Installing A/F Gauge

[Mike's89AccordLX]

Alright I think I have a pretty good idea on how to do this, but I just want to make sure I have it right. I have the Autometer Air/Fuel Gauge #4375. It has a purple wire (goes to O2 sensor), red wire (positive wire), and a black wire (ground). I'm going to buy some wire loom and a 5amp fuse holder to have a fuse on the red wire. I'm going to hook the red wire up to a yello wire under the dash. Is any yellow wire sufficient? (I was also told a black wire w/white stripe would work). I'm going to follow the O2 sensor wires to a place that would be easy to tap into with the purple wire. I guess I will just tap the ground wire into any ground wire that's easy to get to.

[A20A1]

Tapping the O2 sensor wire doesn't work too well... I'm sorry if I mentioned to do that.
Just unplug the O2 sensor and use bullet connectors... near to the lower front motor mount. That way you can swap between using the guage and letting the car use the sensor.
If you have them both connected the drop in the voltage signal is significan't enough that you'll get funny readings.

I would wait to double check before connecting the red wire to a suspected On with ignition wire. I never used one from under the dash thats why.

[A20A1]

Another option is hook the red wire to a seperate on/off switch and connect the red wire to the battery. then put the fuse as close to the positive terminal as you can. maybe like 3" is good.

[Elijah]

I got the air/fuel by autometer part#3375 but mine has the same color wires I was wondering how to hook it up just never had time to check it out yet.

[Mike's89AccordLX]

I have no idea what bullet connectors are Mike. I like the idea of having an on/off switch. I'll talk to some shops tomorrow for advice. I want to install this tomorrow.

[Elijah]

Mike's89 is yours the same as mine just with difforent part #

[Mike's89AccordLX]

yeah I think so.

[Mike's89AccordLX]

Where would a good ground connection be? I was thinking maybe I could hook it up to the valvecover. I'm confused now on the O2 sensor now. Bullet connectors?

[Elijah]

You could ground it to almost anything find something nere where ur mounting it.

[A20A1]

I grounded my wire to the intake manifold close to the fire wall. there were plenty of holes for a bolt after i removed all the vacuum crap.

the valve cover may be a better choice. you'll just need a longer wire.
anywho a bullet connector is sort of like a spark plug wire and a spark plug, in the way that they connect together.

[Mike's89AccordLX]

Is there these bullet connectors at the other end of the O2 sensor? Like in this picture there was the O2 sensor then on the other end there were 3 little things. Are those bullet connectors? Or do I have to buy them? Should I just find the same size wires if I need to extend them? I still don't really understand where you want me to hook up the purple wire. Thanks for all your help.

[A20A1]

wait never mind it uses a regular plastic clip connector.
what you should do it cut off the plastic connector, leave about 1" of wire with the connector. then strip the wire on the O2 sensor side and add one side of the bullet connector... go to radio shack and tell them you want one and they will point it out.

the other side of the bullet connector you add to the purple wire. then you just plug the O2 wire into the Purple wire.

You'll need a crimping tool or a pair of pliers to crimp the bullet connectors to the wire. You'll also need a wire stripper or a knife to strip the insulation off the wire from the area you instert into the connector.



If you want to be simple just strip the ends and splice the wires together, but the other way is much cleaner and has less chances for the wire to break apart later on.

[A20A1]

Anyways this is what a bulletconnector is.
2 metal connectors one female the other is male
and they have a plastic casing.
on the other end they each have a crimping part that you stick your striped wire end thru so you can crimp the connector on.

[2old_honda]

you might want to get a new o2 sensor for a more accurate reading. (assuming the one on your car is the original, or several years old)

[2old_honda]

Do not run a wire all the way into the engine bay for the ground. that is completely unnecessary. If you did that you will run the risk of picking up outside "noise" that could affect your gauges accuracy. Find a bolt under the dash that is connected to the fire wall, sand off the paint underneath it to expose the bare metal and crimp on a connector that you can bolt down under the bolt.

For the o2 sensor wire use a shielded wire directly from the o2 sensor all the way up to the gauge for the best possible accuracy. Keep the wire away from the cap and spark plug wires.

[Mike's89AccordLX]

Alright, I have some of those bullet connectors. Just didn't know they were called that. Ok lets see if I understand it all now... I cut that plastic connector off (I know what that is :)) And then I splice one of the wires. (which one is the O2 wire? When I put my headers on it looked like 2 wires together) And then put a bullet connector on the wire closest to the O2 sensor. Then put the other side of the bullet connector on the purple wire and connect them. I plan to get some wire loom probably 1/16" or 1/8" (I'll have to see them first) What I don't understand still is what do you do with the other wire (O2 wire). Do I just leave it or tap it up and leave it. And about 2 years ago I did have a new O2 sensor installed as well. I plan to do the switch idea A20A1 suggested b/c then I won't have to mess with wires under the dash. When I was messing around in the engine I did see that there was a place on the manifold for me to put the ground wire. Would that be ok or is that too hot? I'm custom making a gauge holder. PVC pipe (not like in the how-to's though) It has a 90 degree bend and has a little extension that fits the gauge perfectly. I used my heatgun and heated up one end and made a lip big enough to put screws in it. Now all I will have to do is mould it to the A-pillar and paint it. Oh and put some Autometer stickers on the PVC pipe so it doesn't look weird.

[A20A1]

Having the wire on the engine would put less distance between the sensor and the guage, but do keep it away from the battery coil and spark plug wires, and don't use the same ground location as other wires.

As for sticking it on the manifold
The heat will add resistance... but there wasn't any difference when I connected it near the drivers side strut tower

[89accordlxi]

Where are you guys getting the A/F guages at? I'm looking to buy one but don't know where.

Peace

[Mike's89AccordLX]

I got the part # from autometer site and went to a local shop and bought it there. I bought 10' of wire loom, 5 amp fuse holder w/fuse, switch with little led, 25ft of 22 gauge wire. What my question is, I will have to extend the purple wire to go to the O2 sensor, what wire will I use to extend that? Can I just use the same type of power wire that I'm using to go to the battery? I looked in the haynes manual for info on the O2 sensor and I still need to know which wire I have to use ( I think there are two wires ) Thanks again.

[Mike's89AccordLX]

Alright I looked at the sensor and there is one wire. So that answers one of my questions. I think I have everything I would need to install this now. I think I have one more question inaddition to the purple wire extension, do you drill into the A-pillar or what? How do you hide the wires inside the car.

[Mike's89AccordLX]

Alright I just got done with sanding the PVC pipe that I have. I just realized that I need to get some self-taping screws. What length of screws do you guys suggest?

[skaterjunky8]

What O2 censor do you tap into? Is it the one on the header? If so which one is it if you have two?

[Mike's89AccordLX]

You don't tap into it I guess. Your supposed to cut it and hook the A/F gauge wire up to the wire that goes to the O2 sensor. I think the FI models have two sensors and I don't think it matters what sensor you use but I would ask someone that has a gauge that has a FI model accord. And yes it is the one on the header.

[2old_honda]

I dont understand why you guys are grounding stuff to your engine. The ground wire should be as short as possible for the least resistance (close to the gauge). Ground the gauge inside the car, not in the engine bay! It is the same principal as installing audio amplifiers, a short ground connected directly to the chassis.

[Mike's89AccordLX]

Well I have to ground the gauge and my led switch. I'm going to look for places under the dash.

[2old_honda]

If I were you I would connect the power to a switched +12v (power is on when key is on, power is off when key is off) that way you wont have to worry about turning the gauge on/off.

or if you want to connect it directly to the battery, use a relay to turn the power to the gauge off/on when you turn off/on the car.

[Mike's89AccordLX]

Yeah I know that would be better but, I am new to wiring stuff. I really haven't done any work with wires before. I don't mind turning a switch on and off I do it with my radar detector. It just seems easier to me this way. Anyone know if I can just extend the purple wire with a normal power wire thats the same size and voltage?

[Mike's89AccordLX]

Oh I forgot to add one more thing to my list of supplies.... ALCOHOL!!!!!! It's not good to mod your car without it.

[A20A1]

You can use a larger wire... I think I ran a 18 or 16 guage to the sensor.

[Mike's89AccordLX]

Cool, does anyone know how to get the a-pillar off though or do you just drill a hole in it and run wire down it and hopefully it comes out?

[2old_honda]

I will go out and check, I will be back in like 30 min. I will also check something for a easy power connection, I know integras have it I wonder if our accords do too.

[2old_honda]

to get the a-pillar off you just have to pull it, it is just held in with little push clips behind it. be carefull with it, it is brittle and can crack easily.

for the power-
our cars have a +12v switched power tap built into the fuse box. you just need to put a female spade connector on the tap and you are done. here is a picture of where to locate the tap.

http://www.o-t.us/upload/guest/diag.jpg

the tap is labled on the fuse box 1 2 3 right above each connector. you should use connector 1 (the one on the left). All you have to do is plug one of these into the little connectors (the red slot in the first pic)//www.radioshack.com/images/ProductCatalog/ProductImage/64/64-3039.jpg(I think it is called a spade connector but I might be wrong) You will still need the inline fuse. This is a switched tap, so the gauge will come on/off when you turn the car on/off. You could still put a switch in line so you can turn the gauge on/off but it will only work when the key is turned.

I know that is confusing, but when you see what I am talking about on the fuse box you will understand what I mean.
If you have any questions please ask me.

[Mike's89AccordLX]

Hmm... I think I understand I have seen the fuse box before but didn't know what those were. I'll check it out. That doesn't seem too hard to do. I tried pulling on the A-pillar and nothing happend. Is there a special spot I need to pull from? Thanks for the pics, I get my gauge pillar in Thursday ( I gave up on making a custom one, so I ordered a 80-90 CRX 2 pod pillar. Just have to do some handy work with the heat gun.

[2old_honda]

The a-pillar should just pull off. I started pulling by the corner of the windshield, but I dont know if it matters. Just be careful, it is really easy to crack it.

[Mike's89AccordLX]

I tried messing with it for about 2 minutes and I couldn't get it to come off, but I have today to try and pull it off. I get my accel jet ( 60 ) for my weber today and my weber book so I might be preoccupied. I'm sure I can get it off though.

[Mike's89AccordLX]

I finally got the mofo installed and it works terrific. I used the pic that 2old_honda posted and I got it on in under an hour and a half (lots of distractions though) Now I just need help installing my accelerator pump jet (60) I have the book and can't find the page anywhere.

[Mike's89AccordLX]

Ok after letting it idle for about 10 minutes the gauge doesn't light up anymore. And I restarted it and it lights up a little and it falls below lean and doesn't light up anymore. This guy I called said it might be the O2 sensor. But I just replaced one 2 years ago.

[A20A1]

The sensor needs to be hot in order to work right.

also you may want to adjust the air fuel mix screw at the back of the carb... make sure you know where it was set at when it came out of the box before messign with it. use the weber book... it tells you a good way to adjust the mixture screw.

also when you press the gas does the guage rise?

and make sure your throttle isn't set too high... if the plates are way open then you won't be using the idle passage below the throttle plates... and adjusting the idle mix screw will show little results.


but then it could always be a bad o2 sensor.

[Mike's89AccordLX]

My idle screw is screwed in like all the way and the a/f screw is screwed out rich. It's like the only way the car will run decent. I talked to the guy again and he told me to call autometer. So most likely the throttle is set too high.

[Mike's89AccordLX]

When the gauge is somewhat working the lights do rise up a little but if I let it idle then the lights disappear. I remember when I was trying to get the carb to WOT I pulled out some more throttle cable because the shop cut it and it was really short and frayed so I couldn't get it back in the little hole so I had to cut it and put it back in and pulled it tight.

[Mike's89AccordLX]

I have the emissions tubes on my headers plugged, that wouldn't affect the readings would it? I emailed autometer and waiting for a reply.

[A20A1]

having the emissions tubes connected and working would affect the readings... it would knock the guage to low lean.

anyways... it's probrably just a dirty O2 sensor... if it can't get the voltage signal then nothing will show up on the guage. The guage is not faulty if thats what you want to hear.

as long as it reads off idle you are fine... thats where you need it to work anyways.
@ idle you can usually tune it by ear... especialy with a stock cam in.

[Mike's89AccordLX]

It doesn't constantely light up like it should. I found out that when I press on the gas pedal and let off, that's when it lights up. I didn't ever think that it was a faulty gauge I just thought something I did was bad. I always have tuned it by ear. If the O2 sensor was dirty or whatever it would light up off and on wouldn't it? It wouldn't read it constantely, that's what I think. And when you mentioned about that it could be dirty, it reminded me when I installed the headers a month ago... the sensor looked kinda dark grey. (or greyish black) I thought it was normal maybe it's just bad. I'll probably order a new one from nopi for $19.00 or so. Do you think that's the case? I am leaning towards that b/c the gauge wouldn't at all if any of the wiring was wrong of bad.

[2old_honda]

try a new O2 sensor

[Mike's89AccordLX]

I got an email back from autometer and they said, "that 1 wire O2 sensors give bad readings and that I should buy their O2 sensor kit for $126.00." I plan to just buy that bosch one on nopi for $19.00 what do you guys think I should do? Don't your gauges work fine with a 1 wire O2 sensor?

[A20A1]

From: Rob Robinette

How the O2 Sensor Works

The oxygen sensor detects oxygen in the exhaust in a way similar to a battery cell. Platinum layers on the inside and outside of the probe act as electrodes. Zirconium dioxide between the layers of platinum acts as an electrolyte. The inside layer of platinum is exposed to the air in the engine bay, the outer layer is exposed to the exhaust. When the O2 sensor is hot it generates positive voltage between the two layers of platinum. Negatively charged oxygen ions in the exhaust are attracted to the platinum and reduce the voltage that the Engine Control Unit and air/fuel gauge reads.

That's why a rich mixture = higher voltage from the sensor (more gas = fewer negative O2 ions to drop the voltage) . Just remember "L=L", Lean = Low voltage. You can attach a Volt Ohm meter (black to ground, red to the O2 sensor) to monitor your engine's air/fuel ratio. Full throttle with 0.82 volts is best performance but slightly higher voltage (richer) is safe. At part throttle the ECU will bounce the ratio from rich to lean. You only have to worry about full throttle. I suggest you have a copilot read the voltage while you accelerate at full throttle.

The 3 wire sensors are used to give power and ground to pre-heat the sensor so it starts working quicker, it has no effect after the sensor gets warmed up.

___

The sensor does not begin to generate it's full output until it
reaches about 600 degrees F.

[A20A1]

Oh and while you are installing the accel jet please write down the sizes for the other jets...

Main (primany / secondary)

Air correction (primany / secondary)

Idle (primany / secondary)

[Mike's89AccordLX]

Will I see those when I install it? I'm going to take some pics of me doing this soon and some pics of just the 60 jet. I was reading in the book last night and think I have it pretty much figured out. Do you think that the jets would be different from yours?

[2old_honda]

If the gauge is still acting weird after the car is fully warmed up then try a new O2 sensor (hey its only $20). What auto parts stores do you have near you? Most will have that same bosch sensor for $15-$20 (and you wont have to pay shipping).

just tell me what local auto stores you have and I can look up the price for you.

[Mike's89AccordLX]

I have NAPA autoparts store, Champion Autoparts, Big A autoparts, and some others too.

[A20A1]

Page 56 - 61 of the book shows you the jet locations...

Idle jets are #33 on the diagram and are held by #35 which screws into the front and rear of the carburetor.

the main jets are #19 on the diagram and srew in at an angle near the bottom of the float bowl

the air correction jets #94 sit inbetween the float bowl and the carb barrels.

and # 96 is the accel jet which sits almot between the 2 air correction jets.


Now the air correction jets is labled on the top ner the slit for the screw driver so you wont have to remove them.

The main jets are labled on the side of the jet so you must unscrew them to read the #'s

the idle jets must be unscrewed but you don't need to remove them from the holder since they are also labled on the side.

be careful not to sratch the jets when removing and reinstalling them.

[Mike's89AccordLX]

Alright Big A was $22 and in stock for standard products inc., Champion had me on hold for 13 minutes and I just hung up, NAPA was $26 and they need to order it. I'll just pick it up tonight, i'm sure it will be just as good as a bosch.

[A20A1]

Bosch was the first to make O2 sensors.... Lambda sensors... whatever.

[2old_honda]

napa has them for $24, The Champion site is down, and Big A dosent have a site.

NAPA is always expensive, I would go to champion or big A. I know that the stores where I live (not including NAPA) have them for $18, I am willing to bet that champion will have it for under $20

[Mike's89AccordLX]

I'll called them and they want $25 for it and the guy didn't even ask if it was carbed or fied, or what size motor I had. So I'm not going there. What I'll do is buy the Big A sensor and when I get to it I'll clean the old one and see if it works and if it doesn't I'll put the new one in.

[2old_honda]

:cool: good luck. I hope you can get this thing going.

[Mike's89AccordLX]

Alrighty, I just got the part home and I open the box and it has about a foot of wire and a butt connector on it already. The connector is for 14-16 and my wire is a 22. Is this going to cause a problem? What size wire did you guys use? I just found some wire at radio shack that was the same size as the gauge's wires. Could that be a problem that I am facing now (current changes?) Or is it fine to just use different wire connectors that will work with the 2 sizes of wires. I have some bullet connectors for a 14-16 and I have them for a 22.... maybe I should just use the 2 different connectors. Cause right now I have a 14-16 wire going into a 22 connector. Thanks again guys.

[2old_honda]

if the two different connectors fit into eachother use them. but if the 14-16 wire going into a 22 connector is a good solid connection then it will work too.

[Mike's89AccordLX]

Alright, I was worried that the two different sizes would matter or affect the readings. I'm going to put the new O2 sensor in tomorrow.

[2old_honda]

it wont affect the readings, just make sure all of your connections are good and solid. wrap the connections with electrical tape or heat shrink to make sure water and crap does not get into the connection.

[Mike's89AccordLX]

I have these water proof connectors, but I do wrap every connection with electrical tape. It's really cold here and I might have to wait a little while until I can find a place to do it.

[Mike's89AccordLX]

Alright now I'm having problems with getting the old O2 sensor off. I don't want to take off my headers, so I'm thinking if I use my dremel to cut off most of the old sensor off I could fit a socket on the sensor and get it off what do you guys think?

[Mike's89AccordLX]

Alright I have the new sensor installed and it's still not working right. This is what happens, when I'm driving and I press on the gas nothing lights up and when I let off the gas that's when it lites up and gives me the readings. This sensor I put in is made out of platinum so it must be pretty good. What do you think could be causing the gauge to be acting that way? Could it be a bad ground, or would the gauge not work if it was a bad ground. I really appreciate your guy's help with this gauge problem. I'm new to wiring so I'm clueless right now.

[MoonScryer]

I know others will disagree with me on this, but I had to run the ground wire all the way to the battery to get the gauge to read correctly (the power was from the 12v connectors on the fuse block under the dash). Since my o2 sensor sits right below the firewall (I had to move it since I only have one, and it was only reading two cylinders), I have a really short lead on the purple wire.

I did try a bolt under the dash, the engine block, the bolt on the shock mount, etc, etc., but everytime you turn the lights on or any electrical device, the reading went down into the lean side a corresponding amount - more accessories/electrical stuff on, the more it went into lean. After hooking it to the battery, the interference was gone mostly.

Hook the ground up to the battery - use copper multistrand wire, 16 gauge - and see if it reads a bit better then. It will not read right until it warms up, but if I'm right, it will. Also think about doing the power the same way, w/ a relay in between, and run the relay's open circuit wire to the power on side of some ignition source. Clean power, no switch.

[Mike's89AccordLX]

Thanks a lot for the advice. I was thinking that maybe the ground was bad. I'll try that and hopefully it works like it's supposed to. I have a 22 gauge ground wire that I could use. I should invest in some of those nice battery terminals for sound systems. If anyone else has some more advice please let me know. I'll keep you guys posted on whats going on.

[2old_honda]

you used that connector on the fuse box for the power right? you put it on connector# 1 correct? try using connector # 2 (the one in the middle) and see if that helps. *note- It probably wont fix anything but its possible.

Also make sure that you have a good ground. (make sure that you sanded the paint down to bare metal under the bolt that you used)

If none of that helped run a 18-16 gauge power wire directly off the battery and see if that does anything.

[Mike's89AccordLX]

I did use power slot one and I will try #2 tomorrow. Thanks for the ideas.

[A20A1]

Originally posted by Mike's89AccordLX
Alright I have the new sensor installed and it's still not working right. This is what happens, when I'm driving and I press on the gas nothing lights up and when I let off the gas that's when it lites up and gives me the readings. This sensor I put in is made out of platinum so it must be pretty good. What do you think could be causing the gauge to be acting that way? Could it be a bad ground, or would the gauge not work if it was a bad ground. I really appreciate your guy's help with this gauge problem. I'm new to wiring so I'm clueless right now.


You need a bigger idle jet perhaps.

Letting go of the gas increases vacuum when the throttle closes and the engine speed is still high. The increased vacuum pulls out more gas from the carb... and the air restriction causes the mixture to get richer. So thats what your guage is picking up.

What gets me worried is that the guage doesn't rise when you press the gas... but with the 60 pump jet it should go up.

[Mike's89AccordLX]

I'm a little tight for money right now b/c I'm going to Mazatlan, Mexico on Friday the 28th. I need lots of alcohol money b/c I'm going to be there for 10 days. My parents have a time share down there at this resort. But, I remember you wanted me to list my jet sizes when install the accel pump jet. Are all the other jets right in that same area? And what other jets do you think I should purchase in the near future. My birthday is in April on the 20th so I'll have some more big cash rolling in here soon. I found out my girlfriend bought me Metallica concert tickets for this summer here in MN. It's snowing here so I will try to run the ground to the battery and switch the power plug thing.