OBD1 Diagnostic
05-20-2018, 03:46 PM
#1
Cruising
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OBD1 Diagnostic
I have an OBD1 scanner but I'm struggling on understanding the check engine light codes as the thing just flashes and you have to decipher what the hell it means. I took a video of it but it is to large of a file to upload here. Would anyone be willing to help?
So far I have replaced plugs,wires,fuel pump as it was bad, fuel filter. Cap rotor. Running out of ideas.
Last edited by Todd Davis; 05-20-2018 at 04:07 PM. Reason: Adding a vid
05-20-2018, 04:02 PM
#3
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05-20-2018, 04:11 PM
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Melting Slicks
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Googled this.. Hope it helps.
http://www.neilkline.com/Tech%20Tips/obdcodes.htm
https://www.obd-codes.com/trouble_co...igit-codes.php
http://www.neilkline.com/Tech%20Tips/obdcodes.htm
https://www.obd-codes.com/trouble_co...igit-codes.php
05-20-2018, 04:20 PM
#7
Melting Slicks
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PS: If you don't know any of this and you are new to it all, one of the single best investments you can ever make in a corvette is either a Factory Service Manual, or a subscription to alldata dyi.
https://www.alldatadiy.com/
Cause there's tons of info in there..
C4's are horribly confusing. They have all the tech new at the time, and none of the advance diagnostics that came later.
You really, really need to do this if you want to work on your own car..
https://www.alldatadiy.com/
Cause there's tons of info in there..
C4's are horribly confusing. They have all the tech new at the time, and none of the advance diagnostics that came later.
You really, really need to do this if you want to work on your own car..
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1993C4LT1 (05-20-2018)
05-20-2018, 04:29 PM
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05-20-2018, 04:31 PM
#12
Melting Slicks
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Sounds like timing.. Again, these things have all the tech that was new then, and none of the diagnostics.
I see one of your codes is the EST circuit. It's a single wire plug near the distributor that is disconnected to set the static timing. Then you plug it back in and the computer takes it from there.
You might check and see if it is plugged in. Also, if it looks corroded or varnished. and may be making a bad connection.
You can clean it if so. Put some oxygard on it or something similar.
I see one of your codes is the EST circuit. It's a single wire plug near the distributor that is disconnected to set the static timing. Then you plug it back in and the computer takes it from there.
You might check and see if it is plugged in. Also, if it looks corroded or varnished. and may be making a bad connection.
You can clean it if so. Put some oxygard on it or something similar.
Last edited by confab; 05-20-2018 at 04:34 PM.
05-20-2018, 04:37 PM
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Sounds like timing.. Again, these things have all the tech that was new then, and none of the diagnostics.
I see one of your codes is the EST circuit. It's a single wire plug near the distributor that is disconnected to set the static timing. Then you plug it back in and the computer takes it from there.
You might check and see if it is plugged in. Also, if it looks corroded or varnished. and may be making a bad connection.
You can clean it if so. Put some oxygard on it or something similar.
I see one of your codes is the EST circuit. It's a single wire plug near the distributor that is disconnected to set the static timing. Then you plug it back in and the computer takes it from there.
You might check and see if it is plugged in. Also, if it looks corroded or varnished. and may be making a bad connection.
You can clean it if so. Put some oxygard on it or something similar.
I'll take a look at that right away. Just kinda confusing.
05-20-2018, 04:38 PM
#15
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STOP!!
I know a guy who lost his 84 like that.. It burned to the ground. Same reason - backfire and then caught fire.
(Almost did it inside my friend's garage, actually.)
Fix that timing circuit and try a MAP sensor on it before you continue.
I know a guy who lost his 84 like that.. It burned to the ground. Same reason - backfire and then caught fire.
(Almost did it inside my friend's garage, actually.)
Fix that timing circuit and try a MAP sensor on it before you continue.
Last edited by confab; 05-20-2018 at 04:40 PM.
05-20-2018, 04:43 PM
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05-20-2018, 08:02 PM
#20
Racer
I have an '84 as well. I would invest in a Factory Service Manual as mentioned above. I purchased a CD version on eBay. This one is searchable. It should also include the Electrical troubleshooting supplement.
https://www.ebay.com/itm/1984-Chevro...EAAOSwzgRWu9FH
https://www.ebay.com/itm/1984-Chevro...EAAOSwzgRWu9FH