oil pressure issue
 

Yesterday afternoon I went to wash my car after pulling my cams to clean my hla's, they were getting pretty loud. Anyway I went to fire the car up and move the car like 20 feet, the hla's were even louder but i though it was just oil that needed to get to them. Any way I move the car, then i look down at the oil pressure gauge and it reads zero. I kill the car immediately, I check the sender and the sender wire, it seems alright. I must add that before this issue I had zero oil pressure issues. I wiggle the wire around then turn to the key to accessory to see if the gauge has changed, it hasn't. Now I start getting worried, I pull the filter to check for metal shaving, nothing I could see, that was terrible. The oil has 800 miles on it and so does the rebuilt engine, so me screwing something up or a bad bearing wouldn't be totally out of the realm of possibilities. Anyway I empty the filter and see nothing so I re-install it. Then I turn the key and find the car now has oil pressure. I start the car and run it for 20 seconds, the hla's are still really clanking so I shut it off, total run time maybe 30 seconds. I kill the car again and pull my oil feed line, which is dry. I pull the relay and pump the engine for a few seconds and nothing comes out. Now i get worried, so i pull the car into the garage and shut it off.

I know the oiling systems in these cars aren't terribly complicated, I'm planning on an oil change and a napa gold oil filter, I've been using valvoline 10w-30 for the last 800 miles, did a change after the first 10 miles of driving, all was good and clean, also replaced the filter aswell. It was replaced with the standard napa white filter, don't think its as bad as a fram, I think spec miata people swore by these. Could my sump be blocked? I think its unlikely, when i drain the oil i should be getting a good idea of the particles inside the oil. Is my pump bad? I'm not sure, I can't hear the sound of spinning broken gears, and I haven't beat on the car in a hundred miles.

So I know
-I gained oil pressure when I cleared and emptied the filter.
-still have no oil though the oil feed line
-still have a loud HLA tick

Anyone have any idea's on what the issues are?
Is there something obvious I am forgetting?

I would work on testing where all oil gets. The first is to open the plug hole on the passenger of the oil pump. It is right besides the alternator. Unplug the injectors, and coils, and remove the spark plugs. Turn the engine with key and have someone verify oil is coming out of there. After that I would check the oil pressure sender port using the same method. Then finally do it with the oil feed line. I am assuming that you are using the oil feed port on the driver side of the block.

Thanks lars, will check that next. Whats the likely hood of an oil pump failure? I'm assuming it hasn't failed if the sender is seeing pressure

Oil pumps usually don't just die unless you are going higher then 7200rpms or something goes through them. Occasionally the oil pump relief valve can stick and cause pressure issues. But if you are getting oil out the driver side turbo feed, then you have oil pressure, and I would start looking at the sender connector and such.

I just delt with this on my new engine. The wire going to the connector broke for my sender and it took me while to get that fixed.

So I opened up the oil filter, no chunks of metal, just dirt, not even a lot. I figured that my oil was probably ok so I haven't drained the oil yet. I the. Pulled the plug and turned over the engine for 15 seconds total. Still showed pressure on the gauge but nothing came out. I'm guessing I have a stuck relief valve. So does this mean I should just pull off my spare pump and swap it? Can I pull the front dressing and then pull the pump? Or will the whole engine have to be pulled?

Pulling the engine is required to swap the pump. If the gauge is showing pressure but that hole on the side is not I am a bit confused. Try pulling the oil pressure sender and cranking some to see. Or pull off oil filter and see if it shoots out.

Even though it's not a new pump, just try priming the pump beforehand. Open that spot near the allen bolt and fill with some oil.

the oil pan has to come off to take the oil pump off.

Yeah I forgot about the sump, saw all the bolts on the front and the idea piped into my head

Pulled filter nothing, bone dry I might add, tried priming the pump, still nothing. Then I pulled the wire to the pressure sender. The gauge still reads good pressure. It's a dummy gauge, the car is a 95, running on ms1 if it makes a difference

I did not realize that it was a dummy gauge. In that case I would go up to AutoZone or Advance and rent a manual OP sensor and plug that in and crank just to see. Otherwise plan on pulling the motor and swapping oil pump at the minimum. You can get new OEM ones for about $100.

I have a spare from my original 1.8, could I swap it over?

Yes it will swap over. I am not a fan of reusing oil pumps now.

What could/ would go wrong?

The oil pump relief valve sticks again is a possibility.

Stuck oil relief valve. Likely a piece of debris got sucked in the pump and it jammed up the valve open, so it won't build oil pressure now.

Best place to buy said refurbished oil pump? All I see is the fm high capacity pump and the super Miata pump. Is it an autozone item?

also I guess this is a good time to be swapping my crank because mine has a pretty bad keyway issue. Should I get acl bearings or should I just reuse the old 800 mile ones? I used oem ones before

Priority Mazda has them for around $100. If changing the crank I would plan all new bearings all around. I wouldn't bother with ACL on a street build.

I would personally use a new mazda pump, bought from a mazda dealer if I wanted a new high quality pump that I would trust to work. I've always used the old mazda pumps on my motors without issue, but if I ever put a new on in it would be a new mazda pump. But I also use mazda seals, mazda gaskets, etc. I would not use a refurbished pump, new.

I have run used oem bearings (that check out to be in tolerance and show almost no wear at all) and ACL bearings, both without issue. Both worked well.

http://prioritymazdaparts.com/oil-pump-bp4w-14-100a/
would this one work or should it be year specific, didn't they switch to a high flow pump with vvt?

99-00 and 01+ have different oil pumps, VVT pump is a higher volume pump vs 99-00.