I was doing some surfing and searching the forums about possible fuel leaks. I have a 1994 RX7 with 28,000 miles that is stock everything.

I smell fuel after I've driven my car when I walk by it. I see no fuel leaking on the ground and I THINK that the smell is from under the hood.

After my surfing I know that the 2nd gens had a fuel dampner that would leak fuel. I wondering if anyone knows any links that I could read that might be related to this problem.

Are there any common problems I should be looking for? I'm not very good at surfing so if anyone has a link for FAQ's about it I would most appreciate it.

After much debate I've decided to keep this car and fix some problems. I just read and performed the Odometer FAQ last night and it worked like a charm. Thanks to all for the GREAT information.

Thanks!

 

The 3rd gen also has a very faulty FPD. I just replaced mine, and I know many people replace them pretty often. It usually starts to crack and leak if the car has been sitting for a while. I would start with that, check your fuel injectors and fuel lines.

 

Have a look at this forum thread.

 

I bought my `93 FD in 2010 and the first thing I did was replace all vacuum hoses and check all the fuel lines.

I smelled a gas leak and found a short line close by the fuel rail to be splitting. It wasn't leaking enough to reach the floor but you could definitely smell it while driving.

Very lucky that yours has such low miles. My car is a little over 95,000 miles. Going to do a rebuild within the next month though. Rather feel safe than go kaboom.

 

THanks for all of the insight.

I want to leave my car stock but I am also for getting rid of complexity I don't need. It's a tough decision to get rid of the dampner if that is where the fuel leak is from.

Thank yo for the link too!

 

I'd say keep it if your staying stock. Mazda put the dampener there for a reason.

 

There's a lot of debate on that subject. A lot of modified FD's eliminate the FPD (me included). You can purchase a fuel pulsation dampener from Mazda, or purchase the recall kit, though I can't remember exactly what is included.

As much of a PITA as it is, I wouldn't sit on the problem for too long there has been a number of RX-7's burn to the ground from FPD leaks
-Dan

 

As much of a PITA as it is, I wouldn't sit on the problem for too long there has been a number of RX-7's burn to the ground from FPD leaks
-Dan[/QUOTE]

Holy CRAP!!! I will use caution on the way to the garage!

 

I have not driven my car in about a week and today I noticed a puddle of fuel under the vehicle!!!!!

It's dripping off of the bottom of the transmission. I have no idea where it is from. I can see the rubber lines going to fuel rail but I can't see the injectors and rail itself. The rubber lines are not leaking.

I opened the fuel tank and there seemed to be a lot of fuel pressure in the tank. It made a big hiss when I unscrewed it. I left it off in hopes that the pressure is pushing it of the lines somewhere until I can find it and fix it. The fuel tank is ful,l I just filled it up right before I parked it BTW.

Can this still be the fuel dampner? I just assumed that it would only leak when the vehicle is running.

Am I going to explode if I drive it to the garage? Think I'll have it towed.

 

Don't drive it! It's less likely the damper but still possible. I would say a line somewhere is leaking

 

Just an FYI so you can budget for it if u decide to keep it:
I replaced my FPD in 2008 with an OEM unit from Ray at Malloy Mazda...

Part# N3A2-20-180
Price (in 2008): $110

Also, if you have fuel dripping from the tranny, then your leak is on the engine side of the fuel system. Pull your upper intake manifold and find the leak. Even though you haven't driven your car in a week, there is still fuel in the lines which can leak out without being pressurized...assuming something has failed.....which it has.

Steve

 

Ok....

I will pull off the intake Monday. I will replace fuel lines and vacuum lines. I also noticed a leak that I suspect is from the oil metering lines. I will repair both at the same time. Is there a vacuum harness that I replace or is it all separate pieces of hose?

It seems that all kinds of rubber parts have been attacked eventhough my car only has 28,000 miles on it. Must be age. I also have two A/c orings leaking too. I will reseal the a/c system too.

The rear contral arm bushings are bad too. I think you 7 guys call it a pillow ball coupling. Sigh... looks like I will be working on the damn car all day!

Thanks so much!!

 

Welcome to fd ownership lol. A lot of money goes to fixing 20 year old parts.

 

Age plus extremely high under-hood temperature. If you replace the rubber vacuum hoses (they may have turned to hard plastic in some areas), IMHO Viton is the way to go, although many here recommend silicone. (You might want to read this old report on tests of various types of hose material.)

Lowering coolant temperature with the FC fan control thermosensor (97°C vs. FD's 107°C) will help.

Replacing the OEM pre-catalytic converter with an insulated downpipe will also help.

 

I had a leak from my secondary rail. A grommet wore out and was spraying out so I replaced everything fuel related to be on the safe side. To me it's worth replacing everything from because you are already torn that far into the engine so might as well so you don't burn on it later down the road

 

I pulled off the upper intake today and found my fuel leak. The fpd is leaking. The fpr looks dry. I ordered a new fpd from Mazdas as well as gaskets and all new injector insulators. The vacuum lines all still feel like rubber but I will replace most of them anyway.

There are a TONS of vacuum operated switches under the upper intake. I was surprised at the complexity of it all. I took a bunch of photographs while I took it apart to make sure I get them all back in the correct orientation.

The parts will arrive on Thursday.

I have a question though. The oil metering lines look intact and I gave them several good tugs and they feel ok. Do they fail often? Should I be replacing them? My mechanic says to leave them alone but for added measure I should be dumping in two cycle oil into my fuel. Should I be doing both!?!??


THanks!!!

 

I would approach the oil metering lines in this way....they are 20+ year old plastic lines that have been exposed to repetitive heat cycles (although in your low mileage car, less cycles than most). I have seen a lot of members replace them with steel braided lines for piece of mind, but it is your decision. As far as adding 2-cycle oil to your fuel, there is a lot to be found on the subject in the FAQ's. Adding oil with the OMP still in place will not hurt anything. For me, I have deleted my OMP and pre-mix with every fill up.

With that being said, and what I have learned over the years, I would have started pre-mixing the day I got my 7. Our engines are basically two-stroke engines. The OMP drips 4-stroke oil into the combustion chambers (during the intake cycle prior to compression) to provide lubrication between the housings and apex seals. This is not what 4-stroke oil was formulated to do....two-stroke oil, on the other hand, is. You will probably ask "if this is correct, then why didn't Mazda do it?" The answer...they wouldn't sell any cars if the owners had to add oil to the gas like an outboard motor boat. And they are right. So they came up with the OMP as a solution. Do some searching. There is great info on the subject from some very experienced club members.

Steve