Engine Running Rich---2 barrel 327 1968 - Team Camaro Tech
Troubleshooting Diagnosing problems done here.

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post #1 of 3 (permalink) Old Apr 23rd, 03, 10:16 AM Thread Starter
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Hello All, My 68 327/210hp is running rich. Not bad enough to smoke black, but bad enough to burn your eyes out after a short time. This a Rochester 2 barrel (tag # 7028110). It seems worse at idle. I have been through the carb twice and know it is clean. Ignition timing is perfect and vacuum advance is operating fine. Float is fine and float level is right. I've disassembled the carb again and the only thing I can find is this: The "power piston" built into the carb top doesn't move when vacuum is applied to its port. Should it? According to all the books I've read, the power valve in the bottom of the float bowl is to be closed with vacuum applied to the "power piston" in the carb top. This thing is driving me crazy. [img]graemlins/clonk.gif[/img] Ok, all you 2 barrel experts, please help! Thanks!
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post #2 of 3 (permalink) Old Apr 24th, 03, 12:58 AM
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I'll try this one. The power valve "sinks" into the fuel bowl with engine running and full manifold vacuum applied. Open throttle, and until engine rpms catch up to throttle position, power piston will open, then as vacuum (rpm) catches up with throttle position, power piston sinks into bowl. I'm sure you've set the idle vent @.050" IAW ( in accordance with) overhaul instructions.

Use a vacuum gauge and perform the adjustments, idle mixture, base timing, and use dwell meter to set point gap and adjust for max vacuum reading. With stock cam, should have a steady 18-20 inches of vac.

Another place to check is the timing chain/sprocket slack using a flex handle and socket and the harmonic balancer markings and rock the crankshaft back and forth and count the degrees of slack against the pointer. Anything over 10*, replace timing set.

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post #3 of 3 (permalink) Old Apr 27th, 03, 02:02 AM Thread Starter
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Thanks for the tips.
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