skillzilla

iTrader: (1)

Hey peeps, I searched for awhile and came up with some good reads but nothing specific to this. In a nutshell, the stock oil pressure gauge is freakin SLOW! Bear with me, this is my first RX7 so I really have nothing to compare it to besides aftermarket gauges, but the thing seems like a sloth is controlling it in a tub of syrup or something.

OK bad analogy. Here is the scoop:

I got to the "crank it over and pray" point this weekend after a long time of working on the car, and went to prime the oil pump for the first time. I have the gauge sending unit wired in correctly (with teflon tape, good or bad? I put 2 wraps on it). Cranked the engine over with the CAS unplugged to build pressure, and saw nada on the gauge. Nothing. So I pull the oil filter and it has more oil than I put in there initially. Pull the sending unit and crank it over, oil squirts out the block. Im thinking cool, bad sending unit.

By this time Im getting impatient so I plug in the CAS and turn it over with starter fluid for a few seconds. Low and behold, the oil pressure gauge starts registering a bit. Im stoked as hell, so I get it ready and turn it over for real. Oil pressure looked good, right at about 60psi at idle but the gauge was seriously moving slower than ****. I would rev it a bit, wait a second or two, and the gauge would react.


So, long story (kinda) short, how quick to react is the gauge supposed to be? Could the teflon tape I wrapped on the threads of the sending unit cause it to be so slow? Also, I am pretty sure i located and grounded the condenser, but Im not 100% sure. Is it on the Front harness or the Engine harness? I have a small one-wire ring connector with a black box connected to ground, but its on the Front harness near the X-07 plug kinda, maybe a little higher towards the trailing coil plug (S5 TII harness). is that the condenser?

TIA for the long read, really. And the advice (I hope!)

jjwalker

My guage operates properly, but it is slow as hell to react. If anyone knows how to speed it up, let me know.

I would think that replacing the stock condensor (just a capacitor) with a much smaller uF type would solve the issue but I am unsure. Can anyone verify this?

Same goes with the fuel gauge. I don't care if it moves during decel and acceleration.

skillzilla

iTrader: (1)

How slow is yours, like seconds behind? My needle isnt even sweeping quickly, like I could rev it up and let it fall and the needle would barely move. if I rev it and hold it will slowly move to where it should be.

RotaryEvolution

iTrader: (30)

the way you described it is exactly how the oil pressure gauge is supposed to react. when i prime the oil system after a rebuild it barely will creep above the zero line, that is also normal.

skillzilla

iTrader: (1)

Sweet, thanks for the reply! Good to know everything is in order.

g14novak

iTrader: (1)

Like already stated, the stock oil pressure gauge is slow as dirt. If you want a more accurate gauge, your going to have to buy a oil filter pedestal and an after market bung and gauge.

jjwalker

So can anyone confirm my condensor theory? A capacitor SOMEWHERE is what makes that gauge react slowly. Basically, capacitor starts to charge apon the pressure rising, which slows down the rising of the guage. When the pressure lowers, power flows from the capacitor and slowly lowers the guage needle.

My theory is that the condensor (capacitor) on the grounding side is what causes this.

g14novak

iTrader: (1)

My theory is that all the stock gauges suck and should be replaced anyways. Playing with the electrical system is just asking for a fire.

Marshessn

iTrader: (-1)

Thats like saying "playing with an exhaust is just asking for a exhaust leak"
or
"playing with an engine is just asking for an engine failure"

you just have to know what you are doing.

jjwalker

Nice one champ. Sorry if I don't want a bunch of guages bolted to my dash and a pillar. Maybe I should just take my car to mazda every time something is wrong with it. I guess it works both ways though. I would never cut my springs, I'd get the parts and do it right.


But back to the topic at hand...

I'll take a look at the wiring diagrams and see what I can come up with.

g14novak

iTrader: (1)

I wouldn't have posted if I didn't have a prior experience with this. But go ahead, change out the condenser, all thats going to do is fry the sending unit.

All the gauges I plan on installing are going to replace the stock gauges on the cluster. I personally think if something doesn't work correctly to replace it, but thats just me. The cut springs are a temporary fix until I can get coil-overs.

jjwalker

So did you take the condensor off? Did you change the capacitance value of it? Did you just ground it straight to the body? If you have experience with this, then give us details on what you did.

g14novak

iTrader: (1)

I took the condenser off, the gauge stopped working (this is the point where I think I fried my original sending unit) so I put in a capacitor, still nothing. Changed the sending unit with another one I got from a local friend. The gauge started working a lot quicker than with the original sending unit I had so I just stuck with it. Maybe I fu*ked something up along the way, I don't know. I don't care to mess with it anymore because it works fine and quicker than the original gauge I was trying to speed up.

skillzilla

iTrader: (1)

This made me LOL.



At any rate, bump for more condenser theories or experiences. I have a Defi oil pressure gauge in my parts bin but its not going in until I swap interiors, help me speed up the stocker and Ill be your friend.

g14novak

iTrader: (1)

People think I'm joking. about 60% of FC's die from either kids drifting them straight into a wall or a PD/electrical fire. Hey HAILERS, you around? You want to let these nice people know how well the japs wired these cars?

All I did was swap out my sending unit and my gauge started working quicker. That's all the insight I can give you.

skillzilla

iTrader: (1)

It made me laugh because I rewired basically the entire front half of my car recently, aside from the headlight circuit. No issues at all.

Its also going to be a track car so lets see if I can stay out of that 60%. Me, I think both issues (drifting into a wall, bad wiring) sound like personal problems, but w/e

g14novak

iTrader: (1)

Well if you ask any if the wiring gurus on this forum, they'll all tell you a 10yr old with downs could have designed a better wiring system for the FC.

skillzilla

iTrader: (1)

True enough, and in that same thread it doesnt take a genius to work on it.

jjwalker

My condensor is attached to my driver side shock tower. I'll get a peak at what uF rating it has and see what i can come up with.