Paul Hillenaar

Thanks to this forum for saving another RX-7 from burning up under the hood.
My brother recently bought a 91 RX-7 convertible ( 160 K miles ) from a guy in Las Vegas and drove it back to Ontario Canada. This car had a new engine installed only about 4 years ago and had less than 30 K on the new engine.
Just last week my brother was pulling out of the garage with the engine still cold and he smelled gas fumes big time. He shut it down and called me. I immediately suspected the Pulsation Damper after reading so much about it here on this site.

Sure enough after removing the alternator and a quick start up indicated fuel spraying out of the small opening of the Pulsation Damper on the main fuel rail which could be barely seen under all of the intake manifold. The fuel sprays all over the top of the block and into the path of the alternator towards the front of the engine.

It took 4 hours of work to remove all of the intake manifold and associated parts and hoses to get at the primary fuel rail and put it all back together. The cost for the fuel rail with the PD was about 200 dollars from the local dealer.
At the same time we replaced all of the vacuum hoses and fuel lines with new ones. It was amazing how brittle the vacuum hoses were. They literally broke apart like peanut brittle.
The dealer that installed the new engine did not replace the vacuum hoses nor did they install a new fuel rail with PD.
For those that want to do it yourself a few words of advice. Take your time and remember where all of those hoses and parts go. Replace all of the vacuum hoses and fuel lines. Replace the o rings on the 4 fuel injectors. Replace the intake manifold gasket as well as the gasket on the BAC valve. Be very careful trying to unplug the fuel injector connection plugs.

So for all of you that think 1989-1991 S5 cars are safe unlike the early models you might want to rethink about not replacing the PD. The design might be new but the location is a sure recipe for disaster if the PD goes without much warning.
Had this happened after the car was driven and the engine was hot the car would be toast.

I have an 1989 model with fewer miles and am planning on doing it very soon.

I am also planning on filing a complaint with both the Canadian and US government agencies to insist that Mazda recall all of our 7's to prevent future fires and possible injury or death to owners and their families.

Sorry for the long post but I thought it important for everyone.
I appreciate all of the members posts over the years which has helped me enjoy and maintain my 7.
Hopefully this post will help someone others.

Brody8877

iTrader: (10)

wow nice saved. But anyways, i dont think the PD is a defective design, just over time it gets worn out and failed, just like every other mechanical parts.

drago86

It's not a defective design beause it wears out, It's a defective design because It was not engineered with the ideal that it could fail in mind, thus there are no fail-safes when it does fail. A simple relocation of it would have probably been enough. Cars bursting into flames when a part wears out is a defective design.

Black91n/a

Just this past weekend I replaced my PD/fuel rail. I cut apart the old one to see what sort of condition it was in and it seemed to be very good. The rubber was in good condition, was very pliable and didn't seem like it would have failed anytime soon. The car has a Mazda reman engine in it with 40 000 km's on it (nearly 190 000 km on the chassis). I'm not sure if they replaced it or not when it was rebuilt, but it's not on the invoice, so it would have had to come on the engine.

The advice on replacing all the injector seals is a good one.

I have another piece of advice, make sure the angle on the new fuel rail bracket is the same as the old one. My new one was a little different and it caused the injectors to not seat properly (being slightly pushed to the side), causing a vacuum leak, causing the car to run like crap. It took me a few hours and a few times of taking the manifold off and putting it back on before I discovered the problem. A little bending and it was fine, the injectors seated and sealed and the car ran fine.

Replacing the PD is a very good idea if it hasn't been done before recently, and even on the S5's with it attached to the fuel rail it's not that much more expensive than doing it on an S4, maybe 25%. A few parts now are cheaper than having the car be completely destroyed later on.

Syncro

iTrader: (1)

The Banjo Bolt Pulsation Damper deletion mod should also be considered

Roen

iTrader: (2)

does that work on an S5?

Syncro

iTrader: (1)

You would need to switch to S4 fuel rails.

Icemark

Thanks for posting this Paul. I have for years been saying that the S5 PD design really is not better than the S4, and can just as easily leak.

I am glad you got it, before you had a Car'B'Que

pmr2000

Without a doubt any car that you value should carry a auto fire extinguisher, you never know when fuel or electrical problems will happen.

J-Rat

iTrader: (2)

All FC owners should carry a fire extinguisher!

Icemark

Lets modify that slightly:

All car and truck owners should carry a low residue fire extingisher with them at all times they are using the vehicle.

vaughnc

151K miles on my 1989 vert so far, PD must be living on borrowed time

Let's modify that even more, your extinguisher should have a READOUT GAUGE on it you can check from time to time, otherwise the el-chepo pop-up tester extinguishers will fail without you knowing it.

Icemark

Yep... I always recommend replacement every 100K-120K miles or 10 years regardless of series.

classicauto

iTrader: (3)

Damn right, that's its on the t-shirt baby!!!

You know you're a 7 owner when:

- You carry a fire extinguher because you ACTUALLY think your car might catch fire.

Carzy Driver

HAHAHAHAHA!!!

Even those go bad without you knowing it. I needed one when my S10 caught fire due to bad injector o-rings. saw the flames, grabbed the extinguisher, pulled the pin, and squeezed the handle. nothing happened and the gauge was reading FULL. lucky there was a water hose nearby.