LT1 Cutting out when warm
Thread Starter
Intermediate
Joined: Aug 2018
Posts: 44
Likes: 2
From: Apple Country WNY
LT1 Cutting out when warm
I have a '92 Vert with 52,000 miles. She has been rock solid until recently. I noticed a slightly rough idle and a little sluggishness for about a month, Recently the engine has cut out for just a second several times. Once at start up but usually upon acceleration.and only when warm. The car always has started instantly, but I also have noticed it takes just a bit longer to start when this problem is about to happen. When this happens it is as if I hit a kill switch, just a quick, abrupt shut down for about a half second and then the engine starts back up by itself. Always when warm and usually after I park it hot and restart it 1-2 hours later. It throws an CEL when it does this, but I cannot locate an OBD-1 scan tool. The CEL resets itself after the car sits overnight. If anyone has a suggestion for a starting point, I would appreciate some suggestions. I am assuming ignition or computer. The previous owner said the Opti was replaced, but had no proof of this. TIA! .
Team Owner
Joined: Sep 2001
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From: Athens AL
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The CEL code is still stored in memory, you must pull that code to make progress. No point in throwing parts at it until you know what the code says.
Autozone sells OBD1 code readers, as do most parts stores. They may have a guy who will pull that code for you.
Autozone sells OBD1 code readers, as do most parts stores. They may have a guy who will pull that code for you.
Thread Starter
Intermediate
Joined: Aug 2018
Posts: 44
Likes: 2
From: Apple Country WNY
I purchased the OBD1 reader and the code it threw is '36'. With the abrupt loss and return of power it seems more like an ignition problem than a MAF problem. The loss of engine is abrupt and total, but it is also very brief, lasting only a second or two. It starts well and runs well when not cutting out. This has never happened with the car engine cold. Any thoughts on where to start would be greatly appreciated!
Last edited by IowaClass65; May 16, 2022 at 11:01 AM. Reason: typo
Team Owner
Joined: Aug 2004
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From: Park City Utah
The Code 36 is for the opti too...adding to the "evidence". You likely need another opti.
Pro
Joined: Jan 2010
Posts: 611
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From: Olympia WA
The tach tells the story. Good observation there! The opti is dropping out. PO MAY have changed it...but buying new ones is a crap shoot. Thus, it could be new...but that doesn't mean anything, reliability wise. If your tach goes to 0 while the engine is still turning, you've lost signal from the opti....either b/c of the opti or the harness.
The Code 36 is for the opti too...adding to the "evidence". You likely need another opti.
The Code 36 is for the opti too...adding to the "evidence". You likely need another opti.
Thread Starter
Intermediate
Joined: Aug 2018
Posts: 44
Likes: 2
From: Apple Country WNY
The tach tells the story. Good observation there! The opti is dropping out. PO MAY have changed it...but buying new ones is a crap shoot. Thus, it could be new...but that doesn't mean anything, reliability wise. If your tach goes to 0 while the engine is still turning, you've lost signal from the opti....either b/c of the opti or the harness.
The Code 36 is for the opti too...adding to the "evidence". You likely need another opti.
The Code 36 is for the opti too...adding to the "evidence". You likely need another opti.
