I'm so close....

I just finished running new fuel lines and soldering in new injector clips for my newly rebuilt turbo. Before I went to prime the system to check for leaks i spotted that one of my secondaries was lifted up off the intake manifold... upon further inspection it seems that both secondary injectors have a bit of "free play" up and down between the rail and the manifold, so much that the seal almost seems to be compromised when all the way "up" I know this can't be right... what am I missing here?

 

diffusers.

 

That was my first thought, but they are there.... everything is tightened down as it should be, all grommits are there, all o-rings are there, diffusers are in. I should mention that these are aftermarket 720cc secondaries purchased off of a memebr here. Not sure what brand.

 

I think Im just going to bend down the attachments for the rail and get it snug.... I dont want injectors popping up at 12psi.

 

You've got both the top and bottom grommets in place right? Sorry to be redundant, just trying to get a clear picture here.

Do you have a photo of the play or of the injectors? What brand injectors are they?

 

are these stock style injectors in stock rails?

 

stock rails, aftermarket 720 injectors. I'm not sure of the brand, got them from carukorex on here. I managed to bend the tabs on the fuel rail a bit and there isnt near as much play now, and it does take a little force to get them all the way up... I'm thinking with the pressure from the fuel pushing them down I should be ok. Not starting it till thursday so i have some time for opinions.... man it is hot outside.

edit: they are bosch 720's

 

I'd recommend jumping the initial set coupler-type-thing and running the fuel pump with the car off to test for leaks. I did it the opposite way... bolted everything down and started the car, then realized I had problems when fuel was all over the windshield....

 

Yea, I've primed it a bunch of times with no leaks... unfortunately i cant really simulate 12 pounds of boost pushing up on the injectors at the moment...

 

If those are really Bosch 720's they won't even seat properly in the fuel rail. Have you jumpered the fuel pump check connector yet to check for leaks? Can you post a pic of the injector?



if they look like the injector on the left then you're going to have problems. If they look kind of like this Greddy/Denso injector:



then they should fit. The Bosch style injectors have a 14mm oring at the top and the OEM/Denso style have an 11mm o-ring at the bottom. The OEM style injectors also have a flat cushion at the bottom while the Bosch style injectors have another 14mm o-ring

 

Well that's bogus....here's a link to the FS thread. There is a picture in the first post.

https://www.rx7club.com/showthread.p...ight=carukorex

They are like the Bosch ones on the left, but the lower grommet is different. They sit fine in the rail, nice and tight....

 

from that pic you linked to they look like they should have the proper fitment on the top and bottom of the injector. There could be a slight difference in overall length due to different manufacturing tolerances.

Make sure the rail is on there properly and then use the fuel pump diagnostic connector to check for leaks from the top of the injector.

 

Yes, that was my next question. With key to ON, I just jumper a wire from the (+) terminal on the battery to which pin on the yellow connector? The top ("hat" of the T) or bottom?.....sorry for kindergarten description...

 

nevermind, Im an idiot.... found the answer

 

From what I've read and understand, don't you need to trim the plastic around the top end of the injector for it to slide completely into the fuel rail? Or am I thinking of something completely different?

 

No, no trimming req'd. I jumpered the check connector, the system pressurized nicely, no leaks at all. With the system pressurized I couldnt even get the secondary injectors to move a millimeter, nice and snug. Thanks for keeping me sane guys!

 

I've had my share of injectors being taken off and on my engine,lately.
Now. if you put an Oring on the bottom of the injector before the Actual injector gets placed IN the Grommet/diffuser part of the Engine,then it will take up a bit of slack.
It will allow the injectors to sit Tighter in Place when the Rail gets tightened down.
This is Strictly a Do at your own risk thing.It did work for me.

 

If you are concerned about an air leak where the injector sits in the manifold, pressurize the system with a boost leak pressure tester. You should be able to feel air escaping from under the UIM if the injector isn't fully sealed at the bottom.

 

Not to hijack, but are there any good sources for grommets? The typical auto store ones always deteriorate and fall apart VERY quickly. Even with 700 or so miles on my new ones (got them during injector service), they are completely falling apart.

What is everyone here using?