paintx

Picture 1 shows the car off


Picture 2 shows the car on

I知 not sure why the gauge is reading this. I recently had a j-spec turbo swap done and I知 not sure is the gauge is broken or not hook up properly?

paintx

heres picture 2

Rattaan

From that first pic, I'd say it's broken. Did it jump up really high before dropping there to nothingville? My '90 did and then dropped completely. Turns out the sender went bad, caused a surge of power to the electrical guage in the dash, which caused the guage to melt a peice of metal through a peice of plastic holding the needle, and die. I had to replace both parts. I would start looking for replacements if you want to know your oil pressure.

Rattaan

WHOA, turn the car off now! Disconnect that sender, it's bad! Your gauge in the dash is ok, but it won't be for long with the sender giving it that signal.

Rattaan

^^^ just looked at the second pic and tried to warn you in time to save your dash guage, hope you got it in time

theflatlander

iTrader: (3)

my gauge is like the first pic when off but doesn't shoot straight up like the second pic.

Icemark

The oil pressure sender condensor is not hooked up

Icemark

Ah... yeah... right...

The condensor is not hooked up correctly

pengarufoo

i'm guessing the wire going to the sender is disconnected and/or shorting somewhere. the needle appears to have shifted on it's axle so it rests below the normal 0 point. My suggestion is to simply get a new sender and gauge since the stock sender and gauge even when working properly are crap.

Rattaan

Oil pressure sender condensor? or oil pressure control valve? Could you explain why it would be that and not the sender? All I'm saying is that my sender went bad, it made the needle go to it's furthest point on the gauge by sending too much current, which caused part of the gauge to become too hot (it used a bimetal strip to move the needle) and melt through a plastic piece that held the needle. Then it dropped to 0 pressure and never moved again. I took the gauge apart and found that this was what happened. I replaced the sender and the gauge itself and fixed the problem.

Icemark

Oil pressure sender condensor is required for the oil pressure sender and gauge to work correctly.

Without the condensor hooked up properly the gauge will not read right and eventually fail (especialliy if the sender resistance is too low from the sender starting to fail).

The condensor is typically mounted to the top back of the engine or the clutch slave (depending on who's worked on the engine and if it has a manual or auto). The oil pressure wire, "T"s off to both the sender and the condensor.

Its pretty common for someone (shall we say, less experienced) doing an engine swap or clutch/tranny work, to forget to hook the condensor up or forget to mount it causing the problem exactly as described, by both of you.


Rattaan you said:
and
Your oil pressure sender can not send voltage to the dash. It only grounds. There is no voltage in the sensor (other than what is sent by the gauge itself). So there is no way the sender can send a "voltage surge". However the gauge itself does send voltage, and works on how much resistance there is too ground in the sender.

If the condensor is not there and the sender is bad the gauge can be damaged.

poor_red_neck

Would all of these plugs and such that a normal person would forget about, be covered in the Haynes manual or something? I mean, when and if I have to do a motor swap, I sure as hell couldn't remember EVERY plug/sensor to have to plug back in. (Not trying to hijack.... but since you're on the topic of sensors and such)

Icemark

In the schematics, and plug locators, yes they would.

TonyTurboII

Where is the sensor mounted? I just did my -RE swap and I need to find a way to hook it back up (the gauge).

Icemark

The sender is mounted just under where the oil filter mounts. The condensor mounts to the back to of the motor or too the clutch slave

Lodivigo

My gauge is doing the exact same thing, I'm trying to hunt down another condenser, you wouldn't happen to have a part # or something would you Icemark?

TonyTurboII

Thats what I thought. I dont think its in the same place on my -RE , cause theres an oil cooler line there.

pengarufoo

If the wire pops off the sender and shorts to the ground (chassis) it will make the needle peg and can cause too much current to go through the circuit (hence overheating the bimetallic strip which drives the gauge). The condensor is just a capacitor, it's absence should not cause the gauge to be damaged AFAIK.

Also, an internal short in the sender will have the same effect.

FYI, the sender itself has a bimetallic strip within just like the gauge does. This subject is not worth going deeper into, the stock sender and gauge are garbage, replace them with a much simpler aftermarket electronic sender+gauge kit.

Icemark

Rattaan

Thanks for the explanation. I didn't know if the sender itself sent current or voltage to the gauge directly, which is why I just said it caused it. Now that I see the picture there I know what it is, and remember asking about it before but I don't think anyone said what it was. That could have been worded better


This was the thread I asked about it before in https://www.rx7club.com/showthread.p...hreadid=221612

HAILERS

Pull the connector off the sender unit. Did the gauge needle not peg out now???? If the answer is *yes it does not peg out now*, then the sender is corrupt/bad/knackers. If the answer is *no, it still pegs out*, then the wiring b/t the gauge and the senders connector is grounded somewhere. Check and make sure you did not inadvertently ground the wire/connector for the condenser. Not the case???? Then with the key off disconnect both the gauge and the sender and ohm out the wire. It should show an open. IF it does not....find out where the short is.