Vette Registry | #8 cylinder not firing at idle - Page 3 - Forums

Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas

That's a possibility, but why only #8 cyl not firing? There are three other cyls on air/fuel supply side of the manifold. Weird, eh?

Joel Adams
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#8 cylinder not firing at idle

Posted: 9/20/06 11:29amMessage 24 of 30

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windrider1200

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Clifton, NJ - USA

Joined: 10/3/2003

Posts: 142

Vette(s): 1972 Coupe Ontario Orange Black leather interior LS-5; Turbo 400

Isn't there a vac port screwed into the manifold in the #8 runner?

Could be that what ever is attached to that port has a leak, forcing #8 to run lean.

On my 72 BBC, the Power Brake booster diaphram developed a leak, and I think it was # 8 that was running leaner then the rest of the pugs, after a visual comparison.

Just a thought.

BB NJ Ken

1972 T Top 454; "Boomer" Latest "upgrades": 1 1/8" front Stabilizer bar. Rebuilt SS calipers with O-ring pistons. Under car Chambered exhaust. Fiberglass rear spring (360lbs/in). Bilstein Rear Shocks. 3/4" Rear Stabilizer Bar. Tow hitch. Performer manifold with 600 cfm Holley. Comp Cam 262 .499 lift. L-88 Hood in process

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#8 cylinder not firing at idle

Posted: 10/5/06 6:21amMessage 25 of 30

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windrider1200

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Clifton, NJ - USA

Joined: 10/3/2003

Posts: 142

Vette(s): 1972 Coupe Ontario Orange Black leather interior LS-5; Turbo 400

Bill;

Any news on the cause of the mis-fire, or did I miss a new thread?

BB NJ Ken

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#8 cylinder not firing at idle

Posted: 10/6/06 1:45pmMessage 26 of 30

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jbox1

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i had my 68 that i just bought in the shop last week, and they said 4 of mine weren't firing. they adjusted the valves, and got them all to fire. same as yours, they would fire at higher rpm's, just not at low rpm.

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#8 cylinder not firing at idle

Posted: 10/10/06 6:59amMessage 27 of 30

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Bill427

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Hagerstown, MD - USA

Joined: 8/12/2006

Posts: 17

Vette(s): 1968 427 vert, BB. Auto, PW, PS, and PB.

Here is the update. I got a new carb built by BIGS performance, holley 780 CFM vacuum secondary's, it runs great. I guess the idle circuit must of been plugged up. Thanks for the posts.

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#8 cylinder not firing at idle

Posted: 10/10/06 5:27pmMessage 28 of 30

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Adams' Apple

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Duncanville, TX - USA

Joined: 11/8/2003

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That's kewl!!! Glad ya got it running right.

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#8 cylinder not firing at idle

Posted: 10/10/06 5:29pmMessage 29 of 30

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kstyer

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CUYAHOGA FALLS, OH - USA

Joined: 12/2/2003

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Vette(s): 1975 C3 Red, T-Tops, Black Interior. All I need is time and money! Getting there!

Good news. But if it was all carb, then at least 3 other cylinders, while perhaps firing, had to be weak. It must be a big improvement. Glad to hear it.

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