1990 GSX - EGT Gauge going Full RICH!

[GSXlaunch]

The past couple of times I have driving the car the egt gauge has been stuck on the last green light meaning it is full rich. This only occurs once the car has been driven for a while, otherwise it works fine. I am trying to figure out what is causing this. Perhaps it is a simple connection problem. I did notice that my logger shows O2 FT at 100% as soon I start getting on it. If I am just cruising, FT% fluctuates normally but as soon as I start to give it more gas it goes right to 100% and stays stuck there. My fuel trims are as follows:

low = 81.2%
med = 98.4%
high = 85.1%

I am running boost at about 10-12 psi right now but want to up that to 25+ pretty soon. I've got the stg 3 chip with injector comp for 780cc's. I've got my GM Maft trans set to read 450cc injectors. My AFC is set to the following:

800rpm = -8
2400rpm = -10
4000rpm = -12
5600rpm = -12
7400rpm = -4

I am not seeing any knock at all and the car actually is driving pretty good even tho it is running a little rich.

 

[JiggahMan]

How would an EGT gauge tell you if you are rich or not??

 

[project_tsi]

How would an EGT gauge tell you if you are rich or not??

I think he has it mistaken w/ a Air/ Fuel guage.

 

[superdaddy]

doesn't high egt gauge readings mean its running lean.....

 

[project_tsi]

doesn't high egt gauge readings mean its running lean.....

It Can, or it cant. He did mention that his last green light was on, meaning that its a a/f guage. EGT gauges have needles and use the full sweep guage.

 

[project_tsi]

The past couple of times I have driving the car the egt gauge has been stuck on the last green light meaning it is full rich. This only occurs once the car has been driven for a while, otherwise it works fine. I am trying to figure out what is causing this. Perhaps it is a simple connection problem. I did notice that my logger shows O2 FT at 100% as soon I start getting on it. If I am just cruising, FT% fluctuates normally but as soon as I start to give it more gas it goes right to 100% and stays stuck there. My fuel trims are as follows:

low = 81.2%
med = 98.4%
high = 85.1%

I am running boost at about 10-12 psi right now but want to up that to 25+ pretty soon. I've got the stg 3 chip with injector comp for 780cc's. I've got my GM Maft trans set to read 450cc injectors. My AFC is set to the following:

800rpm = -8
2400rpm = -10
4000rpm = -12
5600rpm = -12
7400rpm = -4

I am not seeing any knock at all and the car actually is driving pretty good even tho it is running a little rich.

Those fuel trims are OK, however I would actually richen up the low and high a tad. 80-100% is where you want to be, but your cutting it a little close w/ the 81.2% and 85.1%. Also lots of people will tell you that a A/F guage is mearly nothing more than a cool little light show. A Proper working true EGT guage will tell you how your car is running, rich or lean, at any given time. Whereas a A/F guage only will tell you mixture that your computer "thinks" you are getting. My A'F guage reads rich all the time, but I know it runs good, according to my logger, and EGT guage.
Hope this helps.

 

[JiggahMan]

Those fuel trims are OK, however I would actually richen up the low and high a tad. 80-100% is where you want to be, but your cutting it a little close w/ the 81.2% and 85.1%. Also lots of people will tell you that a A/F guage is mearly nothing more than a cool little light show. A Proper working true EGT guage will tell you how your car is running, rich or lean, at any given time. Whereas a A/F guage only will tell you mixture that your computer "thinks" you are getting. My A'F guage reads rich all the time, but I know it runs good, according to my logger, and EGT guage.
Hope this helps.

So, you're telling me timing has NOTHING to do with what the EGT gauge reads??

 

[Mits3gts]

wouldnt he want to LEAN out the lows and highs???

 

[DSMTalonAWD51]

egts dont tell you anything except whether or not your car is pulling timing and that doesnt necessarily equate to running lean.

 

[Defiant]

EGT=Exhaust Gas Temperature. A thermometer.

A/F Gauge=pointless blinky lights, unless you sink half-a-thousand into a wideband sensor and reader.

Come on back when you figure out what you're talking about.