1986 Chevy Celebrity 1986 celebrity computer is dead--how t

OOBERGOOBER

MEMBER
1986 CHEVROLET CELEBRITY
6 CYL
FWD
AUTOMATIC
102,000 MILES

Inherited my Grandmother's 86 celebrity w/2.8L V6 with 2 bbl carb. It ran fine for a day, but then refused to start. Cranks all day, but no spark. I have voltage at the coil, and it's getting fuel. Checked the computer, and all it would do is endlessly flash the initial "12" code. Rented an obd1 tool, and it kept saying no codes--check connections. Gotta think the computer is dead.

First, how do I remove the computer? I have the lower dash valence off, and can't seem to locate it.

Second, I assume this computer has a prom, not an Eprom like later models--true? Where will I get another prom if the dealership can't get one?

Thanks.

9 Replies

JDL

MECHANIC
16,098 POSTS

I'd start by checking primary voltage at the coil. That feed usually goes hot when you turn on the key, pink wire. The primary wires are smaller wires, the secondary wires are thicker wires, secondary voltage will bite.

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Friday, October 29th, 2010 AT 11:14 AM

OOBERGOOBER

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It's not the ignition system; it's the computer. I need to know how to access & remove the computer.

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Friday, October 29th, 2010 AT 11:30 AM

JDL

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Engine cranking, the computer has nothing to do with spark at the plugs. Have a good day.

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Friday, October 29th, 2010 AT 12:36 PM

OOBERGOOBER

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I have 12v at the coil terminal with key on. The plug wire from the coil to the cap is good. Replaced plugs, ignition cap, rotor, and ignition module.

She was running fine one minute, and I changed out the air fliter, and she's never started since. Thought I'd knocked something loose, but can't find anything disconnected.

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Friday, October 29th, 2010 AT 12:40 PM

JDL

MECHANIC
16,098 POSTS

The negative side of coil should have a pulse with engine cranking, If no pulse, check the pickup coil. The ignition module has to have a signal from the pickup coil. Did you visually check for spark at the plugs, engine cranking? I don't know whether or not you have an esc module on this? Are you fuel injected or feedback carb?

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Friday, October 29th, 2010 AT 1:28 PM

OOBERGOOBER

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I live alone, so can't turn the key & check for spark myself. I'd just changed the plugs, and she purred like a kitten. Then I changed the air filter, and no spark since. Sprayed starter fluid in the cylinder, still nuttin.

She has the 2 bbl carb. Where is the pickup coil located, and what does it look like?

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Friday, October 29th, 2010 AT 1:56 PM

OOBERGOOBER

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Okay, figured out what the pickup coil was. It's covered with a light orange corrosion.S that a problem? There's a green and a yellow wire coming off of it. I should have continuity across them, shouldn't I?

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Wednesday, November 3rd, 2010 AT 7:12 PM

RODOLFO MARTINEZ

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1 POST

Good morning from México, something similar had, between the carburetor and distributor there are the electrical connectors in of distributor please verify there was no loosen or changed and enjoy your ride.

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Sunday, February 23rd, 2020 AT 8:51 AM

KASEKENNY

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18,907 POSTS

Great information. Thanks for helping to add to this site. The original post was 10 years ago so it may not have helped this person but I am sure that will help others.

Please come back if you need any assistance. Thanks

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Sunday, February 23rd, 2020 AT 4:09 PM