That stuff on the old pump is a concern . Was it on the sock as well or just as per that pic. ? Kinda looks like someone used excessive lube when they pushed the pump into the cradle .

 

I just took it all back apart again and looked through it religiously. Everything is clean except the internal filter that cannot be removed. I'll take it out after work tomorrow and check the pressuresagain.

 

It was on the bottom of the pump and on top of the sock. It does look like someone lubed the **** out of it but I have no idea why as it doesn't need anything there

 

You mentioned premix I think . What are you using in what concentration and how old is it ?

 

I was using Lucas Oil Sythetic when I first bought it. Put on about 10k miles (Bought with 50k). Then changed the S1 pump to an S2 for no specific reason. Drove 500 miles. Parked for winter with stable in gas. Stable was put in a full tank of non premixed gas. When I pulled it out at beginning of this summer, I drained the gas, and started using idemitsu.

I've always put in 8oz per tank, I run them to 1/16 before I fill back up.

 

My guess is that gunk formed over time because of either the stabilizer or the premix or a reaction between the two. Hard to imagine that it's just an over enthusiastic lube job.
I've had something similar happen when I used two stroke oil that was a few years old . It completely clogged up the sock filter .

 

Wow - 8 oz/tank is a 1:275 ratio. Are certain premixes suspect for clogging the pump socks?

 

I'm no chemist but I would imagine that most people that are on this forum, premix. I would also assume that a lot the knowledgeable members on here store them for the winter. What I'm trying to say is if the stabil in the tank (of pure gas, then drained) was a terrible idea, we would have known a LONG time ago. I'm sure you know more about cars than I do, but I have a hard time believing that

 

Many moons ago , there were a lot of people experimenting with all sorts of concoctions. Some of these ended up causing the sort of gunk shown on the previous page. Can't recall exactly what caused the issue but it was a mix of a few things that by themselves would almost certainly have been ok. That plus my own experience from using old 2 stroke leads me to believe something like that has happened here .

 

Yeah, if you intend to store the car just for the winter it's better to drive it near empty and then pump the rest out or just refill with straight quality premium gasoline/fuel. I never was a big fan of premix. If you refill full to the brim with straight fuel and let sit for the winter it should be fine without any additive. Oxidation from air (partially filled tank) is more of an issue.

The issue with any chemical concoction is you likely don't know what the net effect might be long term. People assert that stuff without ever really knowing. Most of the people who Promoted the magic elixer way back when called me Debbie Downer etc., but they came and went without ever proving their case. Likely because the opposite occurred.



.

 

I use the exact same brands as you for stabilizer and premix (Idemitsu) and have not had any problems. I have to admit that I typically burn the tank of fuel down to about 1/8th tank after storage before I refill with use of premix and then I only premix every third or fourth tank.

 

What's winter?

 

A magical time when everything fun dies

 

Oh you mean boost season

 

Fixed.

 

Not sure what that goop is all on there, but it's obviously the source behind the problem

 

The fine filter is the white housing that the pump sits inside of. It's replaceable. You'll need to order a new one and see if that solves the problem. It likely wasn't the pump if that's the case.

 

I know the inner filter is wet and all, and yours was brand new, but does mine appear to be way darker than what should be normal by chance?

Also, I just looked in my pressure gauge and adapter, clean as a whistle. I would think if that sludge made its way into the fuel line I'd see something the nooks and crannies of the fittings/etc.

Also, that sludge wasn't on the bottom of the sock, which I would think would mainly collect it especially directly below the suction port on the pump. It seems to me that crap was on the pump when I bought it. The tank itself is also clean

 

I thought that wasn't replaceable? I know it can be removed and whatnot but I didn't know mazda sold just that

 

Yep.

 

The Mazda part no. is N3R1-13-ZE0, about $83 msrp

 

Not sure if we're miscommunicating though. Is the problem occurring, but with good or bad fuel line pressure?

 

The way it is sitting , plus the fact that it was only on the top of the sock .... I wonder if someone jizzed on it before it was assembled . Then the gunk found its way into the rest of fuel system .

 

Every time it has happened, fuel pressure plummeted. It has never happened with 50+ psi before that I know of. When it happened again, after putting in your pump, I wasn't able to read my pressure gauge so I'm not sure what happened that time. I'm going to figure out if the pressure still drops with your pump very soon

Ill look into getting a new fine filter

But I have not found that sludge anywhere except for where it was on the pictures. Between the pump and sock.

 

As of right now, it seems to be working fine. Since the last post I took the pump assembly out again and sprayed a bunch of carb cleaner into the fine filter assembly and tried what I could to clean it out.

I took it to work today, about 50 miles, and did around 20 wot pulls and didn't get one sputter nor did it lean out.

I do have another S2 assembly coming soon in case it happens again. If it does, then I'll just overhaul the whole fuel system as that's where the issue is stemming from.

If anything important comes up I'll post on here again. THANKS EVERYONE FOR THE HELP AND STICKING WITH IT THROUGH THE COMPLICATED SYMPTOM DESCRIPTION.