LT1 runs rough in Closed Loop
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Teching In
Joined: Mar 2005
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From: Corona, CA
LT1 runs rough in Closed Loop So I recently upgraded my engine and I’ve been working out a couple of bugs since I put it all back together. One of the last things I fixed was a problem with my Knock Sensor so that my system is no longer throwing any codes. Now that I’ve gotten rid of that code my engine can go into closed loop and as soon as it does it starts stumbling.
I hooked up TTS Datamaster to take a recording of a test run. When the engine is in open loop everything looks fine, then as soon as the system goes into closed loop the fuel trim numbers vary wildly.
So is my problem the O2 sensors or maybe the wiring to them, or could it be something else? I could post the Datamaster file if someone can read it and help determine what the problem is.
I hooked up TTS Datamaster to take a recording of a test run. When the engine is in open loop everything looks fine, then as soon as the system goes into closed loop the fuel trim numbers vary wildly.
So is my problem the O2 sensors or maybe the wiring to them, or could it be something else? I could post the Datamaster file if someone can read it and help determine what the problem is.
Thread Starter
Teching In
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From: Corona, CA
Originally Posted by Camaro_freak
It could be an intake air leak causing unmetered air to enter the engine, an exhause leak making the O2's read false lean, or bad O2 sensors.
Thread Starter
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From: Corona, CA
Originally Posted by Tony Shepherd
It almost has to be an O2 sensor issue. Are they new sensors?
Thread Starter
Teching In
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From: Corona, CA
Open Loop at low RPM??? I put on new O2 sensors, but my problem never really got resolved.
I've read that with some cams you can get false lean readings ftom the O2 sensors due to the cam overlap scavenging raw air into the exhaust. If this is true then I think the best solution may be to get my car to idle in open loop. My car runs great in open loop and in closed loop once it gets going, but it doesn't run well in low RPM closed loop.
Has anyone here tried this?
I've read that with some cams you can get false lean readings ftom the O2 sensors due to the cam overlap scavenging raw air into the exhaust. If this is true then I think the best solution may be to get my car to idle in open loop. My car runs great in open loop and in closed loop once it gets going, but it doesn't run well in low RPM closed loop.
Has anyone here tried this?
