Rotary4tw

iTrader: (3)

I'm having issues with my Defi D A/F gauge. I searched on the issue and found one thread about a bad A/F install, but it never seemed to reach any resolution. I appreciate any comments in advance.

I have it hooked up correctly, but I seem to not be getting an accurate reading.

There are 5 wires coming from the back of it, 4 in one section, and 1 in the other:

1) Constant 12v
2) Accessory
3) Illumination
4) Ground

and

1) o2 Sensor

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What is happening is when the car is running, the needle will rest in the off position at 6:00, and then snap up to stoich for a moment, and then drop back down to 6:00, and continue to bounce back and forth. There is no relationship to how much gas I am giving or any other function of the car. I am unable to get it to read anything besides stoich or off. (The auto-check and scrolling feature works when the car is turned off and on)



I think it may just be the ground, which is currently shared with the Boost Gauge, Water Temp, and Oil Temp gauges.

If the issue is the ground, do I need a separate ground for each one of them? I also noticed that my two temp gauges seem to be about 20-30 degrees off of where they should be as well. (Oil at about 140-160 degrees after properly warmed and water between 160-170 when the radiator fans activated and the thermostat was opened.)

Thank you in advance for any comments you may share, I'm going to attempt a write-up of my gauge install which took about 6 hours yesterday. Here is a sample pic!



-Rotary4tw

crosswound

Yea please I am having trouble with my water and oil gauges. I didn't want to go purchase anymore gauges until I got those working.

Rotary4tw

iTrader: (3)

I just tested my Defi-D temp gauges in a pot of boiling water, and they work very very well.

Make sure that they are located in a good point in the system for your water and oil. I am using a Greddy adaptor for the Oil temp gauge, and it sits right under the oil filter like so. I believe the only way it would be getting a bad reading would be if the system is too low on oil. I spilled a small amount yesterday during the install, but it should be full.



For the water temp, I attempted to go into the 3/8ths hole on the top of the housing, but feel like I was just getting air. I always seem to have a little bit of air in my system due to a cooling system pressure issue, so that rules out the top manifold hose as well.

I'm going to next attempt to install the water temp gauge in the place of the "low coolant" sensor 3/8ths hole at the base of the housing. It's low enough that it will give me a reading. (My coolant won't stay topped off, but will never drop below that point) The previous owners already detached the warning buzzer somewhere, so for the short term I'm going to try a mount there.

Good luck to you!

-Rotary4tw

Sgtblue

iTrader: (16)

Don't know about the others, but the easiest place for the water temp is in the TB coolant hose. Really a piece of cake to install. I followed DaleClark's a how-to using a DEFI 'D' series as well. Accurate readings without having to wait for the thermostat to open, and NO drilling, tapping etc. I got the fittings listed in post #36... < $5.
Here's a link:
https://www.rx7club.com/showthread.p...highlight=temp

13bmaniac

iTrader: (5)

tell me what is the series model i have a problem like that just like 2 months ago it is a series that came with inverted wires,at least mines.
tell me the model and series and i let you know

|aFk| LiMiTz

what sizes are your guages, I am planning on picking up a set from FlyRX7 and wanted to see how they look in either 52mm or 60mm. I don't want guages that are too big on the dash. More pics!!!!

Rotary4tw

iTrader: (3)

My gauges are all 52mm Defi-D series. I really like them.



But there is pain behind this story...

Firstly, the boost gauge works like a charm. It's much more responsive then my previous gauge (Autometer Phantom) and shows that my vacuum is a little stronger. This makes me happy.

Air/Fuel gauge is still wacky and out of control. I am attempting to give it a separate ground wire, but got sidetracked trying to fix my temp gauges.

My Oil temp gauge seems to appear like it's working, but I have no way to determine what an accurate reading is because I'm not used to oil temps. Should oil temps be:

1) 15-30 degrees f. above the water temp?
2) 15-30 degrees f. below the water temp?
3) About the same as the water temp?

Currently, the oil temps have not gone over 200, and that was post thermo with me warming the car at an idle to bring up the temps for the water gauge. My car is a touring with one oil cooler.

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Now, the problem. The water temp. I know it's off, the fans kick on, the thermo opens, and my gauge is still dicking around the 160-180 range on the dial. Its first mounting location was on top of the housing, in the spot that is freeable with the proper hex head. It pointed straight down and dipped into the coolant.

"It must not be dipping far enough to get a good reading, and it's likely just air up at the very top there."

Additionally, I have some sort of o-ring/hose leak that causes me to very be able to keep my coolant full at the very top. (It will still be visible in the housing if you take the top off, but never at the very top. It will stay visible for days, but run it for 1 heat up cool down session and it retreats from the brim)

That is why I can't just "top it off" to get a good reading.

I tested the sender in a pot of boiling water, and it shot to 195f (it cooled a little by the time I got it to the garage). I was very happy, because this means the gauge is working properly. Now I just need to find a better place to mount it.

Why not use the manifold hose in the back near the firewall? After all, I'm very familiar with it after my nipple cracked coming off the engine and I had to pull the UIM and friends to fix it. But here is the thing, I always seem to have air up in that hose, or something, which causes it to get shitty readings as well. (I tested this spot with a mechanical autometer gauge last week, and it wouldn't even activate.) Often times when I touch the hose after a drive, it's not warm... no coolant. That spot is out too. Likely air that gets trapped up there just like the top of my housing.

Where else could I possibly mount the temp sender that would give me a constant read of the temps, and I wouldn't have to worry about getting air trapped there?

I thought I was so damned clever...







Needless to say... I added all of the coolant back into the system that I spilled on my garage floor, and started her up.

--------------------------------

Stock gauge comes online... comes up to half way point.
Defi-Temp gauge is dead at 6:00

Thermostat finally opens and I have to add a little coolant
Defi-Temp gauge is dead at 6:00

Car starts to get noticeably warm... over 200f
Defi-Temp gauge moves to about 110-120f

I have to shut the car down because it's getting to warm and the burper is starting to splash.
Defi-Temp gauge sits at about 120f.

WTF. The gauge works, it's not shorted. The lines are not plugged. Why can't I get it to give me a proper reading? I'm giving her one drive tomorrow and if the reading isn't correct, I'm going to the hardware store and I'm going to tap into the base of the housing just below low coolant sensor.

Any and all advice is appreciated.

-Rotary for the win

On a positive note, I'm getting really experienced with taking the stock battery, intercooler, ducting, ast, and other components in and out of the car.

Rotary4tw

iTrader: (3)

The more I think about it... I think I have decided what I'm going to do.

I'm going to remove my creation tonight, replace the hose with a new coolant line, and return the lower ast/radiator hose to normal condition.

Then I'm going to remove the air pump and use the tap that on the coolant filler housing for the sender. It's not quite as high as the other tap, so hopefully it will give me a good reading.



There is only one way to find out...

(Well, if somebody has used that spot they could tell me and that would be another way...)



-Rotary4tw

crosswound

You know why my gauges move way to the right only when I turn on my headlights or arm my alarm? Other than that they needle is way to the left.

Sgtblue

iTrader: (16)

Have you tried to find out why your not getting coolant through the TB hose? Seems like that might be a relatively simple fix (burping the system to remove air) and provide a easy place to put your sender.

Rotary4tw

iTrader: (3)

The only problem is that if I tap that line, and later decide to move the sender... I'm in trouble because the base of that line is about 3 hours of removal (for me) to get at.

My goal tonight is still to replace the ast/radiator line and then tap the top of the housing. I'll order an underdrive kit w/o the air/pump, and when it arrives I'll tape the side housing.

Does anybody have oil temp readings and can tell me what I should be getting during driving? (Above or below coolant temps?)

Thank you in advance.

-Rotary4tw

crosswound

At least you got a reading me, I got nothing lol. I'll keep using the search function and I have read a bunch of threads as it is, I guess i'll just keep reading.

Sgtblue

iTrader: (16)

I had the same concern, but I just added a 2 inch section of hose (~$1 from the auto parts store), using that and the factory end of the stock TB line to put the 'T' in.
But I'll stop nagging ya now.

rockshox

iTrader: (3)

there is no such thing as a seperate ground wire, all grounds go to the same point. Its highly unlikely the gauges draw enough current to cause a voltage drop in your shared ground wire. Make sure your ground is going to the chassis and not the interior lighting ground wire.

CantGoStraight

I used this spot (just to the right of the level sensor) turns out it's the exact same spot the factory uses for the Automatic transmission water temp sensor for the Auto ECU.

CantGoStraight

Two of your choices have very little flow through them. The one near the fire wall (to your TB) may be clogged as it is when it open not much coolant flows through there and when people bypass the thermowax unit they don't put a restricter in the hose (about the same size as the thermowax unit) and it winds up being a bypass. Same with the AST I believe it's the bottom hole that has abiult in restricter in it as well as to not act like a bypass. The thermostat housing is one of the better choices and if your getting rid of the air pump then the pipe threaded hole on the left will work fine and no need to drill and tap the housing. Hope you get it figured out. Jack

bros0000

The A/F gauge doesn't read richer than stoich even when you're really on it? At low load the ECU goes into closed loop mode and uses the O2 to find the optimal A/F for good gas mileage. So during that mode the needle will be bouncing wildly back and forth. When you really get on it, it should go richer and stay that way until you get back off the pedal.