Does ECM use O2 readings in WOT?
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Supreme Member

Joined: Jul 1999
Posts: 1,466
Likes: 71
From: Alberta, Canada
Car: 1989 Camaro-1LE
Engine: TPI(s)
Transmission: 5 speed (MM5, MK6)
Axle/Gears: 3.45, 3.73
Does ECM use O2 readings in WOT?
Just curious if the ECM is able to compensate for rich/lean condition in WOT. I recall reading it did not use the O2. Thus if your running lean, you are risking some engine damage.
Is this a better question for the PROM board?
Mark.
Is this a better question for the PROM board?
Mark.
No compensation. The stock narrow band O2 sensor is of the switching type and does not have sufficient resolution away from stoichiometric (rich or lean) to be used for closed loop mixture control at WOT.
Thread Starter
Supreme Member

Joined: Jul 1999
Posts: 1,466
Likes: 71
From: Alberta, Canada
Car: 1989 Camaro-1LE
Engine: TPI(s)
Transmission: 5 speed (MM5, MK6)
Axle/Gears: 3.45, 3.73
That's what I thought.
So the only way to know for sure if you running rich or lean is to put it on a dyno with a wide band O2? Or else spend hours at the track burning chips and checking your times.
This also explains why TPIS saw more HP when then simply adjusted the fuel pressure on a stock PROM setup. The early TPI's were setup to run rather lean in WOT.
I've always planned to go down to the chasis dyno. At least this is another reason to spend the money.
Mark.
So the only way to know for sure if you running rich or lean is to put it on a dyno with a wide band O2? Or else spend hours at the track burning chips and checking your times.
This also explains why TPIS saw more HP when then simply adjusted the fuel pressure on a stock PROM setup. The early TPI's were setup to run rather lean in WOT.
I've always planned to go down to the chasis dyno. At least this is another reason to spend the money.
Mark.
Thread Starter
Supreme Member

Joined: Jul 1999
Posts: 1,466
Likes: 71
From: Alberta, Canada
Car: 1989 Camaro-1LE
Engine: TPI(s)
Transmission: 5 speed (MM5, MK6)
Axle/Gears: 3.45, 3.73
I've done that for year ... and have the scars to prove it! I've always had a hard time reading the plugs. It seems like such a faint line on the plugs. Granted if they are black, then that is easy.
I figured I might try this technology thing for a change.
Seriously though. I have always had plans to go to the chasis dyno, more for fun than anything else. But if I can get a A/F reading at WOT, that should tell me what I need to do with the fuel curve. I suspect today that I am running lean at WOT, but in everyday driving, the BLMs are fine, mileage is great. Then again, maybe everything is OK. I'd just like to know for sure.
Mark.
I figured I might try this technology thing for a change.
Seriously though. I have always had plans to go to the chasis dyno, more for fun than anything else. But if I can get a A/F reading at WOT, that should tell me what I need to do with the fuel curve. I suspect today that I am running lean at WOT, but in everyday driving, the BLMs are fine, mileage is great. Then again, maybe everything is OK. I'd just like to know for sure.
Mark.
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