weird event with ecm
Thread Starter
Staging Lane
Joined: Dec 2013
Posts: 80
Likes: 0
From: British Columbia CANADA
weird event with ecm So... I have been fighting trying to get my 04 LQ9 to run properly. Have aftermarket stand alone harness and computer. Motor will start..stumble and die. If I put my foot on the gas pedal it will run, rev up, and if you hold your foot on the gas pedal it will run for as long as you want. take your foot off the gas and it stumbles and stalls.
So I was doing a heat cycle figuring that maybe it needs to "learn". Because sometimes it will run for 15-20 seconds stumbling around 300 rpm. I had my scanner plugged in watching the values as I was bringing it up to temp. AS SOON AS THE COMPUTER TRIED TO TURN THE FANS ON, at 196, the stft went crazy into the negatives (-15-25) and threw a running rich code on both banks? I've had the rear O2s deleted, but my scanner reads a value of .445v and 99.4% for both of them (bank one and bank two) does that seem right?
IDEAS??????
So I was doing a heat cycle figuring that maybe it needs to "learn". Because sometimes it will run for 15-20 seconds stumbling around 300 rpm. I had my scanner plugged in watching the values as I was bringing it up to temp. AS SOON AS THE COMPUTER TRIED TO TURN THE FANS ON, at 196, the stft went crazy into the negatives (-15-25) and threw a running rich code on both banks? I've had the rear O2s deleted, but my scanner reads a value of .445v and 99.4% for both of them (bank one and bank two) does that seem right?
IDEAS??????
Last edited by mountainman; Mar 8, 2014 at 08:27 PM. Reason: more info
That means your fueling is very rich. What mods, cam specs? If your using Hp Tuner's, I can look at your tune/log. Is your fuel pressure higher that stock? Larger injectors?
Russ Kemp
Russ Kemp
Thread Starter
Staging Lane
Joined: Dec 2013
Posts: 80
Likes: 0
From: British Columbia CANADA
Completely stock LQ9 from a 2004 cadillac escalade. DBW, only mod is headers and a cold air intake. Supplier used HP tuners, but supplier wont give me a copy of the tune used, so I can only scan and guess
at that point its going from open loop to closed loop and trimming fuel like crazy because its rich , in open loop its not looking at the 02's and doesnt trim..
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I havent used my tuning software since my tuning laptop power outlet broke so I cant offer to look at your tune and my thought process regarding tuning is not as sharp as it was when using it regularly but the first change I would suggest is getting a tuner yourself or get friendly with someone local that has one so your not so tied at the hip to your tuner that you cant do anything without him that has to be a helpless feeling.
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