ICM, opti or coil problems
ICM, opti or coil problems Car starts and idles fine, once you drive it for about 10 mins it starts to stumble and randomly misfire once the revs go about 1500k. I let it cool down for a bit and it drives fine but soon starts up with the same ole ****. Sounds heat related so i picked up another icm and spaced it off the head and took it out today, drove it for about 30 mins and stopped at the mall. Got back in and get on the highway and it starts stubbling again. im at a loss the opti is a year old and sealed up tight but the coil is unknown
TECH Regular
Joined: Oct 2011
Posts: 407
Likes: 2
From: Keller Tx
Not good. I am replacing the ICM and spacing the coil today. I have the EXACT same problem and was hoping this would fix it. Michr go ahead and pick up a new coil for giggles while I am at it. This sucks!
Has it tripped any codes?
Go to www.shbox.com for the voltage readings you do on the coil, icm, and opti harness to see where you stand and where the problem resides. Do no just throw parts at it hoping to fix it.
Go to www.shbox.com for the voltage readings you do on the coil, icm, and opti harness to see where you stand and where the problem resides. Do no just throw parts at it hoping to fix it.
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TECH Regular
Joined: Oct 2011
Posts: 407
Likes: 2
From: Keller Tx
I pulled of the coil and ICM, The coil output connector to the opti looked a little pitted/cooroded. I went ahead and found a Delco on ebay and ordered it.
I have a new ICM I am putting on so I hope this is going to fix this.
I have a feeling not. I do throw the random misfire code once in a while when it is running rough.
I have a new ICM I am putting on so I hope this is going to fix this.
I have a feeling not. I do throw the random misfire code once in a while when it is running rough.
I wont get missfire codes since im obdI but im gonna take everything off double check the grounding points and go for a ride and test the coil if it starts acting up. I did hook up my wideband today and take it out and when it was started missing it leaned out like around 17.1 then back the normal then spike to lean again
Dude did you read what i just posted. Why are you throwing money and parts at it if you dont know what the problem is??? Do the voltage tests and see what is actually bad! Very simple to do and your no stressing yourself and wasting time and money on parts that may not be the problem!
TECH Regular
Joined: Oct 2011
Posts: 407
Likes: 2
From: Keller Tx
Dude did you read what i just posted. Why are you throwing money and parts at it if you dont know what the problem is??? Do the voltage tests and see what is actually bad! Very simple to do and your no stressing yourself and wasting time and money on parts that may not be the problem!
Thanks for all your help!
To be honest and alot of folks on here agree to the comment "if it works dont touch it" when dealing with lt1s. Sometimes aftermarket coils, icms, etc can make it worse as there **** quality. Do the simple voltage tests to find the problem is and stop beating around the bush its very simple and will tell you wtf is actually going on. Maybe im just retarded for trying to help solve your problem cause you dont seem to be listening.
TECH Regular
Joined: Oct 2011
Posts: 407
Likes: 2
From: Keller Tx
To be honest and alot of folks on here agree to the comment "if it works dont touch it" when dealing with lt1s. Sometimes aftermarket coils, icms, etc can make it worse as there **** quality. Do the simple voltage tests to find the problem is and stop beating around the bush its very simple and will tell you wtf is actually going on. Maybe im just retarded for trying to help solve your problem cause you dont seem to be listening.
To be honest and alot of folks on here agree to the comment "if it works dont touch it" when dealing with lt1s. Sometimes aftermarket coils, icms, etc can make it worse as there **** quality. Do the simple voltage tests to find the problem is and stop beating around the bush its very simple and will tell you wtf is actually going on. Maybe im just retarded for trying to help solve your problem cause you dont seem to be listening.
TECH Enthusiast
Joined: Aug 2010
Posts: 543
Likes: 0
From: New Hampshire
Any clue what the o2 sensors are doing during the stumbling? Do you have a way to datalog the car?
Honestly, having a laptop and buying the aldl cable is the way to go. Scanning the car takes 3 seconds and no more guessing at what COULD be wrong, its usually very obvious.
.02
Sounds closed loop related based off that.
Honestly, having a laptop and buying the aldl cable is the way to go. Scanning the car takes 3 seconds and no more guessing at what COULD be wrong, its usually very obvious.
.02
Sounds closed loop related based off that.
Do the voltage checks to verify everything is fine cold. Once it acts up do it again. Those harness's are very easy to get to. Im thinking more if its not icm heatsoak that its your fuel pump on its way out or the relay is going bad. Buddy of mine had the same issue when it got hot it would do the same. Turned out his fuel pump relay was getting hot and causing it to go lean and want to stumble and barely run then die.
Any clue what the o2 sensors are doing during the stumbling? Do you have a way to datalog the car?
Honestly, having a laptop and buying the aldl cable is the way to go. Scanning the car takes 3 seconds and no more guessing at what COULD be wrong, its usually very obvious.
.02
Sounds closed loop related based off that.
Honestly, having a laptop and buying the aldl cable is the way to go. Scanning the car takes 3 seconds and no more guessing at what COULD be wrong, its usually very obvious.
.02
Sounds closed loop related based off that.