6.9 injector fuel leak

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6.9 injector fuel leak

85blueox
I have installed two different kits on my 6.9s injectors, when I took this truck over it had a bad fuel leak that poured out all over the engine when running.  The first kit I purchased on ebay and it fixed that injector leak but two other injectors started to leak.  It was sugested by others on the internet to try another kit online that was more expensive.  I forget the name of that kit but after instalation one of the injectors continues to leaks continues still.  For both kits I applied the lube on the orings as described, I even read and followed the instructions defying the norm of just jumping in. The leak is a much smaller leak but if the truck sits for more than a few days all the fuel drains and it is harder to start.  What are the recomendations?
85 6.9IDI 4 door rusty beast
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Re: 6.9 injector fuel leak

Ford F834
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Do you still have the original injector caps? Almost 100% of the time fuel leaks are due to deteriorated o rings and fuel hose, not the caps (but they like to sell complete kits). The original GREY plastic caps are a coveted junkyard find, as the quality control on replacements are dodgy as you are experiencing.

You can try replacing the caps that are leaking with different ones… the originals if you still have them, or from your first kit to see if you get lucky and use one that seals. R&D sells billet aluminum fuel rails that replace the caps and hoses, but they are spendy.

https://idiperformance.com/shop/fuel-system/billet-injector-fuel-return-rails/

SHORT BED 4-DOOR DIESEL: 1986 F350 4x4 under construction-- 7.3 IDIT ZF5+GVOD

STRAIGHT SIX 4X4: 1981 F150 2wd to 4x4-- 300 I6 close ratio diesel T19, hydroboost brakes, Saginaw steering

BIG F: 1995 F-Superduty under construction— converting to 6.9L IDI diesel ZF5+DNE2
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Re: 6.9 injector fuel leak

85blueox
I just purchased one, all the reviews are world class so it should solve the problem.
85 6.9IDI 4 door rusty beast
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Re: 6.9 injector fuel leak

Ford F834
Administrator
I have not purchased R&D fuel rails (yet) for myself… but I have purchased other R&D items. Justin designs and sells really good stuff. I have heard that these require some care to install but offer a permanent solution to return rail air intrusion. There are other places for air to get in, but the rails are by far the worst culprit.
SHORT BED 4-DOOR DIESEL: 1986 F350 4x4 under construction-- 7.3 IDIT ZF5+GVOD

STRAIGHT SIX 4X4: 1981 F150 2wd to 4x4-- 300 I6 close ratio diesel T19, hydroboost brakes, Saginaw steering

BIG F: 1995 F-Superduty under construction— converting to 6.9L IDI diesel ZF5+DNE2
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Re: 6.9 injector fuel leak

6.9-250
In reply to this post by 85blueox
I bought one off of ebay or something - lasted about 4 years or so.  A small leak started to show up.  When i took the orings out, many just fell apart.  I purchased a name brand kit - looks the same but hopefully better rubber this time.  Make sure to change all of the return lines.  There are some special seals at the fuel filter outlet line to the injection pump inlet.  I replaced those as well, the local diesel shop had them.  I never thought I would be able to find them.  The water separator is another classic place for air to get in as well.  Mine has been good so far though.  
1985 Ford F-250, 6.9L, Auto C6, 4x4 208F, Extended Cab
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Re: 6.9 injector fuel leak

85blueox
Where is the water separator located?
85 6.9IDI 4 door rusty beast
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Re: 6.9 injector fuel leak

85blueox
In reply to this post by Ford F834
I installed it yesterday, went on ok.  Took about 3 hours, it no longer leaks fuel at any of the injectors.  I will update when it sits awhile to see if it sealed the system or if other places leak.
85 6.9IDI 4 door rusty beast
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Re: 6.9 injector fuel leak

Gary Lewis
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Good news!
Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI

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Re: 6.9 injector fuel leak

Ford F834
Administrator
In reply to this post by 85blueox
The original 6.9 stock water separator was mounted on the firewall next to the brake booster. It is rare to see one still in place. The 7.3 IDI incorporated it into the fuel filter assembly.

SHORT BED 4-DOOR DIESEL: 1986 F350 4x4 under construction-- 7.3 IDIT ZF5+GVOD

STRAIGHT SIX 4X4: 1981 F150 2wd to 4x4-- 300 I6 close ratio diesel T19, hydroboost brakes, Saginaw steering

BIG F: 1995 F-Superduty under construction— converting to 6.9L IDI diesel ZF5+DNE2
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Re: 6.9 injector fuel leak

85blueox
Thats where I looked for it, must have been removed.
85 6.9IDI 4 door rusty beast
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Re: 6.9 injector fuel leak

85blueox
In reply to this post by Ford F834
The R&D injector cover seems to be working.  9 days after installation seems to start right up without cranking, coughing or sputtering.
Ill keep you all posted on how it works.
85 6.9IDI 4 door rusty beast
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Re: 6.9 injector fuel leak

Ford F834
Administrator
Good to hear! Thank you for the update… R&D upgrades can be a little pricey but in my experience so far they are high quality and worth it.
SHORT BED 4-DOOR DIESEL: 1986 F350 4x4 under construction-- 7.3 IDIT ZF5+GVOD

STRAIGHT SIX 4X4: 1981 F150 2wd to 4x4-- 300 I6 close ratio diesel T19, hydroboost brakes, Saginaw steering

BIG F: 1995 F-Superduty under construction— converting to 6.9L IDI diesel ZF5+DNE2
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Re: 6.9 injector fuel leak

85blueox
Installed the R&D fuel rails a month ago, I let it sit all this time just to see if it would loose pressure.  Went out and started it last night and it started just like a new engine.

2 thumbs up for the R&D fuel rails, they were about a 2.5 hour install and not cheap but looks like worth the money and effort.
85 6.9IDI 4 door rusty beast
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Re: 6.9 injector fuel leak

Ford F834
Administrator
That is a good testament to the effectiveness of these rails. Thank you for the update and follow up!
SHORT BED 4-DOOR DIESEL: 1986 F350 4x4 under construction-- 7.3 IDIT ZF5+GVOD

STRAIGHT SIX 4X4: 1981 F150 2wd to 4x4-- 300 I6 close ratio diesel T19, hydroboost brakes, Saginaw steering

BIG F: 1995 F-Superduty under construction— converting to 6.9L IDI diesel ZF5+DNE2
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Re: 6.9 injector fuel leak

Gary Lewis
Administrator
Yes, thanks for the update.  It is good to know that there are products out there that actually solve the problems that these trucks have.  
Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI