Hey guys, I am trying to put the injectors back in. The lower ones (under the manifold) seem to be fine but the ones on top are "loose".

Here is the deal. I have been running around trying to find parts for this car and as you probably know, you walk into kragen or Pep boys and say Rotary and they start making crosses and hanging garlic around their necks.

I took my injector with me to show em what it was. They didn't have the exact part but the guy showed me some injector o-rings that were "close" I took them home and like I said the bottom ones seemed fine but after seeing the loose ones on top I am going to re-check the bottom ones.

The question is.....there is no way that they should be loose after you torque the rail down is there???

 

Yes they will rotate. If really loosy goosy, it's probably not the o'ring but the upper and lower grommets that are rock hard after several years of use. They probably leak a little air if they are rock hard. Buy new ones, upper and lower.

The injectors still will rotate, as they should be able to rotate. It's a judgmental thing. Don't let a rock hard gormmet cause a air leak and an irregular idle.

 

I replaced a grommet that goes into the intakes. Large a black that fits onto the actual stem of the injector. There is a brown thing down in the middle iron where the lowers go and there is another set of brown things that are down in the intake where the uppers go. Is that supposed to be soft as well??? The ones that are in there are really hard plastic, so I left them in there. Should they be replaced and if so what are they called??


Thanks Hailers. I appreciated your quick response.

 

The upper and lower grommets, as well as the o-rings are pretty cheap at mazdatrix.com though it will take a few days for them to ship to you unless you live close enough to go there and get them over the counter. And the grommets aren't hard plastic, they are rubber. They harden up after years of use. Yours sound like they need to be replaced.

 

Click here to see them on mazdatrix web site. As you know, each injectors gets an o-ring, an upper grommet, and a lower grommet.

http://www.mazdatrix.com/C-6.HTM

 

Also, when installing them put just a bit of motor oil on the outside of the o-rings to help make a better seal. Not sure how that works, but it's what I was told works.

 

The lower seal doesn't matter for tightness really, its the upper. The upper 0-ring should fit really snug and not loose. You should have to twist it back and forth to get it into the rail, it shouldn't be easy to do, you should have to twist it some to get it in.
Just remember that theres like 30-40psi behind that seal, and if its loose your going to start spraying fuel, causing a fire. So if you think that it can stand up to that kind of pressure, then its all good.

 

Ok. Judging by the Mazdatrix web site. I got the upper and lower gromet and small o-ring. They are on on the injector. The o-ring and upper is good and tight I don't fear it leaking, its the lower one that bothers me. shouldn't that be tight in the housing??? It actually mooves back and forth about .0005 in the intake housings."

 

No comments on the brown thing in the housings??

 

The lower grommet's purpose to me seemed more focused towards holding the injector in place. It still does seal once you tighten the fuel rails and the heat from the engine will make them expand slightly so you shouldnt have a problem.

The brown things in the housings are either the mixing plates or the air bleeds I forget. Either way if they arent broken you probably shouldnt touch them. They will crack when you try to take them out and its not cool to have broken pieces of plastic floating around in there.

 

The AIR BLEEDS are hard. You should not mess with them. Leave them alone. They cost a bundle.http://www.mazdatrix.com/c-6.htm

 

Oh.....I see now. I didn't recognize the parts from the webpage pics. they were side view and I only saw them from above. Thank you very much. I'll leave them alone and see if fuel comes spewing out when I go to start it......I'll post the results

 

Here's a tip. Dont start up your car. Put the injectors in and tighten the fuel rails down. Do not put the UIM manifold back on until you use the fuel pump jumper to pressurize the fuel system to check for leaks. This way you wont have to keep taking off your UIM to find the leak and you will be able to clearly see where it is coming from.

 

Ouch, for what that place charges for the parts...You can get the injector cleaned and flowed with new parts too.
I believe I will make up some complete seal kits for the RX7's and sell them for a reasonable price. Hate to see folks taken advantage of.

Gordon
WitchHunter Performance
Fuel injector cleaning & flow testing service

 

NAPA has a kit for this pretty cheap as i remember.

 

I sell the injector o-rings for 21.00 shipped. You get 4 sets. all o-rings/gromets and pintle caps.. 2-3 day shipping

 

I have purchased the above mentioned parts from Mazdatrix for a S5 TII. I have just had the engine rebuilt and engine bay repainted (and numerous of other things) done and wanted to purchase new parts in the belief this would be most cost effective in the long run.

I purchased 2 denso 550cc pri and 2 denso 720cc sec, along with the correct injector clips from RX7.com

I purchased 4 10w 10ohm resistors (white blcoks) from radio shack.

The injector bleeds pictured from left to right are primary lower - primary upper - secondaries. Also ppctured is the cspacer for the primary fuel rail.

Thanx

Micihael

 

Here is an update. I went a bought the lower gromet from Mazda. Part number N350-13-257. It was $11. I did put them in and it is a tighter fit. The injectors rotate or twist but they don't wobble in the base as I described earlier.

Yes parts stores usually carry the kits for a reasonable price. The kits I bought were only $12 for four of them. They did not have the correct kit for me on a Sunday so we matched up another kit and that lead to the problems. The o-ring was right, the upper grommet was right, the lower grommet was really close but just too small. The Mazda one made me feel much more comfortable as it fits much more snug.

Thanks for all your help. I know Shade treeing the kits lead to unnecassary stress but maybe this thread will help somebody in the future.