So the other day, i was running the car with the hood open and I noticed something about the smell. I recognized it right away what it was....gas. My friend, who is a technician, was there with me. He told me it looks like a intake leak. Is that possible? Motor is n/a with 145k.

 

pulsation dampener, search around the forum and ye shall find horrifying pics. fix it asap...

 

First thing you should be concerned about if you smell gasoline fumes strongly is your fuel pulsation damper (FPD). It is on the secondary fuel rail right under the throttle body. It is a plastic bulb that tends to leak in higher mileage cars. Look underneath it for raw gasoline and if you see some, DO NOT drive the car.

If the smell of gasoline is faint it might be old fuel lines that are venting a bit or leaky injectors, right off the top of my head.

 

Pulsation Dampener...horrible things happen if you don't fix it.

 

Thanks for the advice guys. Glad I asked right away. By the way does anyone have a pic of what the (FPD) looks like? That would help me out alot. One more thing, can I find a replacement at the local autoparts stores ?

 

It's a Mazda only part.
You need to get it from a dealer who sells Mazda OEM parts.


-Ted

 

your car is going to explode if you dont fix that


have a nice day.

 

This view of the PD is from the driver's side of an S4 TII, with the upper intake manifold removed.

 

Thanks for the very helpful advice guys. Gonna look at it right away today. Thanks for posting.

 

Karack is right

 

No big deal, but in the picture I mis-named the primary fuel rail as the "lower" fuel rail. I have no idea why!?

 

FIX IT!!! FIX IT BEFORE YOUR CAR BURNS DOWN!!!!

read about the Marren Pulsation Dampner retrofit in the archvie and do that. It's like $200.00 for all the parts and is much more reliable. the stock PD is $130.00 about. spend the extra $70 and get a PD that when it fails, won't spew fuel on your housings.

Peace.

 

yeah, mine leaked......and burned a WEEK after I took it to Mazda and told them I smelled gas and needed them to check it out. Guess they missed that one.....

 

Sorry to bring this topic back, but what about Rotary Resurrection's directions to fix it?

http://www.rotaryresurrection.com/ro...pulsation.html

Wouldn't that be ok to do instead of using another PD?

 

Some people will tell you it is okay to use a bolt to replace a leaking PD.

I feel Mazda would not have put the PD on there if it was not needed. Without a PD there is the very real potential to damage the engine from harmonics in the fuel rail.

So, a bolt is a better than a leaking PD, but should be considered a band aid, and not a real fix.

 

Or just replace the 15+ year old unit with a new one, and it should last beyond the life of the car. *shrug*

Back onto the original poster's question, there *are* a few other things in the engine bay that can cause a raw gas leak. Leaking injector o-rings, a failed purge valve on the charcoal canister (or a removed charcoal canister), and some other things.

The safest way to troubleshoot a fuel leak is to pressurize the system with a cold engine. If you turn the ignition on (but don't start the car), and jumper the fuel pump test connector (yellow, passenger's side, near the airbox, 2-connector), the fuel pump will turn on and pressurize the fuel system. You can now search for leaks on a cold engine where there's a very low chance of anything actually igniting. Keep a fire extinguisher handy, just in case.

-=Russ=-

 

A MINOR upgrade would be the stock S5 primary fuel rail.

The S5 FPD is inside the rail and I see NO external place for it to leak in the even of a failure.

So if it does fail you'll never really know but it won't leak outside your engine and cause a huge engine fire.

I do have a stock S4 FPD sitting in my garage some where. I removed it from a junk yard NA.
The screw inside the FPD is still intact which is a very good sign that it's a good/usable FPD.
Commonly the screw will back itself out of the bad FPD's. Both of my previous NA's had them backed out when I replaced them.

 

So it is true that the S5 primary fuel rail will not leak fuel due to a FPD failure?

Hmm, makes me wanna stick one on my car. Will it bolt striaght up to my 88 TII?

 

Yes. I am mixing S4 and S5 fuel systems(S4 secondary/S5 primary). They work fine.

I looked at my S5 primarty and I see no way the fuel can leak externally.
The FPD is internal. Of course it's still probably it will fail and leak but it would leak internally.


The only disadvantage is that they do not have threaded ends so if you want to upgrade to your own fuel system you have to buy S4 pieces.
An example is that I have a S4 secondary rail which I have SS lines to an Aeromotive FPR.
S5 rails are all welded together and can't be easily modified.

 

NO that is radically incorrect.

If you look at the S5 and S6 PDs, you'll see a little rubber stopper at one end. If this stopper breaks it will leak just like if a screw fell out on a S3 and S4 PD.

The S5 PD is not in the rail, just welded to the end of the rail. If it fails, gas will spray out, not just dribble out like a S4 with its cap does. In addition to replace the S5 PD (which just like a S4 PD should be replaced every 100k miles or 10 years (which ever comes first) you must replace the whole fuel rail, not just the PD like a S3 or S4 PD for a much higher cost.

I have personally seem more S5 and S6 PD's leak than S4's; and when they leak they spray

 

No that is incorrect. They leak worse when the S5 and S6 PDs fail and cost considerbly more to replace.

 

About what do I need to do in order to get acces to the FPD. remove UIM ? That about it ?

 

You know, if you take the screw out of the S4 pulsation damper, it will NOT leak. When I first got my car and removed the injectors for cleaning, the PD in my rail had the screw bouncing around inside the plastic cap. I took the cap off and there was no fuel, or no smell of fuel, and no leaking from when the car was actually running. I put the screw back in about halfway and am still using the damper. I have had no leaks.
Either way, its not something im gonna chance, a new one is on the way. Just FYI tho, if the screw is out it does not mean the damper is toast.

 

Next time I take the UIM off I'll have to check that out. I don't remember seeing a hole at all on my S5. Although mine was a Jspec and has oddities on it.

 

understand this is a clear warning - don't let the same that happened to me, happen to you.


15$ repair?


or

1500$ repair?