running rich

[bstevenson]

Hey guys I just bought a new (to me) 91 supra T the other day. It has the following mods:

3" turbo back exhaust (no cats)
K&N Intake
Light weight Fidanza flywheel
ARP Headstuds/bolts
1.2 MM MHG
HKS Fuel Cut Defender
Aftermarket Boost Gauge
Air/Fuel Gauge

On the way home from picking it up, the car was running really rich. The a/f gauge wasn't working, but I could smell the fumes inside the car. It is not throwing codes or anything either.

Today the car isn't running rich enough to where I can smell it or anything so it may be running to spec, not sure. But I was looking at the wiring on the a/f gauge and trying to follow them to see how it was hooked up and when i started my car back up the gauge was working. It was going haywire though, just bouncing back and forth across the board. Now there are 3 wires coming out of the back of it. Purple, red and black. The purple wire is spliced into one of the o2 sensor wires and I didn't follow the red and black because I would assume that those are power wires. If anyone has any clues what is going on with this gauge please let me know because I'd like to get it working right so I can keep an eye on my a/f ratio. Any ideas or questions that you may have that would help figure this out would be great.

 

[robbo185]

if its a generic a/f gauge like autometer...its just a light show...it really doesnt do anything...the purple wire should be spliced into the blue wire if i remember correctly. Do you have an aftermarket bov?

 

[bstevenson]

It is an autometer, the purple is spliced into on the other side of the connector where the o2 sensor hooks up. It's spliced into the yellow I believe. No it's stock bov, I'm about to buy intercooler, bov and bend some custom hardpipe, but I wanna make sure theres nothing I need to fix before spending money on more mods.

 

[robbo185]

i would not buy that stuff yet.....rule number 1 for modding a supra.....make sure the engine has the general maintenance done....spark plugs, vaccuum lines, oil change...etc etc....dont want to spend money on other mods and have something go wrong..

read the modding faq in the reference section...it will help alot

 

[GreenChevelleSS]

the a/f guage I hooked up had purple/black/red/white
Purple- O2
Black- ground
red- Power
white- Guage light/headlight switch

They are hard to understand with the light show but do show what you are running. there should be an instruction manual that will explain everything

 

[bstevenson]

Yeah, I just bought oil/filter, new belts, ngk plugs/wires, i'm gonna get new hoses and replace all them first, but still confused on this a/f gauge even if it is a generic one, it should work to some extent if it was hooked up right. Think I should splice it into the blue wire and repair the yellow? Want to be sure everything IS in good working order before I spend any money on more mods.

 

[bstevenson]

Which wire did you hook your purple to? Did you hook it to the blue coming from the o2? That could be the problem w/mine. I don't have an instruction manual, it was all installed by a previous owner

the a/f guage I hooked up had purple/black/red/white
Purple- O2
Black- ground
red- Power
white- Guage light/headlight switch

They are hard to understand with the light show but do show what you are running. there should be an instruction manual that will explain everything

 

[GreenChevelleSS]

The car i put the gauge on had a 1 wire o2 sensor but if I recall i think it was purple or blue... cant remember for sure..

 

[JAB89]

It was going haywire though, just bouncing back and forth across the board.

This is normal when just crusing. ECU is constantly correcting, cycling around STOICH. Light show will sweep back and forth between Lean and Rich. It's called cross-counting.