VansAirForceForums  
Home > VansAirForceForums

-POSTING RULES
-Advertise in here!
- Today's Posts | Insert Pics

Keep VAF Going
Donate methods

Point your
camera app here
to donate fast.

  #1  
Old 12-18-2015, 10:13 PM
AX-O's Avatar
AX-O AX-O is offline
 
Join Date: Jun 2005
Location: SoCal
Posts: 2,545
Default PMAG issue/fix

Today i wanted to go flying. So i did the preflight, had my test plan ready and pushed the plane out. During the preflight i moved the exhaust pipes and the right pair felt a little different. Humm, that is a little weird.

I started the plane and all appered to be working well. When i did the mag checks i knew something was wrong immediately. After troubleshooting i noticed that the number 3 cylinder egt was dropping as soon as i killed the good mag. Pretty easy to see with the engine monitor.

So i taxied back and started to remove the cowl. As soon as the cowl was off, the problem was easily spotted, one of the PMAG wires (#3, imagine that) came off the back of the PMAG. I put the wire back in but the standard click when correctly set on the PMAG did not happen. I found an unused new wire and gave it a try. Click!! So i checked some of the other wires and 3 more were extremely easy to remove. No click. I took some needle nose pliers and crimped the metal portion of the wire. Now they all click and feel secure.

I am not sure what happen. The plane now has 15 hours on it. I know that when i made the wires, they clicked nicely when installed. I will keep an eye on them.

As i was checking around before putting the cowl back on, i found a broken adel clamp. The one that held the right exhaust pair to the engine mount. Well that makes sense.

Got everything back together and went flying. Had a great flight. Has anyone had a similar issue with the wire coming off the back of the PMAG? My guess is mine came off during last flight because the previous mag check passed on the ground.
__________________
Axel
RV-4 fastback thread and Pics
VAF 2020 paid VAF 704
The information that I post is just that; information and my own personal experiences. You need to weigh out the pros and cons and make up your own mind/decisions. The pictures posted may not show the final stage or configuration. Build at your own risk. Further more, these are my opinions and not those of my employer.
Reply With Quote
  #2  
Old 12-18-2015, 10:40 PM
lr172 lr172 is offline
 
Join Date: Oct 2013
Location: Schaumburg, IL
Posts: 6,681
Default

I have no experience with Pmags, but quite a bit with auto ignition. Usually the only terminals that click on the coil side are the GM HEI style. Inside the rubber boot is a steel band in the shape of a C. It has a spring tension and ball socket arrangement to hold it on the terminal. It "clicks" as it goes over the fat part of the male post. If your connectors have lost their temper after 15 hours (or at all for that matter), they are of poor quality and should be replaced. While squeezing them worked initially, they have proven that they will not hold their shape.

Consider yourself lucky that only one failed and you caught it on the ground. I would replace them without delay. This is not a normal failure for HEI style connectors. You don't want critical parts that require this type maintenance. No place to pull over in the sky with your pliers :-)

Larry
__________________
N64LR - RV-6A / IO-320, Flying as of 8/2015
N11LR - RV-10, Flying as of 12/2019
Reply With Quote
  #3  
Old 12-18-2015, 10:52 PM
AX-O's Avatar
AX-O AX-O is offline
 
Join Date: Jun 2005
Location: SoCal
Posts: 2,545
Default

Larry, where would you buy yours? I got mine with the PMAGSs.
__________________
Axel
RV-4 fastback thread and Pics
VAF 2020 paid VAF 704
The information that I post is just that; information and my own personal experiences. You need to weigh out the pros and cons and make up your own mind/decisions. The pictures posted may not show the final stage or configuration. Build at your own risk. Further more, these are my opinions and not those of my employer.
Reply With Quote
  #4  
Old 12-19-2015, 07:36 AM
N941WR's Avatar
N941WR N941WR is offline
 
Join Date: Jan 2005
Location: SC
Posts: 12,887
Default

In 700 hours I have never had a plug wire come off the P-mags or sparkplugs.

Is it possible that your connector wasn't pushed all the way in until it "clicked"?

BTW, The RICommander can tell you if a wire has come off, or if you have a bad plug, or ...
__________________
Bill R.
RV-9 (Yes, it's a dragon tail)
O-360 w/ dual P-mags
Build the plane you want, not the plane others want you to build!
SC86 - Easley, SC
www.repucci.com/bill/baf.html
Reply With Quote
  #5  
Old 12-19-2015, 08:51 AM
Gisnar Gisnar is offline
 
Join Date: Nov 2012
Location: Northern Nevada
Posts: 140
Default

I also run dual Pmags on an IO320. And yes I have had this happen.
My cure is to use a dab of dielectric grease followed by a zip tie about the rubber boot.
Keeps out moisture out as well as keeps the boot tight.
Reply With Quote
  #6  
Old 12-19-2015, 10:00 AM
AX-O's Avatar
AX-O AX-O is offline
 
Join Date: Jun 2005
Location: SoCal
Posts: 2,545
Default

Quote:
Originally Posted by N941WR View Post
Is it possible that your connector wasn't pushed all the way in until it "clicked"?

BTW, The RICommander can tell you if a wire has come off, or if you have a bad plug, or ...
Bill, I made sure they all clicked and were set correctly. Your commander is a future upgrade. Just not there yet. Don't have the time or money right now.

Quote:
Originally Posted by Gisnar View Post
I also run dual Pmags on an IO320. And yes I have had this happen.
My cure is to use a dab of dielectric grease followed by a zip tie about the rubber boot.
Keeps out moisture out as well as keeps the boot tight.
Good idea. Thanks.
__________________
Axel
RV-4 fastback thread and Pics
VAF 2020 paid VAF 704
The information that I post is just that; information and my own personal experiences. You need to weigh out the pros and cons and make up your own mind/decisions. The pictures posted may not show the final stage or configuration. Build at your own risk. Further more, these are my opinions and not those of my employer.
Reply With Quote
  #7  
Old 12-19-2015, 10:10 AM
lr172 lr172 is offline
 
Join Date: Oct 2013
Location: Schaumburg, IL
Posts: 6,681
Default

Quote:
Originally Posted by AX-O View Post
Larry, where would you buy yours? I got mine with the PMAGSs.
I would order a set of high quality auto ignition wires, like Accel. I got their 5000 series for my EI set up. They have SS connectors instead of brass. Less than $50 on Amazon. They are custom though and you will need to crimp them yourself.

Larry
__________________
N64LR - RV-6A / IO-320, Flying as of 8/2015
N11LR - RV-10, Flying as of 12/2019
Reply With Quote
  #8  
Old 12-19-2015, 11:14 AM
Toobuilder's Avatar
Toobuilder Toobuilder is offline
 
Join Date: Jul 2009
Location: Mojave
Posts: 4,841
Default

The coil side of the Pmag is not a standard terminal end. Similar in concept, but about half the contact area as a spark plug/GM HEI terminal. I dont know what it is used on the in the automotive world, but Axel, I do have a few laying around of you get stuck.

I think the actual wire that Brad uses is of reasonable quality, but that too is available in bulk from a myriad of sources (I bought mine from Summit when I installed the CPi system, along with terminals and boots - all in bulk).
__________________
WARNING! Incorrect design and/or fabrication of aircraft and/or components may result in injury or death. Information presented in this post is based on my own experience - Reader has sole responsibility for determining accuracy or suitability for use.

Michael Robinson
______________
Harmon Rocket II -SDS EFI
RV-8 - SDS CPI
1940 Taylorcraft BL-65
1984 L39C

Last edited by Toobuilder : 12-19-2015 at 11:17 AM.
Reply With Quote
  #9  
Old 12-19-2015, 01:21 PM
flynwest flynwest is offline
 
Join Date: May 2008
Location: Sacramento
Posts: 398
Default coil ends

I could not find the coil ends locally. Had to get them from Brad.
__________________
Horse Power is good, more is better and
Too Much is Just Right
RV 8 Super charged Barrett IO-390
RV 8 Fast back built and sold
Dues paid 2021
Dan "Nordo" West
Reply With Quote
  #10  
Old 12-19-2015, 05:20 PM
APACHE 56 APACHE 56 is offline
 
Join Date: Jan 2008
Location: MERRITT ISLAND, FL
Posts: 360
Default True confessions

Quote:
Originally Posted by AX-O View Post
. Has anyone had a similar issue with the wire coming off the back of the PMAG? My guess is mine came off during last flight because the previous mag check passed on the ground.
Axel,
Had this happen not once but several times ( I am a slow learner). Finally it took a telephone tutorial from Brad to solve the problem. You have to take a pair pliers and squeeze the connectors ever so slightly so that they make a good connection. It was so simple and obvious and I cannot explain why the devil it didn't occur to me when I installed the doggone things. Haven't had a bit of trouble after that.
__________________
Don Stiver
RV8 "Little Pill" N6371S, Merritt Island, Fl.
BPE IO-390, Dual P-mag, MT 3-blade, AFP system
Steen Skybolt: Sold
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 05:40 AM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.