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?

[Ford F834]

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/

[85blueox]

I just purchased one, all the reviews are world class so it should solve the problem.

[Ford F834]

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.

[6.9-250]

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.  

[85blueox]

Where is the water separator located?

[85blueox]

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.

[Gary Lewis]

Good news!

[Ford F834]

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.

[85blueox]

Thats where I looked for it, must have been removed.

[85blueox]

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.

[Ford F834]

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.

[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.

[Ford F834]

That is a good testament to the effectiveness of these rails. Thank you for the update and follow up!

[Gary Lewis]

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.