OK I WAS READING ABOUT IT ONE DAY AND I GO LOOK AT MINE A WEEK LATER AND THE DAM THING IS LEAKING. CANT I JUST SUPER GLUE IT. OR DO I HAVE TO BUY THE DAM PART FROM THE DEALERSHIP. IS IT CALLED THE PULSATION DAMPER. OR CAN I GET IT FROM AN AUTOPARTS STORE. ABOUT HOW MUCH DOES IT COST?

 

Do NOT Drive Your Car Until It Is Fixed!!!

http://www.mazdatrix.com/c-pulsation.htm

 

What is this and what are the signs of it being bad? Thanks.

 

Well what are the signs of it going bad?

 

Um, hey guys, you see those underlined letters in my first post? Move your mouse pointer over them, and then press down the left mouse button when they turn blue. Pretty cool, eh? :p

 

There really is no way to know that it is going bad. The only real sigh of it being bad would be to smell gas. The pulsation dampener smooths out the pulse from the fuel pump. Im pretty sure it is a dealer only part.

 

Here is an animation of the 84-88 and 89+ pulsation dampers:

Pulsation Damper Animation

Inside, there is a rubber diaphragm that moves in and out with the puslation in the fuel line pressure (caused by the fuel injectors). Early PDs had the screw which is often blamed on the failure. Not entirely true. The screw, itself, only serves to limit the diaphragm travel, so it doesn't slap back against the fuel rail pickup. If the screw comes loose, or falls out, the PD does not neccessarily leak. Over time, however, the overtravel will cause the diaphragm to tear (which it might still do, even with the screw in tight). As you can see in the animation, the screw actually moves in and out with the diaphragm, so you can't just JB Weld it in place without disabling the PD. Later PDs got rid of the screw and simply made the fuel rail pickup larger with little notches, so the diaphragm can slap against it with out causing problems. Without the screw, a draphram failure is still possible, but the rubber plug prevents heaps of fuel from pouring out of the PD and onto the hot exhaust manifold below (poof!). Failures of the later type are indicated by a smell of fuel, but earlier ones spew raw fuel out with amazing effectiveness (ask me how I know).

What to do? Preventive maintenance for the older type is to put silicone sealer around the head of the screw, so it can move in and out but not come loose. This might help slow a fuel leak, but no promises. You could also replace the old type with the newer type, but then you'll need new fuel rails, as the PD is integrated into them. A third option is to simply disable the PD. Several have done so with no reported ill effects, but I cannot assure you it is perfectly safe (this might limit the life of the fuel pump, for example). What I can tell you is that no PD is better than a leaking PD! You can replace the PD with a M12 x1.25 Banjo bolt.

 

I just went to a junkyard today to get a primary fuel rail for my 87.. The screw was already out on it, and I was hoping I could find an 89-91 to replace it with. The 89-91's are made differentl/y so they can't leak. Bastards wanted 50$ for an 87 one! I figure I'll just find someone on the board or something with an 89+ to sell..

Anyway, at the junkyard, they had 3 rx7's. One was REAL good looking 87 gxl. The other two: a gxl and a 'vert, BOTH with PD failures, and engine fires. It's a very, very scary sight. The other gxl got so hot, the secondary fuel rail (which is METAL) was partially melted. The radiator, melted. The wiring harness was a few strands of copper. Hood, deformed from the heat. You do NOT want to risk that.

-Tesla

 

What I am gettin here is that when the PD is bad you will know because gasoline will leak on the engine. Any other way to tell? Thanks.

 

Make sure you fix the PD. I didn't know mine had a problem until it was too late. My first Anniversary Edition went on fire on new year's day. It's not a nice thing to watch your car go on fire. I ended up finding another Anniversay Edition anyway so I'm happy.

The engine fire I had caused moderate damage. Only ehe engine bay was effected, but many parts were melted including the Intercooler. I've seen some people that had a mild fire and the only had to replace a few parts I've also seen some wild damage to one or two FC's where the fire spread into the passenger compartment and melted the dashboard, windshield, and front right tire. You really have to be careful. You don't want this to be your car:

From Hero...


To Zero.

 

Had this exact thing happen to me. Kept smelling gas, but couldn't fgure out from where. Driving home, saw smoke, pulled over and opened hood. Fresh air to the fire was not a good thing to provide.

Fortunately, I carry a fire extinguisher in my car and got it out before too much damage. After settling with the insurance, had to replace the entire wire harness, 2 injectors, fiber heat shield on underside of hood, fuel rail, and NEW Pulsation Damper and a few other odds and ends. Good as new, but I got lucky.

Don't EVEN think about replacing with used. Not that hard to replace. Wish I'd read this post beforehand.