phinsn98

iTrader: (2)

I've looked and have not found an answer to this. I'm trying to find out if there has been a design change to the factory S4 PD. I replaced mine two years ago for leaking fuel and it's going again. It's a little annoying to have to drop $125 on a part to make sure your car doesn't blow up. Mazda should have resolved this issue years ago. If anyone has any ideas other then a banjo fitting please chime in. Some say they use the 89-91 PD but it's part of the fuel rail. I'm not sure...does it fit an S4 with no problem? Does it require any mods? Just bought my fire extinguisher today. Let's just hope I don't need to use it before I buy the part.

Late

Project84

*cough*banjo bolt *cough*

My88Se

iTrader: (10)

I would advise against using the banjo bolt. There is a reason why it is on there, although some think that it is an insignificant part.

I believe that the s5 fuel rail is a direct bolt on.

Icemark

There was rumored (and yet still unconfirmed in my book) new design for the S4 PD. I suspect since the S5 rail/PD combo bolts right in, that the replacement part was simply a S5 rail/PD combo.

The S5 rail does have the same un-sealed draw back that the S4 PD has, so (as proven in other members posts) it is just as likely to fail.

But the real worry would be why after only two years your PD has failed again. Did you use a brand new part or a junk yard part? And is/are the stock fan(s) still working correctly? It would seem that if it has failed either the part was old/used or that the underhood temps are way too high in your vehicle.

The Banjo bolt replacement that project84 mentions should only be considered a temp fix and not for any car that sees high performance or race use.

Project84

Yeah, if you want a permanent replacement, ru parallel fuel rails and ditch the pulsation dampener.

DrifterS4

Hey phinsn98
Are you the same guy that i met up in margated. if it is whats up man. hows everything,

NZConvertible

The PD should last at least 10 years, more like 15. If yours really has failed again (what do you mean "going"?) then I think either you were unlucky enough to get a faulty one (take it back and show Mazda) or you have another problem somewhere that's caused this.

A parallel rail arrangement and the PD have nothing to do with each other. Ideally you should still run a PD with parallel rails.

Project84

Sure it does. You don't see a PD in the schematic do you? No PD= no PD leaking and causing a fire. Thats what they have to do with each other. Ideally I want a car that I won't have to worry about catching fire due to a manufacturing defect. Mazda won't fix the problem so I will.

DCRotor

iTrader: (2)

Amen brother!!

NZConvertible

There's no PD in the pic because the author didn't draw one. A parallel rail arrangement doesn't mean you can't run a PD, nor does it mean you should run without one.
You don't need a parallel rail arrangement to eliminate the PD, which is what you're incorrectly implying.

phinsn98

iTrader: (2)

To answer your question the PD was purchased new from Mazda along with new injector o rings. As far as heat is concerned. It's not an issue. The car doesn't go past the 25% mark on the temp guage unless I'm in stop and go traffic on a 100+ degree day with the AC on then it doesn't go past the 50% mark. It's not a temp thing. It just flat out failed. The question I have is how long do they sit in inventory. If that diaphram is say 12 years old sitting on the shelf then how long will it last. Everything has a shelf life. As far as bad luck I guess so. As far as how I know. The car has been running really rich or at least that's what it smelled like. I replace the throttle cable and it smells like gas down behind the intake. I'm gonna take the intercooler off tomorrow to see what it looks like.

phinsn98

iTrader: (2)

Hey drifter S4 yep you found me. Keep reading this stuff you'll learn alot about your car. Don't forget some of the other sites like teamfc3s.org and nopistons.com there's alot of info out there. feel free to drop me a line as well.

late,
dave

NZConvertible

Coolant temp has nothing at all to do with underbonnet temp. The temp gauge won't give you any indication of how hot it is under there.

I say take it back to Mazda and see what they say. Hopefully you've still got the receipt, but if you go in there yelling and screaming about potential underbonnet fires you might get lucky. It's worth a try.

Project84

No, all I need is a banjo bolt, which I state earlier so I'm not incorrectly implying anything. Either method that I stated will allow the engine to run and decrease the risk of the car catching fire. Your way of doing things isn't the only way of doing things.

Icemark

Banjo Bolt = Band aid only. Not a fix.

Project84

Says who? What says you can't leave it on indefinately?

Icemark

Says anyone that knows anything about performance fuel injected vehicles and fluid dynamics.

Project84

So whats going to happen with a banjo bolt? It ain't going to leak and catch my car on fire.

Icemark

Ah man, do we have to go through this again?

No, a bolt probably is not gonna leak, but there will be other issues (as covered countless times) including lean running at only specific RPMS and possible on different rotors, as well as injector and hose failure.

So, is never leaking worth blowing out injectors, or fuel lines (wanna see the fire from that???) or a apex seal?

Project84

Why don't jet engines use PDs? They have nozzle that atomize fuel, similar to a fuel injector.

Icemark

I don't know the fluid dynamics of a jet engine.

But I would guess that a variable nozzle is different than a valve that switches on 100% and then back off.

A fuel injector is that valve that is either open 100% or closed

Project84

I have more questions about the necessity of a PD because I think it is somewhat over rated, but I will ask them elsewhere. There are a bunch of people on this thread who use them and I don't see as many threads about fuel lines rupturing and "blown out injectors" as I do about PDs leaking.

NZConvertible

You said "if you want a permanent replacement, run parallel fuel rails and ditch the pulsation dampener." I simply stated that it is not necessary to switch to parallel rails (massive overkill in most cars) to ditch the PD, nor is it necessary to run parallel rails without a PD. You suggestion of switching parallel rails wasn't relevant to the decision of whether or not to keep the PD.
A jet engine injector is not even vaguely similar in operation to an injector on a petrol engine. They flow continuously, so there are no pulsations to damp.
Ask yourself this question. Why does every manufacturer use a pulsation damper on every fuel-injected engine they've made almost since production EFI started? That doesn't overrated to me.

Project84

yeah, I said run parallel fuel rails. Cause my response before that was to replace the PD with a banjo bolt, but na, that wasn't good enough. Won't catch the car on fire, way cheaper, and many people have done it already, but not good enough. Ok, so why not re-route the whole fuel system? Maybe not a good idea for the guy who posted this thread cause he probably doesn't have 1680cc secondaries like me. Overkill. It would work, but overkill in this situation. So then I hear fluid dynamics and I begin to wonder, whats this pulsation dampener really for? I'm an aircraft mechanic. Been working on different aircraft for 6 years. They got fluids in them. Their fuel systems are under way more pressure than that of a car. Why don't jet engines have them I ask myself. Yeah, jet engine fuel nozzles don't pulse like in a car, but that has nothing to do with the PD. I looked into it and found out that the PD is to reduce the pulsations created by the pump. Not every system design needs a PD because the pusations may not be large enough to create a problem, though they may be used by the system designer anyway. Maybe thats why aircraft fuel systems don't have them. I don't see one on my Ford Explorer either but what ever, I got this.

One.

Rex4Life

Here's why you need a PD.

Did you ever open a faucet and then shut it real quick? Hear a clank sound in the pipe, that noise is called water hammer and is basically a shock wave travelling from the valve back into the rest of the piping system.

Now imagine opening and closing that valve (injector) many times per second--this sends mini shock waves back through the fuel piping sytem. Well depending upon the piping geometry and the frequency of operation, the shock waves can create pockets of fuel that have very high pressure and very low pressure. It just depends upon how the waves are intersecting. Kind of how sound in a room can have dead spots.

If one of your injectors happens to be in that low pressure zone created by the intersecting waves, then there is the possibility of running lean on that rotor.

I just bought a new PD for my rebuild but was thinking about using this one.



I posted it a while back and no one said they have used it, here is the link

Hope this answers your questions.

Scott