Mahjik

iTrader: (1)

Test the fuel system like my link several posts above. If that tests out ok, then check the grommets. I've seen the grommets get pushed down into the injector hole instead of having the rail slide into the place on the primaries.

TypeFD

iTrader: (1)

Alright, so the last theory is going right out of the window... the insulators are not present where I thought they did, they're seated between the rail and the engine block. Crap.

I still can't track down where it's coming from. I've bridged F/P and GND countless times and I can't replicate the leak. I removed the injectors and bridged the F/P and it's spraying in there with what seems to an ample amount of fuel.

One thing I thought weird... I didn't relieve the fuel pressure when I removed the injector and when I did that, the fuel system was not pressurized - in fact, the injector came out as if I did relieve the fuel pressure. But if anything, the lack of fuel pressure would not contribute to the fuel leak... maybe it's nothing.

I'm going to reassemble everything and see if I can get the fuel leak replicated again with motor running... at this point I'm at a loss. It feels almost as if may be too much fuel is being delivered to the injectors under too much pressure and they're spitting it out through the top and via the connectors.

There is definitely a leak there, I saw the small puddle and there is obvious residue. The hunt continues...

Mahjik

iTrader: (1)

If you removed the fuel rail, then did the F/P - GND test (like in my link), there should be no fuel coming out of the injectors. The injectors should be off, but the fuel pump pressuring the lines to see if any fuel is leaking anywhere.

TypeFD

iTrader: (1)

Thanks for chiming in mate, I did go over the information you referenced extensively. I was sure to check the o-rings when I pulled the injectors, which looked good and still like-new condition.

I should have taken the picture of this... but I believe the fuel is coming up through the connectors as I found fuel inside the connectors after initially pulling it all off. Then, it was leaking down on the injector and looking like as if the fuel was coming through the o-ring, between the rail and the injector itself.

In any case, I'll try replicating the issue and taking some pics. I can't do jack unless I can get it to leak again right now ;(

Thanks again...

TypeFD

iTrader: (1)

Correct... and no leaking was present. I didn't even smell any fuel!

BTW, just so it's clear: in that case, I pulled the injectors out and did the GND-F/P test to see if the fuel was even delivered as I was seeing no leak at that time I was attempting to replicate it - and thought that may be it was a different problem. But the fuel was getting to the injectors so that wasn't the problem.

Mahjik

iTrader: (1)

Ok, this statement is what's confusing:

At this point, I would recommend just reconditioning your fuel system. New o-rings, grommets, injector cleaning, etc... I posted a link to that earlier in your thread:

https://www.rx7club.com/3rd-gen-archives-73/injector-removal-reconditioning-replacement-232603/

If the parts have been on there for 70k+ miles, it's probably time to have some maintenance done there anyways.

TypeFD

iTrader: (1)

Whoa whoa whoa dogg, I just got it serviced, the injectors were serviced, new o-rings, grommets, insulators, diffusers, FPD, etc... check out the initial posts (I know, it's a lot of reading).

Mahjik

iTrader: (1)

How long did you wait before you installed the injectors after the cleaning? Are you using the o-rings from the injector cleaning service or OEM o-rings?

TypeFD

iTrader: (1)

Put them in right away, using o-ring that came with the injectors after service. They were green. I believe Auto RnD did the job... there was a group by on the forum they were running a special.

Mahjik

iTrader: (1)

I've had issues with non-OEM o-rings. It's possible that your leak requires more load on the system to appear. It's safe to assume that you do have a problem if you have fuel pooling so regardless of when the system was reconditioned. Something either wasn't done properly or you just have bad/damaged injectors.

If it's the injectors, you'll need an injector service company to check/test them. If it's just part of the fuel system, then that's something you can address yourself.

From what I've read, you have two options to go with from here:

1. Purchase OEM o-rings and see if those provide a better seal
2. Send the injectors to an injector company for checking & testing

TypeFD

iTrader: (1)

I think I've got something!

Now I'm still following this lead but even if that's not the source it's still worth bringing up for whoever tries to troubleshoot similar issues.

Right, so combing over the Workshop Manual I noticed that I'm missing a washer on my Fuel Thermosensor.

Fuel thermosensor is sitting on the secondary rail and when I was getting to put the ACV back on (yeah, the PITA nut underneath) I took the Fuel Thermosensor off for more room to get my hands under the ACV. Well, ofcourse the fuel came out and one thing I noticed is that the "flooding" pattern was very similar, fuel was all over the primaries and then there was a puddle underneath. Even more interesting, there was a puddle of fuel accumulated at the rear of that area... which I was puzzle before who the fuel could've gotten there if it was coming off the injectors since there it's sitting at a higher elevation. Now if it is a Fuel Thermosensor then the fuel could've easily ran down the secondary rail to the rear and dripped there!

Right, so I'm throwing the washer on, soaking up the area with a rag and going to give it a week to make sure the remaining residue is gone.

I'll report back as soon as I have something.

alexdimen

iTrader: (13)

My thermosensor threads tore up the o-ring when i removed the sensor from the fuel rail to clean the rail during the rebuild. They are sharp machined brass threads.

Mahjik

iTrader: (1)

Hopefully that's your problem. However the F/P - GND test is usually able to make that leak if there's a problem with the washer. Good luck!

Sometimes just taking things apart and putting them back a 2nd time fixes the issue (i.e. you didn't do something 'exactly' right the first time but you took more care the 2nd time).

TypeFD

iTrader: (1)

Well, I've got some good news and some bad news...

Bad news first - after installing a copper washer on the thermosensor I observed no leaking... Unfortunately, I simultaneously observed fuel saturating the primary rail without an apparent source of the leak... again.

Good news - after reassembling everything, getting the motor warmed up... AND... turning the motor off I was finally able to find the source this time. The fuel is coming from the primary injectors - not through the connector, but right from where it sits in the rail - indicative of a bad seal by the existing o-rings.

It was interesting - while the engine was running I saw the area around primaries become evenly saturated with fuel but not strong enough to detect source or even excessive concentration of fuel in any particular area. Only once I turned the motor off, I could instantly see the fuel squirting out of the fuel rail from under the top of the injectors. I also heard a "percolating" sound?! Weird...

I'll call Malloy and order a new set of OEM o-rings for the injectors... Watch for my report next weekend!

Thanks again to all you guys chiming in.

alexdimen

iTrader: (13)

I thought the sensor on the secondary rail was an o-ring seal...

gripp2maxx

been down this roads with two fd's fun huh..................a+ on your attn detail!!

nguybao

iTrader: (6)

That's some serious long term troubleshooting! I did my fuel system last month since I was taking everything apart for inspections and maintenance. I sent my injectors to RC Engineering for flow testing and balancing. They replaced the o-rings and I installed new insulators. Haven't had any leaks so far, but when I was seating everything, I used a small mirror and went real slow to check that everything was seating properly.
Some people posted they had problems with RC so I guess I just have to see. I'm using the stock fuel system and sequential twins.

TypeFD

iTrader: (1)

*****! Well now I'm pissed... So I spent $50 bucks in getting blasted oem orings from malloy then 4 hours outside putting the ***** and today's test drive revealed.... the same damn leak. It's reeking fuel under there and prominent puddle of gas, the only dry areas are actual connectors on the primary injectors. Everything else is soaked.

I have no frakking clue what to do next. Anyone looking to buy an FD?

Okie-RX7

iTrader: (1)

Is the primary rail damaged, like a small burr or anything that could be damaging the o-rings. I only ask because I am in the middle of the same project myself right now. I had a leaking FPD, and in the process of replacing it, I have also replaced the diffusers and grommets. Installed it all and ran the fuel pump and have a similar leak from the primary injectors, mine appeared to just be slowly leaking from the top of the injector by the rail, not from the connector, so I just ordered new injector o-rings, hopefuly it's only that. Have you coinsidered trying a new primary rail, they can be purchased fairly cheap on ebay, Good luck with it.

TypeFD

iTrader: (1)

Okie-RX7 - it couldn't be the rail or the insulators as the fuel appears to be on top of the rail. Insulators would lead to a leak underneath the rail.

I carefully inspected the whole area and definitely don't see fuel in the injector connectors either, so it's either leaking somewhere between the injector and rail (sealing) or maybe it's coming out of the very top of the injector, right there through the center. Anyone had an injector leak from that location?

Another theory I've heard was that may be fuel pressure regulator malfunction is causing a high fuel pressure buildup causing injectors to leak... anyone can comment on this?

Thanks again guys.

Mahjik

iTrader: (1)

Did you do the test I showed in the link earlier by extending the fuel lines to test with the rails exposed?

TypeFD

iTrader: (1)

I didn't pull it out like you did. I didn't think that was necessary at the time as I wasn't even able to replicate the leak. I might have to do it if this continues.

STATUS UPDATE:
I was so pissed since my last post that I just left it alone and worked on my bike instead. I took the car to work Monday and Tuesday and today, after work, I decided to take another glance and see how things are looking under the hood.

Long story short I think I'm loosing my friggin' mind.. I can't find the leak anywhere. I tried grounding the F/P, starting the car and warming it up, taking couple of hard runs... I can smell the fuel a little bit still but I can't find any wet residue anywhere. Maybe I'm just getting high on gas...

I'm going to lay off this problem for a week or so and may be watch for the leak, in the meantime, can someone get me some input on a failing pressure regulator? Symptoms? Outcome? etc... Is it possible that my injectors are fine but being subjected to too much pressure?

bond007

Yes. I had a FD I worked on with a fuel smell and it turned out to that the primary injector was leaking out of the top, through the plastic. It was the strangest fuel leak that I had ever seen!

Anyhow, I contacted the various injector service facilities and described the problem and was told that it was not repairable (at the time, this was probably 7-8 years ago, I doubt that this has changed recently, though). The owner bought a new primary injector and that was that.

You can VERY, VERY carefully pressurize the fuel rail without the metal "cap" that holds the injectors in place to look for this leak, provided you hold the injectors down with safety-wire or are willing to hold them in with your hands (fully understand though, the risks, i.e. fuel under pressure, fire hazard etc.). It is not as dangerous as one might think, as you have to "jury rig" top-feed injectors similarly to leak-test them while not mounted to the intake manifold on a FC or Miata. When I removed the cap, the fuel leak was VERY apparent.

Dab the corner of a white paper towel against the suspected leak area and you will easily see minor fuel leaks wicking onto the paper towel (I stole this test methodology from my EMT training, the "halo" test where you do a test for cerebrospinal fluid, to give credit where credit is due).

Easy-peasy. Run the fuel pump test like before. Take a mity-vac and apply pressure to the FPR, say, 15 PSI or so and that will increase the fuel pressure to the levels seen under boost. This would not accounts for vibration or heat inducing the leak, though. To test the FPR, you need a F/P gauge but I doubt that it is the problem if you can find an external leak.

--Ashraf

GreatShamanGT

iTrader: (9)

Didn't want to start a new thread, when Witch Hunter sends the injectors back, do they label which ones are which? Like which ones flow xxxx amt? I'm thinking about going through theem to have my injectors cleaned, but I'm a bit worried about signing a sheet with my credit card number, etc on it, lol.

pomanferrari

iTrader: (1)

Don't mind saying this: told you so ... the injectors are structurally defective ... no rebuild will save them. You'll have to get new injectors.


Make sure you have the insulators between the tip of the injector and the fuel rail. I chased this problem for over 5 years and it turned out that the Mazda dealer monkey didn't install them.