will anything happen if i take that thing off? i have an aftermarket fpr and the stock fpr is gone

 

dont. It smoothens out the fuel flow. If your worried about the pd leaking you can put an 89-91 in there or use a remote PD off an MPV.

 

It doesn't matter.&nbsp I've known people who have done it with no ill effects.



-Ted

 

NO DON'T DO IT YOU'LL START PULSING!!!!!!! yeah I don't know how much pulsing it does but alot of cars don't have it. Just don't by a pulsing fuel pump?????

 

cymfc3s said no and reted said it's ok and amemiya confused me. let me rephrase the question "has anyone tried running their car without a pulsation dampener and did it/does it run ok?" thanks for the replies guys.

 

What would you put in place of it?

 

nothing. just run a line from the filter to the rail

 

I tried asking this same question a couple of weeks ago and couldn't get a straight answer either. I am in the parts gathering phase and am about to try it out. I am taking my PD off and replacing it with a 12mm x 1.25 banjo bolt with crush seals (ultimately ordered it from Earl's Performance direct, called them up and asked for a 12mm x 1.25 banjo bolt only without fittings).

My thinking is that if a car idles okay with a leaking PD which had a screw loose, then it probably will idle okay without a pd.

How much damping can a leaking pulsation damper damp with a broken diaphragm and loose screw?

Say that ten times fast.

Good luck on your quest for answers, I can't give you an answer today, but hopefully soon.

-john

 

I one engine I ripped apart earlier I don't even think had one.

 

I can't give you a definite yes or no, but consider this: most fuel injected cars I've seen made in the last 20 years have had one. If it wasn't required, manufacturers wouldn't put it in.
To make an educated guess, if you have tiny consistent pressure fluctuations in the fuel rails, each injector pulse will inject a different amount of fuel, some a bit lean, some a bit rich, some OK. This will reduce the efficiency of the motor. The FPR will have no effect on all of this.
Just replace it with a stock one, they don't cost much. Remember the first one lasted 15 years...

 

true, but look at all of the unneeded extras mazdxa tossed on the RX-7, ya never know.

 

i dont really know about this....but,wont the long term effects of not running a pd negative on the injectors?i mean,could be a total non-issue,but would it not bombard them with a bunch of pressure waves[maybe not 'couse its a looped system],you know,like the water hammer syndrome in plumming when you apruptly shut a faucet off.[which is why,idealy,you should t off a short capped section of pipe,facing up,so it creates a air pocket wich will absorb the force].i dunno.personnaly,i'm going with a mpv pd.why mess with it when its so easy to still have the sytem work the way it was intended.and,like nzconvertible mentioned,if nothing else,i could see it messing with the mixture a li'll bit.
david

 

On the contrary, from Mazda's point of view every single piece was required, whether to make the car easier it drive, use less gas, make it quiet, make it legal in different countries, make it easy to sell, make it last 15+ years, etc, etc. Just because YOU don't want it, doesn't mean it wasn't required for some reason.

 

I believe you and Node each have good points here. First of all, Mazda did see that all of those pieces were necessary. thing is, does your car have a PD (read Catalytic convertor)? If you removed the PD (again, catalytic convertor) and put a straight connection between, would the car run ok?
Back to the original question though, I think most of the pulsations would be taken care of by the head loss in the small fuel lines, but if you were building the car for someone else, would you or would you not want to cover your ***? I'd say the car should run alright without the pulsation damper, but I haven't altered mine.

 

I did remove my cat because I don't have to pass emissions (and it runs better), but Mazda did, so they put you on. I just think "all those unneeded extras" is a bit naive, that's all. No biggie

The pulsations are very small in amplitude, so are unlikly to be affected by the lines, but the injector pulse is so small (a few milliseconds) that the small pressure difference would have an effect, admittedly a small one.

 

Not to insult any other members of the forum, but just to clear something up. Whatever Ted(RETed) says GO'S. Dont argue with it, dont challenge it, it is scientific fact. Ted is the MAN.

 

The damper is designed to get rid of or minimize pulsations due to having only two fuel injectors per fuel rail.&nbsp In theory it's a good design - it's purely there to keep fuel flow consistent when the fuel injectors are firing.

In actuality, removing the PD does not affect fuel delivery - that's all that matters.&nbsp With a fuel pressure gauge, you'll see the fuel rail pulsations (if you've got the FP gauge sensor installed on one of the rails) increase, but this still doesn't affect fuel delivery.

This is based on my experience tuning an FC on the dyno with an A'PEXi S-AFC before&after PD removal - the fuel requirements were still the same before&after, which in my book means nothing harmful was done with the PD removal.

Now, what does this means?&nbsp It could be that the stock fuel rails are large enough to handle the added pulsations from the PD removal.&nbsp It could also be the stock rubber fuel hose is also helping dampen the pulsations.&nbsp Bottom line, PD removal doesn't affect fuel delivery - which is what we were after.



-Ted

 

thak you for clearing that up everyone. in conclusion i think that i'll take mine off. as long as it wont starv certain injectors it's a go for me.

 

Welp, taking into consideration that ANY PD will leak and catch on fire, I'd rather take the banjo bolt option anyday...

Good luck!




-Ted

 

Does anyome have a pic of a PD on an 87 T2?