Ryde _Or_Die

Isn't the pulsation damper just like a bolt with a washer thing around it really? Not exactly, but not much more to it right? How big is it anyways? Where exactly is it? I swear it does not seem like a $100 part. $10, maybe up to $30 but that would be alot. How in the hell is it $124?? I was going to change it just to be precautious. With a price tag like that I need to know that it needs replaced. I smell a gas type smell but I always have had that. Figured I was running rich & the holes in my exhaust weren't helpin the smell. Now that someone brought it up a few weeks ago it made me think. Could this be the reason for my high idle? Thanks alot.

MIKE-P-28

iTrader: (1)

Man I feel ya totally. I freaking bought one today for my 88 vert, cuz I dont want my garage, house, or possibly me or my son on fire.

But its just like anything for a Mazda its ALL highway ******* robbery!

Man just bought a rebuild kit for my 85 12A a month or so back and I paid over 800 for it! Man for 800 on a piston motor, you get new everything and hi preformance at that. A re ring kit for a chevy or ford V8 is like 80 bucks! The apex seals alone are 46 / ea for a rotary.. Dont get me wrong I love my rotary but dammit man, RIP OFF RIP OFF Man you can go to lowe's and buy enough steel to make 250 apex seals for 4 bucks!

Whenever in doubt on a Mazda, use the rip off rule of thumb. Whatever it should cost multiply it by 10 times. If its preformace double it again.

I guess its the price to pay here

tesla042

It wouldn't cause your high idle.

It's located under the upper intake manifold. Sorta behind the alternator.. Actually, right behind the OMP control rod. Look for a yellowish plastic cap. That's the end of it. See if you can pop it off with your hand/screwdriver. Inside, there is a metal thing (the actual PD itself). If the screw is out, it's a high risk one. You may start your car with the cap off, and see if you can see/smell/feel gas coming out of the hole at the end. **DO NOT PUT THE SCREW BACK IN**, as that will make it worse.

You can get an 89-91 primary fuel rail, which has the PD integral to it, and can not leak. I hear it's a direct swap, but may require new fuel hoses (which you should replace anyway... use FI hose, not carb hose). I also hear you can get some funny banjo bolt (that is REAL hard to find), and it will replace it. As for me, I cut the PD off the nut, and I'm going to try to weld it closed. I know it may be bad for the injectors, but this is only a temporary solution, as I plan to pull the motor later and port it anyway...

-Tesla

Ryde _Or_Die

Ya, I didn't think it would cause my high idle, just figured cuz it causes a weakness in the fuel flow it could allow more fuel to flow and raise my idle or something like that. Oh well.

DroptopRX7

iTrader: (12)

Just change it for the 89-91 and be done with it. Integral to the part, no plastic covers or screws to fall out. Don't mess with it.
Right before moving from CA to SC I smelled gas when I put the car on the trailer. Put it in storage and didn't touch it for 2 months until I got time to put a PD on, that's how dangerous this stuff is. Hot manifold, gas squirting out, you get the picture!!!
Change your FI hose as well, its expensive, but don't use regular fuel line.
Also, the manual shows the 89-91 PD in there backwards to the orientation of the 88. Just put the 89-91 in there like your 88. By the way, you'll need a regular bolt. Your 88 PD has a raised mounting surface on one of the bolts, bolt is longer, so you need two bolts, same size for the 89-91 since it didn't have the raised mounting surface. Other than that, hookup is the same and you can reuse your 86-88 secondary rail. The 89-91 secondary rail won't fit anyway unless you change manifolds.
Easy, and I'm not Joe Mechanic here either!!!! read my non-start thread, sheesh!!!
Ralf

Blake

It is a banjo bolt with an internal diaphragm that absorbs the pulsations in the fuel line from the fuel pump and the injector cycling. It is more complex and fragile than it appears. If you have not done so already, check out my animation: HERE.

Why is it so expensive? Probably because it's a very critical part that, when it fails, tends to burn your entire car to the ground. They do fail (after 10 or more years and about a hundred thousand miles!) but do you think an aftermarket company could do better than Mazda? And do you think anyone would accept the liability implications of selling something that is bound to fail eventually?

If you are not willing to spend a lousy $130 for 10 years of additional protection, I'm speechless. This is insurance plain and simple! If you are that cheap, then just go out and buy an M12 x 1.25 banjo bolt and eliminate it entirely. Can't say if that will be good for the fuel pump or injectors (and consequently the engine itself) but it would be cheaper than replacing it and safer than not replacing it. Your call, your car.

DroptopRX7

iTrader: (12)

Agree with Blake.
Good job on that animation. I've seen it before on the teamfc3s site, haven't I?
Ralf

Blake

This is not good advice. Yes, any PD missing the screw is suspect, but if the screw falls out, put it back in unless you are immediately taking the car off the road and replacing the PD! Also, put a dab of silicone around the head to keep it from backing out without disabling it (it still needs to move in and out freely). Without the screw, the diaphragm will overtravel and possibly slap against the end of the internal fuel passage leading to the injectors. This is almost certain to help it fail, though I once had one fail with the screw firmly in place. Eventually they will fail regardless. Later, 89+ PDs are designed to not need a screw. As you can see in the animation, the outgoing fuel passage is larger, has notches, and there is a large reservoir of fuel on that side. This allows the diaphragm to slap against the fuel passage without cutting off the fuel flow to the injectors momentarily.

So, to repeat: If the screw falls out, put it back! If it comes loose, tighten it! Even if you have no apparent problems, put a dab of silicone sealer anout the screw head. If you suspect a leak, or just want to play it safe, (1) replace the PD with the stock replacement Mazda part, (2) upgrade to an 89+ fuel rail with the improved built-in PD, or (3) eliminate the PD with a banjo bolt. 'Nuff said?

Blake

Ahem, I meant around the screw head. Also, I should clarify that when I say "tighten" the screw, it just means just get it snug; not torque the bastard down as hard as you can. What it screws into is a metal center section of the rubber diaphragm. If you overtighten it, the diaphragm will twist and possibly tear. Snug. A touch of locktite on the threads might be a good idea, too. Then, as I already said, follow that up with the silicone around the head and make plans to replace it eventually.

HOZZMANRX7

iTrader: (43)

Ryde _Or_Die

So if the screw of the PD is in then it is good? Or pretty much so if there is no fuel leaking when the engine is on?

Blake

The only good PD is a new PD. Over 100,000 miles, how many billions of cycles do you think it goes through? This is why I don't think people should spend so much time bitching about replacing them. It should be a standard maintenance item for the old modular screw-type.