lt1 starts then immediately dies.
08-02-2021, 01:46 PM
#1
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lt1 starts then immediately dies.
97 LT1. Just started happening about 2 days ago. It will crank, start, and then die. If you try to start it 2-3 times it will struggle to idle but then idle fine and drive fine until you try to start it again. I read it could be an icm problem and I do have a p1361 code that hasn’t ever affected anything. Any ideas?
08-02-2021, 02:36 PM
#2
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Re: lt1 starts then immediately dies.
I would imagine your ICM is on it's way out. What's the mileage on the car? Have you done the ICM cooling mod or possibly relocated it? Does it happen after warming up or when cold as well?
08-02-2021, 03:45 PM
#3
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Re: lt1 starts then immediately dies.
P1361 only sets when the engine is cranking. It sets when the PCM detects 84 crankshaft revolutions (based on signal from Opti) and there is no response from the ICM. The description is for "IC circuit low voltage". That suggests the white wire from the PCM to the ICM, the ICM connector, the contact on the ICM, or an ICM internal item is shorting. If you clear P1361, does it reappear when you are having the no start problem?
08-02-2021, 04:59 PM
#4
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Re: lt1 starts then immediately dies.
mileage is around 130k but i replaced the original icm with a cheap one online(might explain the code). haven’t done the cooling mod yet but if I end up replacing the icm again i’ll be sure to do it. not sure about trying to start it after it warms up haven’t tried that yet.
08-02-2021, 05:07 PM
#5
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Re: lt1 starts then immediately dies.
P1361 only sets when the engine is cranking. It sets when the PCM detects 84 crankshaft revolutions (based on signal from Opti) and there is no response from the ICM. The description is for "IC circuit low voltage". That suggests the white wire from the PCM to the ICM, the ICM connector, the contact on the ICM, or an ICM internal item is shorting. If you clear P1361, does it reappear when you are having the no start problem?
08-02-2021, 05:37 PM
#6
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Re: lt1 starts then immediately dies.
I've seen a few instances of cheaper ICM's not being worth a damn. I'd spring for a Delco and clean everything really good, get it off the head, apply new thermal paste and button everything up. While you're in there, check wiring to make sure it's up to snuff.
08-02-2021, 05:56 PM
#7
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Re: lt1 starts then immediately dies.
Will do. Could I get away with a non-delco icm? I work at a parts store and even with my discount the delco is $100. Would a standard ignition(bwd) icm be just as good?
08-02-2021, 06:54 PM
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08-03-2021, 08:52 AM
#10
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Re: lt1 starts then immediately dies.
Disregard my last reply. Cleared the code before starting. Started fine, but code came back about 5 seconds after starting.
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