was erased and the secondaries wouldnt= come on. The next 3 cases (twice in the past couple of days) the B control= ler lost its program (since I dont have a way to view the B MCT I dont actu= ally know whats happening here, just that the engine immediately dies when = I flip to B). And then this last episode with the staging point resetting t= o 12". I say there may have actually been more cases because my engine has = never really ran well on the B controller after doing an A to B copy. But i= t does run - usually. So Ed asks is there an action or sequence of actions that may be related? W= ell the common thread here is switching to B. I ran this engine for about 2= 0 hours of ground testing before I noted the first instance of this occurin= g. And this coincides with when I started actually flying the airplane - an= d routinely switching to B as part of my pre takeoff checklist. Then I stop= ped flying about 4 months ago to make all of these changes and further tune= the engine. During this time I dont think I ever switched to B and noted n= o problems. This past weekend I started prepping to fly and went through my= typical pre takeoff prep and once again problems. Started troubleshooting = by routinely checking the B controller and once again corrupted the EC2, th= is time the staging point. Since my most consistent indicator of a change is corruption of the B MCT i= ts hard to say for sure, but if i can force the staging point screw up a fe= w times by switching to B I'll be convinced. I should note that my install = is not standard for the EC2 PCM. I removed the A/B switch, Cold Start switc= h, and Coil Test switch from the PCM and remoted them to my instrument pane= l. Tracy noted this as an optional way to do things in my EC2 manual. I don= t recall how Tracy implements these switches, but I assume they are SPST to= a pullup resistor on the EC2. I dont know if he has any circuitry to de-bo= unce or noise filter the switch input? I dont even know for sure that this = is the cause but seems to be the most reasonable explanation at this point.= Stay tuned. Mike Wills RV-4 N144MW ----- Original Message ----- From: Ed Anderson To: Rotary motors in aircraft Sent: Wednesday, July 01, 2009 6:15 AM Subject: [FlyRotary] Re: frustrating couple of days Mike, its got to be frustrating to have it run well for a couple of months = and just when you have convinced yourself the problem is gone, it comes ba= ck. I presume there is nothing (no action, sequence of actions) that you can th= ink of having taken recently - any different than you have done during the = months the engine ran well that you can think of. Nothing different perhap= s in getting ready for another flight? Since the fuel map is stored in non-volute memory, it's hard to figure out = how it is being re-written or destroyed. Normally (as you know) access to = EEPROM on a chip is a rather non-trivial process. Since the A and B contr= oller are two different chips, I suppose there could be a problem with the = B chip - but, while that does happen, it's pretty rare. Have not had one m= yself (yet). You are able to copy over the A MAP to the B MAP and it apparently does the= copy, but then something causes it to be re-written with garbage. You do = not have Auto tune and I presume you do not attempt to change the B MAP - b= ut it changes on its own. It sounds as it the changes to B happen whether = you have selected B controller or not - is that correct. Or does it only h= appen when you are using the B controller or can you tell. Ed Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://www.andersonee.com http://www.dmack.net/mazda/index.html http://www.flyrotary.com/ http://members.cox.net/rogersda/rotary/configs.htm#N494BW http://www.rotaryaviation.com/Rotorhead%20Truth.htm ________________________________ From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mike Wills Sent: Wednesday, July 01, 2009 12:10 AM To: Rotary motors in aircraft Subject: [FlyRotary] frustrating couple of days I havent flown my RV since a couple of cases of lost data in the EC2 back i= n february. Spent the last few months making a bunch of mods, some suggeste= d by Tracy, others were things that I thought might increase long term reli= ability. Also had to fix leaking fuel tanks in the ensuing period. Been working up toward renewing flight testing. Engine has been running rea= lly well for the last few months. Thought that the problem was cured, thoug= h not clear how. Then on saturday found that once again my B controller had= lost all data. Engine wouldnt run at any throttle setting on B. Restored t= he B controller by copying A > B. Last night after work ground ran the engine for about 30 minutes at various= throttle settings and it ran as good as always. Also ran fine on the B con= troller. Tonight after work I fired it up. Ran fine initially. After about 15 minute= s noted some minor surging at a couple of throttle settings below 2000 RPM.= Also noticed that in this RPM range where the mixture had previously been = fine, my mixture monitor is off the scale lean. Slowly got worse, to the po= int that it wouldnt idle at what was previously a solid 1350RPM. Couldnt ge= t it to run at all below 1500, everything between 1500 and about 3000 RPM p= retty rough. Everything over 3000 is fine. No idea what caused this change.= I put the airplane away and walked away in disgust. I'm back to where I wa= s a year ago and I'm just about fed up with this thing. Mike Wills RV-4 N144MW __________ Information from ESET NOD32 Antivirus, version of virus signatur= e database 3267 (20080714) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com __________ Information from ESET NOD32 Antivirus, version of virus signatur= e database 3267 (20080714) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com --_000_C03ABB0A7362B84BB53D544B3C305E0E01403642C910EXVMBX0035e_ Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Glad I could help Mike, but you may still be wondering why t= he chip wasn’t fully seated.

1)&n= bsp;     It was not pushed in far enough at original install – = not good; but not as bad as 2 …

2)&n= bsp;     It somehow popped out of the socket.

Jeff

 

From: Rotary motors= in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mike Will= s
Sent: Saturday, July 11, 2009 10:50 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Narrowing in on Cause? [FlyRotary] Re: frustrating couple of days

 

Tracy,

 

 Thanks for the reply. Last week I pulled the EC-2 to take a look at the A/B input = and see if you did anything there to suppress any sort of spike and to see what would be involved in installing a bypass cap there.

 

While looking around I noted that the B controller chip was not completely seated= in its socket. One corner was sitting pretty high. I pressed on it and it seat= ed with a very clear snap. Jeff Whaley had previously mentioned taking a look = for this - good catch Jeff!

 

While I had it out i went ahead and installed the bypass cap. I've been out of to= wn on a gliding trip so havent had time to get it reinstalled and check it out= . But I'm hopeful that this will be the cure since there was an obvious probl= em. I'll let you all know a few hours testing time down the road.

 

Mike Wills

RV-4 N144MW 

----- Original Message -----

From: Tracy Crook

Sent: Saturday, July= 11, 2009 9:54 AM

Subject: [FlyRotary] Re= : Narrowing in on Cause? [FlyRotary] Re: frustrating couple of days

 

On a rare check of email at the library here in Colora= do and caught this message.

 

Mike,  there is a chance that the inductive spike= which happens when selecting B (or return to A) is causing a problem.  It mi= ght be aggravated by relocating the selector switch.   It is wor= th trying a capacitor on that line (A/B select line)  to suppre= ss the spike.

 

Tracy

On Thu, Jul 2, 2009 at 9:01 AM, sboese <sboese@uwyo.edu> wrote:

Ed and Mike,

 

Tracy would be the one to comment on this, if he was available, but it is my understanding that both the A and B controllers are running all the time.&n= bsp; The A/B switch operates a relay that just changes which controller’s outputs are connected to the rest of the plane.  When the injector rel= ay changes contacts there is the possibility for arcing between the contacts depending on whether or not the injectors were turned on at that time. = ; Tracy said once that he had trouble with corruption of the controllers prob= ably due to this arcing and that was the reason for the transient suppression di= odes in the injector driver circuitry.  Changing to the snubber circuitry, possibly increased the chance for the arcing problem but helped with inject= or response time.  A compromise like everything else.  Moving the A/= B switch shouldn’t cause a problem unless this has changed the relay response time and caused an arcing problem.  I don’t know if the= PCM has any circuitry involved with this other than the switch itself.  If= it does, it’s not obvious.  Is there any chance that any of Mike’s injectors are drawing more current than intended?   Wiring for saturated when one or more of them is peak and hold or otherwise damaged?  That could cause arcing and corruption problems. 

 

How’s that for speculation?

 

Steve Boese 

 

-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lan= caironline.net] On Behalf Of Ed Anderson
Sent: Thursday, July 02, 2009 5:18 AM
To: Rotary motors in aircraft

Subject: [FlyRotary] Narrowing in on Cause? [FlyRotary] Re: frustrating couple of days

 

I think you may be narrowing in on the cause of your problem, M= ike.

 

Remoting the cold start and/or controller selection switch migh= t have unintended effects. IF this were the cause, my bet would be on the controller select switch.  I don’t know what all that switch doe= s – but it clearly transfers control of the ignition and injectors to t= he B controller (when so switched).  So several High Power circuits are bei= ng turned on (or switched over) to the B controller by a switch that is no lon= ger co-located on the program Controller PCB.  Again, IF this remoting of = the switches could cause this, the question is HOW?

 

Not certain of what de-bounce routine Tracy uses – whethe= r software or hardware – but if you turned on the switch to B controlle= r, I would presume the B controller immediately loads the MAP into its working memory.  I would assume the Map (as well as other data such as staging= )  would normally reside in EEPROM and upon activation one of the first things the B controller would do is to load this MAP and data.  Now, l= ets say a second voltage spike from the un-debounced switch were sent to the B controller during the time it was loading the fuel Map, it could cause the = chip to do a reset during this interval.  That could result in part of the = MAP or other data stored in EEPROM getting corrupted. I don’t know the internal coding for moving data from EEPROM to working memory inside the EC= 2,  I do know that for the Serial data its code is in MIDI format.

 

Using the MIDI format means if only one bit is corrupted out of= the 256 bytes used to transmit the Map over the serial link – then all da= ta after that point is corrupted.  That is one of the reasons I had to gi= ve the Rs232 USART comm. Module in my EFISM chip top priority during interrupts.  I can lose any number of injector pulses and it not affec= t its accuracy enough to display – but corruption of the most significa= nt bit of the High byte MIDI pair during the MAP serial transmission and the remaining bytes are hopelessly corrupted. 

 

 I was pretty confident the problem was not caused by the EFISM as it has no way to talk to the B controller, but glad to have it confirmed.  The only way I can see the EFISM affecting the B controlle= r is rather round about.   You would have to 1st make the change to the A MAP using the EFISM and then use the EC2 to copy the A MAP = to the B MAP.  Even then you can not change the staging point using the E= FISM only the Map and ignition.

 

A second thought is whether any “ground currents” c= ould be in play.  You have probably already done this, but try connecting a= n alligator clamp (or your favorite attachment device) to the ground of your controller switch and hook the other end to the grounding stud on the EC2.  If a ground circuit current/voltage was playing a role this might eliminate it.

 

Good luck on your trouble shooting.  Don’t give up – I think you may be on the right track.

From: Rotary motors= in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mike Wills
Sent: Thursday, July 02, 2009 12:37 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: frustrating couple of days

 

So I vented to you guys, lost some sleep last night pondering this, wasted mor= e time today thinking about it, and then went back to the airport to check th= ings out.

 

I had previously made all of the changes Tracy recommended in case there was = an issue with ground or supply noise. I didnt believe that was the problem bef= ore, but with no better ideas went ahead and made the changes. I'm now pretty su= re that the electrical system is solid.

 

Another possibility was that there was something about the EFISM installation that caused this problem. Not sure how this could be the case but the EFISM does have the capability to write to the MCT, so maybe something was getting scrambled in the process?

 

I disconnected the EFISM. And the EFISM was disconnected yesterday when this latest problem occured, so its not the cause. Yesterday just before I quit = in disgust I reconnected the EFISM and captured the MCT to make sure it hadnt = been corrupted. It looked fine and thats why it was so puzzling.

 

Today when I started the engine it was clearly still screwed up. I put the EFISM = in EC2 monitor mode and immediately saw the problem. This latest problem was d= ue to the fact that my A controller injector staging point had been corrupted = and set to 12" MAP. The engine sure wont idle on 4 injectors! I reset the staging point to where it belongs and the engine is back to running as it should.

 

I now have 5 known episodes of spontaneous changes to the EC2 (possibly more)= . The first time the staging point was erased and the secondaries wouldnt com= e on. The next 3 cases (twice in the past couple of days) the B controller lo= st its program (since I dont have a way to view the B MCT I dont actually know whats happening here, just that the engine immediately dies when I flip to = B). And then this last episode with the staging point resetting to 12". I = say there may have actually been more cases because my engine has never really = ran well on the B controller after doing an A to B copy. But it does run - usua= lly.

 

So Ed asks is there an action or sequence of actions that may be related? Well= the common thread here is switching to B. I ran this engine for about 20 hours = of ground testing before I noted the first instance of this occuring. And this coincides with when I started actually flying the airplane - and routinely switching to B as part of my pre takeoff checklist. Then I stopped flying a= bout 4 months ago to make all of these changes and further tune the engine. Duri= ng this time I dont think I ever switched to B and noted no problems. This pas= t weekend I started prepping to fly and went through my typical pre takeoff p= rep and once again problems. Started troubleshooting by routinely checking the = B controller and once again corrupted the EC2, this time the staging point.

 

Since my most consistent indicator of a change is corruption of the B MCT its har= d to say for sure, but if i can force the staging point screw up a few times by switching to B I'll be convinced. I should note that my install is not stan= dard for the EC2 PCM. I removed the A/B switch, Cold Start switch, and Coil Test switch from the PCM and remoted them to my instrument panel. Tracy noted th= is as an optional way to do things in my EC2 manual. I dont recall how Tracy implements these switches, but I assume they are SPST to a pullup resistor = on the EC2. I dont know if he has any circuitry to de-bounce or noise filter t= he switch input? I dont even know for sure that this is the cause but seems to= be the most reasonable explanation at this point. Stay tuned.

 

Mike Wills

RV-4 N144MW

----- Original Message -----

From: Ed Anderson

Sent: Wednesday, Jul= y 01, 2009 6:15 AM

Subject: [FlyRotary] Re= : frustrating couple of days

 

Mike, its got to be frustrating to have it run well for a coupl= e of months and just when you have convinced  yourself the problem is gone,= it comes back.

 

I presume there is nothing (no action, sequence of actions) tha= t you can think of having taken recently - any different than you have done d= uring the months the engine ran well that you can think of.  Nothing differe= nt perhaps in getting ready for another flight?

 

Since the fuel map is stored in non-volute memory, it’s h= ard to figure out how it is being re-written or destroyed.  Normally (as y= ou know) access to EEPROM on a chip is a rather non-trivial process.   Since the A and B controller are two different chips, I suppose there could be a problem with the B chip – but, while that does happen, it’s pretty rare.  Have not had one myself (yet).

 

You are able to copy over the A MAP to the B MAP and it apparen= tly does the copy, but then something causes it to be re-written with garbage.  You do not have Auto tune and I presume you do not attempt t= o change the B MAP – but it changes on its own.  It sounds as it t= he changes to B happen whether you have selected B controller or not – i= s that correct.  Or does it only happen when you are using the B control= ler or can you tell.

 

 

Ed

 

From: Rotary motors= in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mike Wills
Sent: Wednesday, July 01, 2009 12:10 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] frustrating couple of days

 

I havent flown my RV since a couple of cases of lost data in the EC2 back in february. Spent the last few months making a bunch of mods, some suggested = by Tracy, others were things that I thought might increase long term reliabili= ty. Also had to fix leaking fuel tanks in the ensuing period.<= /o:p>

 

Been working up toward renewing flight testing. Engine has been running really w= ell for the last few months. Thought that the problem was cured, though not cle= ar how. Then on saturday found that once again my B controller had lost a= ll data. Engine wouldnt run at any throttle setting on B. Restored the B controller by copying A > B.

 

Last night after work ground ran the engine for about 30 minutes at various thro= ttle settings and it ran as good as always. Also ran fine on the B controller.

 

Tonight after work I fired it up. Ran fine initially. After about 15 minutes noted = some minor surging at a couple of throttle settings below 2000 RPM. Also noticed that in this RPM range where the mixture had previously been fine, my mixtu= re monitor is off the scale lean. Slowly got worse, to the point that it wouldnt idle at what was previously a solid 1350RPM. Couldnt get it to run = at all below 1500, everything between 1500 and about 3000 RPM pretty rough. Everything over 3000 is fine. No idea what caused this change. I put the airplane away and walked away in disgust. I'm back to where I was a year ag= o and I'm just about fed up with this thing.

 

Mike Wills

RV-4 N144MW



__________ Information from ESET NOD32 Antivirus, version of virus signatur= e database 3267 (20080714) __________

The message was checked by ESET NOD32 Antivirus.

http://www.eset.com<= o:p>



__________ Information from ESET NOD32 Antivirus, version of virus signatur= e database 3267 (20080714) __________

The message was checked by ESET NOD32 Antivirus.

http://www.eset.com<= o:p>

 

--_000_C03ABB0A7362B84BB53D544B3C305E0E01403642C910EXVMBX0035e_--