Rochester 2GV idle settings on 71 140.

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Rochester 2GV idle settings on 71 140.

Postby 71GTKammback » Tue Apr 10, 2007 8:16 pm

I have most every manual put out by GM and others on the Vega from 1971 and beyond. I am wondering if there is not a misprint on one piece of data. What do you all think? And the manuals mimic the underhood sticker on my car. A 1971 Vega L11 2bbl.

Low idle for Manual transmissions both 2bbl and 1 bbl engines is 700RPM. This is set by the idle screw on the carb.

Curb idle for Standard engine manual transmission = 850RPM
Curb idle for 2bbl engine manual transmission = 1,200.

The curb idle is set by the carburetor solenoid. Presumably the solenoid sets the running idle and then when you shut off the engine the solenoid de-energizes and retracts letting the idle back down to the low idle setting so it will not deisel.

Problem is.... why would the std engine curb idle be set at 850 rpm and the 2bbl curb idle be set at 1,200 rpm. 1,200 rpm seems way too high to be running any car's idle speed. I have never seen a stock carb setting much above 850.

All other carb settings for manual transmission Vegas through all years is 700-850 except for 71-72 2bbl Rochester manual transmission cars.

I know I can set my car at anything I like but I am just trying to get to the bottom of a slight stumble on acceleration and I wonder if GM did not do away with the stumble by increasing the curb idle speed.

Thanks for any help!

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Postby bill1978v8 » Fri Apr 27, 2007 10:10 pm

I would follow the manual as they all say the same thing. 1200/700 for a manual trans. The 1977 Starfire with a 140 or 2.3 Litre is 1250/700 with a note. High altitude is 1250/800. You can set it how ever you like depending on altitude etc. How does it run? does it diesel? Is the off idle stumble the only problem. Is this a Rochestor 2GV?

1975 Monza 2+2, 4.3L V8, Auto
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