I just popped my primary rail out of the block today due to a leaky injector. I have a set of freshly cleaned and flow balanced injectors ready to go in, but when I got the primary rail out I was very shocked and stumped. The injector seals where the rail meets the block were completely broken down and falling apart. These are only 8000mi old. I had a primary rail leak at these seals the first time I put them in so I bought a new set and made sure I was very careful when putting them in. I used white lithium grease to get the rail to slide in and seal nicely.

So I guess what I wanna know is, did I do something wrong? And is there any suggestions on how to put the primary rail and injectors (primary and secondary) in? Thanks.

 

I think you're looking at the injector grommets (chunky, soft rings of rubber). These are not part of the system that seals the pressurized fuel from leaking (the o-rings on the injector do all that); actually they just prevent injected fuel vapor from working back up into the engine compartment.

Since these are soft rubber, they tend to get a little bit pinched and look broken down. IMO, this is not a big deal, since as long as they're largely intact they will do the sealing they need to do. If they are only 8k old I think it's safe to say that's the case here, unless they were really pinched the last time they were put in. The good news is they are only a couple bucks each should you choose to replace them.

Dave

 

They were extremely borken down. Like falling into little pieces. It seems like a chemical breakdown to me. Is white lithium grease what I should be using to seat the primary rail into them?

Also is there any tricks to get the injectors into the rails so they have a better chance of not leaking? Primarys and secondarys...

 

I do not know if lithium grease is the cause of your problem per se, but I have always used regular grease on the o-ring seals when inserting the injectors into the rails. You want something to lubricate the rings so they slide in easily (i.e., to avoid tearing and roll over of seals), but you also want it to be a substance that will dissipate to insure a good long term seal. I have done this in all of my injector installs and have had zero leaks or problems.

 

For the grommets, if they are disintegrated then they need replaced. Sometimes a thin edge of the rubber is coming loose but the bulk of the grommet is fine - to me that's normal. But if it amounts to more than a few rubber shavings coming off, get new ones. Fuel leaking past the bottom o-ring might be responsible for the early demise in your car since they appear to be just ordinary neoprene rubber which can't handle constant exposure to fuel and heat. In the absence of leaks they appear to last much longer than that. I found that a dab of superglue to hold each grommet onto the fuel rails really helped ensure they installed properly.

I would use a touch of motor oil on the o-rings to seat the injectors in the rail. Just moisten the walls of the rail bore. Work them in by twisting the injector and applying pressure - take your time. If they will only go in 95% of the way don't sweat it since the metal injector covers will push it tight.

Dave

 

Yep, I use MMO for these tasks.

 

The manual and the people that cleaned my injectors both said to just use a little clean engine oil.

 

Right on. Thanks guys. Luckily I found some extra primary rail seals in my box of goodies. Should get her runnin again tonight.

Should be fun cause I just installed my new Fire-Powa! Havent got the chance to give it a go yet.