Ok, I am gettin the new fuel system installed and need some help from guys who have done it before.

My new setup:
- Full KGParts kit, top feed pri and sec rails, all SS braided lines, et
- pri injectors = 720
- sec injectors = 1680


My questions:

1) When I took the old primary injectors out, there is a diffuser/seal down in the hole, I leave that in there right? Other wise there is no rubber seal to seat with the new injector spacer, right?

2) When I took the secondary injectors out there is a rubber seal then the plastic diffuser thing under it, you have to take the diffuser thing out for the new injector to seat, BUT do you keep the old rubber seal or take them both out and not use anything? Same as a bove here, if you do not use it then there is nothing to seal against the spacer, but maybe thats ok?

3) The kit came with 2 sets of spacers for the new injectors. One set was a little taller than the other set. Do the taller ones go on the 720s or the 1680s?

Any help would be appreciated!!

 

wow, not one reply?

 

You might wanna try to pm jdhuegel1 , look like he did one of the first kg fual rail change...


https://www.rx7club.com/forum/showth...highlight=fuel

 

Damain,

1. (and 3.) I took them out. All that I have sitting in the primary hole is the taller pair of sleaves.

2. I took that stuff out too....again all that is in the secondary hole is the shorter sleaves.

I have ran the secondaries like that for a year. Just got the primary sleaves and I am sure the sleaves will be better than the "rig" I did (which actually worked fine but it was a "rig" )

Also I have done my fuel system 5 times (5 different ways) and would be glad to talk to you about what you are doing and what I have learned. Send me a pm and I'll send you my number.

 

Recommend reading:

http://www.nopistons.com/forums/inde...howtopic=24883

and here are NewbernD's bushings for the secondary injectors (recommended also)

http://dave.newbern.org/rx7/InjectorBushing/

PM me if you need any help. Like Shawn, I've had my fuel system in and out like 50+ times!

edit - had to fix the first link...

 

thansk for al the great info guys.... I'll dig in to the links and suggestions.

 

Just bookmarking.

 

yep, im gonna do a lot of printing of these pages for my next trip to the speedshop :-)

 

hey shawn, thanks for the help, ill pm ya

 

good links, thanks... im gonna go another round on it and will pm ya if i hit a hurdle.

 

Cool. Happy to help.

FYI - DON'T route the secondary rail output to FPR line like I did in the first few pics on that thread.. You don't want that line sitting over the turbo. Swing that puppy around to the driver side! I was so excited to get the fuel system, I didn't even pay attention to what I was doing!

Justin

 

thanks for the heads up :-)

 

You have to remove the diffusers. Get NewbernD's spacer, it works much better than the hose. You might want to get some 90 degree AN fittings to connect to your FPR depending on where you have it mounted.

 

ok, now the only thing i dont understand is how the injector/spacer combo seals with the lim when the stock diffusers and rubber seals are removed.

i just cant see how the metal spacer/sleeve seals with the metal uim with no rubber seal?

the bottom injector o-ring seals with the spacer/sleeves, not the lim, so what am i missing here, there has to be some sort of rubber seal between the sleeve/spacer and lim, right?

 

ok, sounds like they just go in there, no rubber seals (crossing fingers) :-)

 

For reduced worry, you could add them but you don't need the rubber spacers if you have the aluminum sleeves for the injector holes. The injector o-rings should seal tightly and the aluminum sleeves should also fit snug.

The o-ring on the injector should touch the bottom of the LIM or housing.

 

Damian.. honestly, the answer depends on the fit. I'm sure Kieth can attest to the same fact that not all injector bore's are machined with tolerances consistent enough to make an insert fit "perfectly." At least these were my observations. And while I made a set of these that featured an o-ring it's really not practical.

If they look like you could press them in and they would be tight, You might just press them in. More than likely they're just a little small. I would recommend using a small amount of RTV in there to seal them. If they're loose I would NOT let them rattle around. It'll leak boost (although not much.)

Hope that helps..

Dave

 

thanks for the clarification, but one thing seems off with mine, you said:

>>The o-ring on the injector should touch the bottom of the LIM or housing.[/

and that makes sense to me in terms of making a good seal, however, the sleeves on my primaries cover the injectors o-ring all the way, the oring never gets to hit the LIM housing. that is what im worried about, where on the secondaries the sleeve went past the injector o-rings just slightly so the bottom of the oring would hit the LIM when seated.

 

good info Dave, this is the exact same thought proccess i went through in my head when i was trying to figure it out.

>>More than likely they're just a little small. I would recommend using a small amount of RTV in there to seal them.


You must have been sending me brain waves on this because that is what I ended up doing earlier at the shop. I put just a film of rtv on the end and sides, just enough to seal but not enough so that it would squish out everywhere when the are inserted, i think it worked....well see :-)

 

Hehe...This would make a great write up huh , Damian ..hehe..

What can i say ... love them write up you do..hehe..

 

werd, im on it...... i already took a bunch of pics and will take more... :-) write up soon to come. :-)

 

Now if I could to THAT I'd be in business..



I'm having trouble following. Are you saying that the sleeves in your primaries are too tall and don't let your injector o-ring bottom out on the housing? Or that when you insert them they don't leave a shelf for the o-ring to rest on? Or something completely different. Maybe you can send me the brainwaves back. I apparantly still need them

 

>>I'm having trouble following. Are you saying that the sleeves in your primaries are too tall and don't let your injector o-ring bottom out on the housing?

yep, that is what im sayin. The o-ring only seals with the sleeves, it never contacts the housing.

 

man this is good stuff.. I am getting ready to install the rx7 store's fuel upgrade. Hopefully I can use your future write-up as a a guide to help me through. I am just doing 1600 2ndaries w/ the rail, fpr, etc. Just want to run 15 psi safely on the stockers... I should probably get the spacers then too or am I dealing w/ a different animal here. Thanks for all the info..G

 

hmm, i dunno on the rx7stores rail.... my stuff is all with keith's rails....but the issue of having the injectors seat properly with the LIM goes for any rail :-)