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Old 08-04-2019, 08:28 AM
ltn6a ltn6a is offline
Join Date: Jul 2009
Location: Luton ,Brdfordshire,England
Posts: 55
Default First engine start attempt

Hi all

Looking for some wisdom from the forum.
Attempted first run of my IO-320-B1A in my RV6a
Following the lycoming start sequence ,fuel pump on ,full throttle and full mixture , I got 35psi fuel presss but no indicated fuel flow .
Pump off , mixture idle cut off and throttle 1/4 .
After various attempts managed the odd cylinder to fire but could not get it to run , checked plugs a bit damp but ok . Replaced upper with new plugs .
Still occasional cylinder would fire .
Started investigating the fuel system and with fuel pump on we have good flow right up to the Bendix injector body but regardless of mixture or throttle position no fuel flow / out put.
Pulled the inlet screen filter and it clean so looks as if the injector body is not working .
The engine was stripped and rebuilt about 10 years ago but nothing was done to the injector .

Any advice or suggestions before I pull the injector for a service/ bench test


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Old 08-04-2019, 09:00 AM
Allan Stern Allan Stern is offline
Join Date: Jan 2006
Location: Cape Coral, Florida
Posts: 297
Default Start

Check timing? If rebuit 10 years ago, timing could be off.
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Old 08-04-2019, 09:04 AM
ltn6a ltn6a is offline
Join Date: Jul 2009
Location: Luton ,Brdfordshire,England
Posts: 55

Hi Allen

Will do 5hat but current concern is that we can see no real fuel flow from the injector body out let that feeds the spider.

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Old 08-04-2019, 09:26 AM
Mike S's Avatar
Mike S Mike S is online now
Senior Curmudgeon
Join Date: Sep 2005
Location: Dayton Airpark, NV A34
Posts: 16,114

Verify mixture arm going right direction.
Mike Starkey
VAF 909

Rv-10, N210LM.

Flying as of 12/4/2010

Phase 1 done, 2/4/2011

Sold after 240+ wonderful hours of flight.

"Flying the airplane is more important than radioing your plight to a person on the ground incapable of understanding or doing anything about it."
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Old 08-04-2019, 09:31 AM
ltn6a ltn6a is offline
Join Date: Jul 2009
Location: Luton ,Brdfordshire,England
Posts: 55

Thanks Mike will add that to the todo list

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Old 08-04-2019, 09:56 AM
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Toobuilder Toobuilder is offline
Join Date: Jul 2009
Location: Mojave
Posts: 4,845

After the servo repair, but before you grind on the starter any more (and wipe away ALL lube on the cam), make sure you perform an injector flow test. This will exercise the fuel system and verify the integrity of all components. Assuming you have good spark, it should fire and run.
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
1940 Taylorcraft BL-65
1984 L39C

Last edited by Toobuilder : 08-04-2019 at 02:07 PM.
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Old 08-04-2019, 10:18 AM
ltn6a ltn6a is offline
Join Date: Jul 2009
Location: Luton ,Brdfordshire,England
Posts: 55

Thanks Michael

I will do a search as I don?t recall seeing this in the lycoming operators manual

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Old 08-04-2019, 11:16 AM
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9GT 9GT is offline
Join Date: Jan 2010
Location: Southern Michigan
Posts: 2,192

Purge the air out of the lines by disconnecting the fuel supply line and the fuel divider and running the electric boost pump until you have a solid air free stream of fuel. Make sure you do this safely and run the fuel into a bucket.
David C.
Howell, MI
RV-10: #41686 Under Construction
RV-9A: #90949 Under Construction
RV-10: #40637 Completed/Sold 2016
Cozy MKIV:#656 Completed/Sold 2007
"Donor Exempt" but donated through Dec. 2021
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Old 08-04-2019, 11:25 AM
ltn6a ltn6a is offline
Join Date: Jul 2009
Location: Luton ,Brdfordshire,England
Posts: 55

Hi David

We get good fuel flow to the servo body but no real flow from it .
Exercised the throttle and mixture with fuel pump running no change.
Pulled the servo. Body filter but that was clear

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Old 08-04-2019, 12:17 PM
ethand ethand is offline
Join Date: Mar 2013
Location: San Diego
Posts: 210
Default No Airflow No Fuel Flow

I am not sure this will help but will share my experience with my Airflow Performance throttle body/injection.

Summary is you will not get much fuel flow if there is no metered airflow in the system.

When I did my fuel flow check I disconnected the fuel line at the spider valve and flipped the fuel pump switch to find it trickling out of the hose, not a solid stream. Switched tanks, no joy. I then disconnected the line going into the throttle body, and like you, had full flow. Researched a bit (and confirmed with a call to Don) that there will be very little fuel flow because the system is not seeing the airflow across the venturi to know it should be pumping more gas. One way to test this is flow compressed air in the venturi and see if the FF increases with the electric fuel pump on.

Point is I guess it may or may not be the TB.

Hope that helps.

RV-10 N77319
2192 Days of Building
Completed May 2019
Phase 1 completed Nov 2019
210 hours and counting.....
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