well it's been a decade but I'm back, the SA22s are long gone and I'm now the shell shocked owner of a suspiciously cheap 1997 FD3S

anyway onto the questions. Regarding the turbo control system, Wikipedia says that for the series 7 the system was "simplified". When people on here post up the "simplified vacuum system" diagram, is this actually the stock series 7 diagram? Or is it a modification done to the earlier series cars to make it more simple? In other words, should I pay the "simplified" diagram any attention?

Second question, at the front left of the engine (as you look into the bay) at the very bottom of the front case there's some broken wires or cut wires left sticking out the side. Looks like 4 wires, two black, a red and a yellow. I can't see where they should be connected to. Is there a sensor or actuator or something down there? Should I be worried?
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​​​​Oh and bonus question, what body kit is this?

 

Congratulations on the suspiciously cheap FD!

I am sure a few FD owners are super familiar with the wiring unless it was replaced, upgraded or added too.

When you have the time, some pics would be great.

 

Right in the centre of the photo there, bit of a mess sorry

also wondering what style intake this is? (Aside from "ugly and in need of new filters")

 

Welcome back*(edit) to the forum!

I believe the only bit of harness that travels down there is the harness to the OMP (Oil Metering Pump). Do you know if it's been deleted? It sits on the left side (when looking at the engine bay) right above the oil pan, way easier to see it under the car.



There's also a bit of wiring in that general area for your CAS sensors. But I doubt it's that.

 

Not sure on the kit but the rats nest simplification being referenced is the change to the "black box" over the standard demon child that is the traditional "rats nest". The wires you have down there are likely from some old electronics that are no longer installed. Highly doubt it's omp related although that is the only thing in that area that has wires going to it. As mentioned, take a peek from underneath.

 

previous owner says it was still running the OMP so I hope it's not that! the wiring colours kinda look the same so that's a bit of a concern. you'd have to be a bit of a caveman to savage the wiring as opposed to just unplugging it... thanks for the replies, I'll take a look tomorrow

I would start a regular thread as I will definitely have a lot of questions about this car, but they're all newbie questions so I guess I'll stay here

It does seem to start perfectly fine hot and cold, drives great and sounds amazing, I haven't found the "OH.... so THAT'S why it was cheap" moment yet

 

hmm well unfortunately it's definitely the wiring going into the metering pump

"OH, so THAT'S why it was cheap"

the pump looks quite a bit different to what I see on the internet though, there's no grey plug at the bottom, the wires seem to go straight into the unit? but the wiring into the unit is completely bare of insulation!! so either the thing shorted out somehow and burned the insulation off, or maybe the plug has somehow cracked and fallen away with age? too hard to get a picture

Anyway I am hoping against hope that the pump is dumb enough to run even if it's disconnected. I have asked the previous owner if he knows anything about it (although I'm trying to not bother him too much) will see what he says. has an aftermarket ECU so wouldn't have gone into limp mode

 

OK mystery solved, I found the rest of the OMP harness wrapped around the crank pulley looks like it's floated into it and gotten torn to pieces. It's disconnected the main OMP plug up behind the alternator at the same time and pulled some vacuum hoses apart up there, the previous owner said he replaced a solenoid as it wasn't boosting properly, then the problem came back shortly after. I'm hoping that the "problem coming back" was the vac line coming off, and that would suggest this is all a recent development....

anyway thanks for reading my blog

 

Best case scenario then. Delete it the rest of the way and premix. Cover the bare wires and press on. You don't need it anyway

 

the engine has an aftermarket ECU so the pump not being plugged in isn't causing any fault codes or anything, do I actually need to remove anything else or will it just sit there happily with no wiring going to it?

 

I can't answer directly about if you can leave a non-working pump installed. since you have a non- working OMP, what I will tell you is, do not run the engine without premix in the fuel. This is very important!!

You can remove the OMP, buy a block off plate and use premix oil in your fuel from here on out. If you do not want to use additive, repair the wire harness and look for oil in the OMP hoses. If you do not prime the OPM, premix is needed until the hoses are full. Also very important.

 

yip first thing I did was premix the fuel that was still in it

I'm trying not to think about how long it might've been driven without the OMP working. When I asked the previous owner he said he thinks that without any input the pump may have continued to add "idle" levels of oil to the chamber. I would certainly like to think that Mazda would have this as a fail-safe (really it should fail to "max flow" mode in my opinion). No doubt it has shortened the engine life, just hopefully not by too much

Edit: OK I've just read a bit of the manual and I see it's a stepper-motor controlled unit, so it won't be spring biased in either direction, which is probably a good thing, it will have stayed in whatever position the pump was in when the wires got ripped out. there's a failsafe which results in the ECU driving the pump to minimum flow mode as the previous owner suggested, except the pump won't have gone anywhere with no wires attached to it! So yeah I guess it needs to come out because I have no idea how much oil it's feeding into the engine currently. I might put my future questions in general 3rd gen as I suspect there's a bit more traffic in that section

 

Yes, you can leave it in place. It just becomes a vestigial component.