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.

  #11  
Old 06-28-2019, 09:42 AM
WingnutWick's Avatar
WingnutWick WingnutWick is offline
 
Join Date: Jun 2013
Location: Fresno, CA (KFCH)
Posts: 272
Default

Quote:
Originally Posted by DanH View Post
Look at the EFIS photo above. As you further close the throttle plate, does the EGT reduce in step, then fall off a cliff? If so, it's an induction leak...#2 is way lean of peak and eventually goes too lean to fire.
So I tried pulling the prop through as suggested above and I?ve got equal (and normal) compression on all cylinders. Looking at all the pics I snapped yesterday coming in with higher throttle settings engine runs smooth with #EGT higher than the rest by almost 200. As I pull the throttle (or mixture) it does ?fall off a cliff? like Dan mentioned. It does seem like an induction issue does it not?

Will pull the cowling off today and see what I can see around the intake. I?ll keep you all posted! Yesterday was a bad day for the RVs (my gf?s 6s EI started acting up which is why I switched to the 8 for the commute)

Thanks for the ideas folks!
__________________
-Wingnut
F-18E/F, Mk.58, CF-5
Own: RV-8 & RV-10
Reply With Quote
  #12  
Old 06-28-2019, 09:43 AM
WingnutWick's Avatar
WingnutWick WingnutWick is offline
 
Join Date: Jun 2013
Location: Fresno, CA (KFCH)
Posts: 272
Default

Quote:
Originally Posted by Toobuilder View Post
Stuck valve or broken ring lands. Pull the prop through by hand and I'll bet one cylinder is soft.

Do you have the jumpers in the Pmags?
No jumpers but I adjusted them via the software to be appropriate for 0-360 based off threads from here.
__________________
-Wingnut
F-18E/F, Mk.58, CF-5
Own: RV-8 & RV-10
Reply With Quote
  #13  
Old 06-28-2019, 11:50 AM
E. D. Eliot E. D. Eliot is offline
 
Join Date: Dec 2005
Location: San Pedro
Posts: 1,017
Default Start with the simple items

Check the plugs and ht wires.
__________________
Building finally
Reply With Quote
  #14  
Old 06-28-2019, 11:56 AM
WingnutWick's Avatar
WingnutWick WingnutWick is offline
 
Join Date: Jun 2013
Location: Fresno, CA (KFCH)
Posts: 272
Default

Quote:
Originally Posted by E. D. Eliot View Post
Check the plugs and ht wires.
Plugs are pretty new. Less than 20 hrs on them. Wires good.
__________________
-Wingnut
F-18E/F, Mk.58, CF-5
Own: RV-8 & RV-10
Reply With Quote
  #15  
Old 06-28-2019, 12:04 PM
lr172 lr172 is offline
 
Join Date: Oct 2013
Location: Schaumburg, IL
Posts: 6,724
Default

Quote:
Originally Posted by WingnutWick View Post
So I tried pulling the prop through as suggested above and I?ve got equal (and normal) compression on all cylinders. Looking at all the pics I snapped yesterday coming in with higher throttle settings engine runs smooth with #EGT higher than the rest by almost 200. As I pull the throttle (or mixture) it does ?fall off a cliff? like Dan mentioned. It does seem like an induction issue does it not?

Will pull the cowling off today and see what I can see around the intake. I?ll keep you all posted! Yesterday was a bad day for the RVs (my gf?s 6s EI started acting up which is why I switched to the 8 for the commute)

Thanks for the ideas folks!
With the addition of these symptoms, I would put an induction leak at the top of my list of culprits.
__________________
N64LR - RV-6A / IO-320, Flying as of 8/2015
N11LR - RV-10, Flying as of 12/2019
Reply With Quote
  #16  
Old 06-28-2019, 12:05 PM
Toobuilder's Avatar
Toobuilder Toobuilder is offline
 
Join Date: Jul 2009
Location: Mojave
Posts: 4,841
Default

If the prop pulls stiff on all 4 cylinders then the condition cleared itself or there is a significant induction leak. Boot, or more likely a dried out gasket. If it's the gasket then you might want to take a look at the SDS "no leak" induction kit and fix it once and for all.
__________________
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
Reply With Quote
  #17  
Old 06-29-2019, 02:44 AM
PCHunt PCHunt is offline
 
Join Date: Feb 2007
Location: San Diego, CA
Posts: 1,816
Default

+1 for SDS "No induction Leak" mod. My carbureted O-360 idles smooooothly at 450 RPM after installing the mod.

No affiliation, just a happy customer.....
__________________
Pete Hunt, [San Diego] VAF #1069
RV-6, RV-6A, T-6G
ATP, CFII, A&P

2021 Donation+, Gladly Sent
Reply With Quote
  #18  
Old 06-29-2019, 12:33 PM
BobTurner BobTurner is online now
 
Join Date: Dec 2011
Location: Livermore, CA
Posts: 7,859
Default Old trick

Here?s an old trick. With the engine un-cowled, and running at a setting where it?s rough, mist or spray alcohol at each induction tube joint, one at a time. If the engine smooths out, you?ve found a leaking joint.
*****Use all normal cautions working around a turning prop******
Reply With Quote
  #19  
Old 07-01-2019, 12:39 AM
WingnutWick's Avatar
WingnutWick WingnutWick is offline
 
Join Date: Jun 2013
Location: Fresno, CA (KFCH)
Posts: 272
Default That?ll do it!

So took the cowling off and sure enough there was the intake flange sitting at the bottom of the manifold. Not sure how this happened but the two bolts managed to work their way out completely! Gasket nowhere to be found. New gasket and bolts and she?s back to running like her good ol? self! Very odd though, needless to say I checked the rest of the intake bolts.

Thanks for the help all!

Cheers
__________________
-Wingnut
F-18E/F, Mk.58, CF-5
Own: RV-8 & RV-10
Reply With Quote
  #20  
Old 07-01-2019, 10:17 AM
dreed dreed is offline
 
Join Date: Nov 2016
Location: Camas, WA
Posts: 506
Default

Great news and easy fix! Love this forum to read these situations to learn a little something every day and know where to start looking if/when something does need attention.
__________________
Dan Reed
Camas, WA
RV-7A - N167DR
First flight 5/25/2021
Phase 1
2018/19/20 VAF dues paid
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 10:38 PM.


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.