Leaky Injector related to other problems?
 

Just had the scariest ride home from school after smelling fuel and noticing that injector 4 (front one, cant remember if thats 1 or 4) is seeping fuel! I cant tell if its both the top and bottom seal or just the top one and dripping down but none of the others seem to be leaking at all. I'm waiting for the engine to cool down so I can take the fuel rail off and see wtf is up with this shit.

Yesterday my car started making a boost leak type whistling sound while in boost. Could these be related? I dont have an air compressor anymore and dont have a bike pump to do a boost leak test but all my couplers are tight and in good shape.

I've also been battling a persistent high idle issue. Could a leaky injector cause a vacuum leak somehow that could be causing this as well? I dont see how it could, but I swear I remember reading someone's post about a vacuum/boost leak being related to a leaky injector.

Ever since the Autox I went to last weekend my car has been developing issue after issue. Its really discouraging and makes me really uncomfortable taking it on a long trip.

Well if its not sealing properly at the bottom too that will cause a vacuum/boost leak. Do you have the vacuum seal spacer thing in place at the bottom? Those also get very hard and don't seal well when they age.

Well, from memory I think the round seal thing at the bottom was different than the one on the stock injectors. I installed whatever injector rehab included with the injectors. The engine still isn't quite cool enough for me to take it all apart and inspect.

Yes. The lower seal is leaking under boost.

Yes. The lower seal is leaking un-metered air at idle.

These two correspond perfectly.

Well all the upper seals were cracking despite being 2 months old. I swapped out the seals with the old stockers and now the previous leaking injector is fine but inj 3 is straight up spraying out of the upper seal. Done working on it for the day, will try and figure something out tomorrow.

Do yourself a favor and go get 4 new kits from OReillys (if they can actually order you the right part, fuckin newbs) for a total of $28, and not have to worry about that shit for a while. My stock ones were in pretty bad shape, and the RX7 ones were worse.

These were brand new from injector rehab. How do I know they aren't similar or the same part i'd get from the local parts store?

Oh yeah, I had read that and still blabbed on. Good point. Kinda strange they'd go south. In that case, user error. :fawk: jk.


Seriously though, I've been reading about a lot of leaky injectors. I'd like to know how the guys that don't have problems install their injectors/fuel rail.

When I initially installed my cleaned injectors from injector rehab I had to use my original bottom injector seal (heat insulator)-the ones that actually fit into the head because this wasn't included with my injectors (you sure they sent you the correct one?). Of course they leaked (air) like crazy when I put them under pressure-they didn't leak any fuel even though they were cracked all to hell. So I got new ones from Advance Auto and no leaks now. There are three seals per injector-you are using all new ones for all three? If so then I don't see why you would have leaks.

A tip for those who may not know - cover the o-rings in vaseline before applying. This will keep the rubber slick enough that it likely won't get pinched during installation, and gasoline will wash the vaseline away on contact.

See? Now that's what I'm talking about. Awesomeness...in a jar...of vaseline.

Thanks man.

Yeah, i use the Vas too. some say not to because it can deteriorate the rubber but I have never had a leaking o-ring yet. My brand new injectors from Deatchwerks came with a lil tube of lubricant.

So can someone clarify something for me?

What is the difference between the rubber giant o-ring that came with my injectors from I.R. and the hard plastic thingy that the stock injectors had on the bottom? I checked the stock plastic ring for fit on the rx-7 injectors and it didn't fit over the pintle cap.

I've done this shit so many times on several cars and never had a leaky injector before. I guess there is a first time for everything. Next time i'll use the beatin lube like you guys.

That wasn't plastic. It's rubber that got hard from years of high heat

As far as actual sealing into the fuel rail, does the little rubber boot thing actually do any sealing? Thats what was cracked on all of my new injector seals but i'm not so sure at this point that those things actually play any part in the sealing.

I received my injectors from begi, did not come with the lower sealing rings. I re-used the old ones that were with the stock injectors.... So, a few weeks later, chased an air leak to a cracked lower o-ring. I bought new ones based on Stephanie's advice and things are fine now. I have the part number from NAPA if you want that: part number 2-12076, that's for my 550 cc injectors on 2002 miata for reference... I don't know if that's what you need. I bought 4 boxes and changed all of the o-rings on the 4 injectors.

Thanks for the advice. I'll see how things hold up moving forward. The fuel pissing out of inj 3 ended up being an o-ring I messed up when re-installing everything.

After a short drive I think the high pitched under boost whistling noise is gone but my idle is the same. 1100rpms and never goes any lower. The MS seems to be sending the right signals but the idle valve isn't getting them. No change when I unplug the harness at the idle valve itself. I'm 99% of the way to giving up on the idle and continuing to live with it.

I really doubt its the lower seals causing all this. They are very snug and still rubbery and brand new. They do, however, look quite different from the stock ones. They are smooth and not textured like the stock ones.

my TB had a cracked gasket for a while, causing my to idle aroune 1100 rpm as well. Replaced that and problem solved. Maybe check there? Sounds like a leak somewhere, im assuming you have messed with the idle screw?

Oh yes, messed with the screw, gasket is fine.

The high pitched whistle is still there when I hit boost. I hope its not my bov.

It could be the same point that i'm leaking vacuum could it not? By my thinking, a vac leak = boost leak under pressure.

This is a long shot...

But there is a little nipple at the back of the manifold on the #4 runner that may need a new cap on it.


I chased down a horrid fuckin' vacuum leak (which would have turned into a boost leak) for WEEKS, and saw that crap when changing the clutch. That is the single best feeling I've ever had putting on a 25cent piece of rubber next to strapping on a Magnum sized condom with your girlfriend the other night.