Ok i\'m stumped - can anyone help???

[Ricco_04]

Hey everyone,

I\'m changing primary injectors and it\'s proving to be a complete and utter nightmare  I will spare you the details of all the things which have gone wrong :rolleyes:

I am now in the situation where I have now had the car put back together twice and I still have a fuel leak.

I have pressure tested the fuel rails out of their positions to check for any leaks and they are fine.  I have then proceded to fit them to the engine and pressure test them again and they are still fine.  I have then re-assembled and when I crank the engine I get a fuel leak.

Im assuming that it\'s happening when the injector is opening hence why there are no leak\'s when testing as above.  So today I took it all out again, inspected it all, pressure tested it again, fitted it all back and still have the problem

I have fitted all new \'o\' rings to the injectors and where they sit in the block (12 total) I am just at a loss with what to do.  I could pull it apart and do it all again but I fear 3rd time of re-assembling will just result in the same problem.

Please does anyone have any suggestions???

[Grizzly]

Did the spacer go back properly between the rail and the Engine? Are the Diffusers ok? (plastic things under the Injetors) Not damaged or Cracked? Did you remove the old seals properly? (not any bits left in the holes?)

Also have a GOOD look at the Pulsation dampers/fuel regs on the Rails they are renound for leaking and if this was the case the fuel would run down the bottom of the rail onto the lowest point (the injectors) i sugest you have a realy good look for water marks, don\'t forget that fuel will dry quickly so it won\'t usaly be wet unless its a place the fuel collects.

Out of interst why are you changing the Primarys? are you having problems with them or are you going bigger? if they you are using diffent injectors could the seals be wrong for them?

[Ricco_04]

Did the spacer go back properly between the rail and the Engine?

Yes, sure did

Are the Diffusers ok? (plastic things under the Injetors) Not damaged or Cracked?

Diffusers where replaced along with the o ring\'s on the injectors - all brand new ones.  I was unsure they seated properly the first time so second time round I used a bit of gasket paste (the blue silicone type) to hold them in position

Did you remove the old seals properly? (not any bits left in the holes?)

The old seals came off with no problem\'s all in one go, leaving nothing behind before the new ones where installed

Out of interst why are you changing the Primarys? are you having problems with them or are you going bigger?

I\'m installing (well trying :o ) 850\'s in the primary\'s using a machined rail.

If they you are using diffent injectors could the seals be wrong for them?

That\'s interesting now I have had a think about that for a while.  The secondary injector rails have a different \'diffuser\' o ring to the primary\'s - the standard primary rail uses what just looks like a rubber band and the standard secondarys uses a thicker band with a groove in them.  

I\'m slightly confused now as should all secondary grooved \'o\' rings be used or is it that that the holes for the primary rail (in the block) are different so I am correct in using the primary \'o\' rings on the primary rail.

I hope that bit makes sence to you :o

Also have a GOOD look at the Pulsation dampers/fuel regs on the Rails they are renound for leaking and if this was the case the fuel would run down the bottom of the rail onto the lowest point (the injectors) i sugest you have a realy good look for water marks, don\'t forget that fuel will dry quickly so it won\'t usaly be wet unless its a place the fuel collects.

Sorry, I should have said I have installed a Sard FPR - using Aeroquip fittings and braded hose.  I have tapped the secondary rail to return to the FPR.  The primary rail still has this fitment (just to make sure - is this the item which looks like a top hat?)

Thanks for your help Grizzly, hope my reply make\'s sence to you

[Grizzly]

At this point you may want to ask someone like Clive or a Tuner (that has some experiance with the 850cc swap) Unfortunatly i\'ve not done it so i could\'nt tell you if the Standard Primary seals work or Not. I know there was a Bit of Discusion about the Fuel rail (does it need Machining or not??) but i\'m not too Clued up.

Worth asking some one in the Know before you go much further though.

[Ricco_04]

At this point you may want to ask someone like Clive or a Tuner (that has some experiance with the 850cc swap) Unfortunatly i\'ve not done it so i could\'nt tell you if the Standard Primary seals work or Not. I know there was a Bit of Discusion about the Fuel rail (does it need Machining or not??) but i\'m not too Clued up.

Worth asking some one in the Know before you go much further though.

Ok fella will do - thank you for your help - at least I have a potential problem to investigate where as the last few day\'s I had a problem and no clue as to why!  Nothing worse than having something wrong and not being able to find a problem! :yes

Im pretty confident it\'s something to do with the way they sit on the block as I tested them all hooked up at base fuel pressure and not one drop - so we only get a leak when the injectors open to fire fuel so that\'s gotta mean the injector o rings are doing the job but the diffusers or the way the primary\'s sit have to be the fault.........

Thank\'s again Grizzly :wave

[Grizzly]

I\'ve just been doing a bit of reading up, Are you 100% your Rail is correctly machined?

http://www.rx7club.com/showthread.php?t=81811&highlight=850+primarys

Keep an eye on this too.

http://www.rx7club.com/showthread.php?p=6866744#post6866744

[Ricco_04]

Nice one Grizzly :Thumbs-up

I have been doing some more thinking.  The primary rail is machined on the inside and the \'o\' ring/diffuser seal is on the outside so that should be fine using the standard primary type seals.

I\'ll keep an eye on the other thread too :Thumbs-up

Man, im uber confused! :2Confused

[Ricco_04]

Gonna have it all out again and test the injectors opening using one of the links you posted above :cheers which will hopefully show something up.

If it fails im going to fit the origonal one back in  Which unfortunately needed one of the lines cutting, which is also crimped on so some carefull work should see the line off and replaced with the one i\'m using now.  So all those hours for nothing :reallymad

Then I still need to sort out what im going to use for extra fuel if the standards go back in :rolleyes: