Emissions and drivability
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Joined: Jul 2001
Posts: 220
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From: milwaukee, WI
Emissions and drivability
i have a stock LG4, with a horrible bog and stumble. i failed on HC and CO the CO was at 94(standard 30) and HC at 3.8(standard 2) or something like that. i was told that my cat is probably clogged because of how rich it is running and when i changed my plugs, they were all wet. i just bought the car recently, but it passed fine in '99, i have the sheet, and the carb was replaced 3 years ago, i have the reciept. i can smell raw gas when i put my foot into it any more than half way. could it be my mixture control solenoid, over-active EGR, secondaries not openning? these are all ideas that i've been told. i neeeed help. i've gotta pass by 9-22.
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'84 Berlinetta, LG4, 700R-4, starwars interior, no major mods yet
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'84 Berlinetta, LG4, 700R-4, starwars interior, no major mods yet
Joined: Mar 2000
Posts: 43,187
Likes: 43
From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Nothing to do with the secondaries (unless something is seriously wrong, like rods missing).
1st check to make sure all of the connectors to the carb, distributor, and O2 sensor are connected. If so, then likely canditates are stuck or damaged float needle, bad O2 sensor, bad TPS. MCS is also a possibility, but I would think less likely.
Does the carb click when you turn the key to on? (You don't have to start it for this check). It should click for about 20-30 seconds, then stop. If no click, MCS.
If a piece of debris is keeping the float needle valve open, a quick way to clear that is to disconnect the fuel line to the carb and plug it, start the engine and let it run until it dies, reconnect the fuel line and start it again. This will drop the float, releasing the force on the piece of debris, and the in-rush when you reconnect the line will flush it out of the way.
Let us know what you find.
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82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R4. 2.93 limited slip. 2-1/2" cat-back, ZZ3 intake, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LG4 CC system w/'87 LB9 block, ZZ3 cam, ported World 305 heads, Hooker 2055 headers, 3" Catco cat & 3" catback, restalled TC, Spohn SFCs).
57 Bel Air, my 1st car. '66 396, 9.7 CR forged TRWs, Weiand Action+, Holley 750VS w/4150 conversion, GK 270 cam, Magnum rockers, Jacobs Omnipack, 1-3/4" Hedders & 3" Warlocks, TH400 w/TCI Sat Night Special conv & Trans-Scat shift kit, MegaShifter, 3.08 8.2" 10-bolt w/Powertrax, AMSOIL syn lubes bumper-to-bumper. Idles smooth @ 600 RPM in D. Best 15.02/95.06 @ 5800' Bandimere (corrected 13.93/102.4 @ sea level).
1st check to make sure all of the connectors to the carb, distributor, and O2 sensor are connected. If so, then likely canditates are stuck or damaged float needle, bad O2 sensor, bad TPS. MCS is also a possibility, but I would think less likely.
Does the carb click when you turn the key to on? (You don't have to start it for this check). It should click for about 20-30 seconds, then stop. If no click, MCS.
If a piece of debris is keeping the float needle valve open, a quick way to clear that is to disconnect the fuel line to the carb and plug it, start the engine and let it run until it dies, reconnect the fuel line and start it again. This will drop the float, releasing the force on the piece of debris, and the in-rush when you reconnect the line will flush it out of the way.
Let us know what you find.
------------------
82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R4. 2.93 limited slip. 2-1/2" cat-back, ZZ3 intake, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LG4 CC system w/'87 LB9 block, ZZ3 cam, ported World 305 heads, Hooker 2055 headers, 3" Catco cat & 3" catback, restalled TC, Spohn SFCs).
57 Bel Air, my 1st car. '66 396, 9.7 CR forged TRWs, Weiand Action+, Holley 750VS w/4150 conversion, GK 270 cam, Magnum rockers, Jacobs Omnipack, 1-3/4" Hedders & 3" Warlocks, TH400 w/TCI Sat Night Special conv & Trans-Scat shift kit, MegaShifter, 3.08 8.2" 10-bolt w/Powertrax, AMSOIL syn lubes bumper-to-bumper. Idles smooth @ 600 RPM in D. Best 15.02/95.06 @ 5800' Bandimere (corrected 13.93/102.4 @ sea level).
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