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Vacuum at Idle

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bdcvg

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What kind of vacuum at idle for a stock BJ8 should be normal? I am used to 15-16" with a V-8 and medium performance cam. I can't get above 10 in the BJ8.
 
Thanks but I am looking for a vacuum reading at idle. I may have a vacuum leak somewhere causing My low vacuum so looking for a base line #. Probably the 14-20 range is where it should be but looking for verification.
 
Update. With freshly rebuilt carbs from Joe Curto and 20 mins of idle mixture adjusting with a vacuum gauge attached to the intake manifold, I ended up with 13-14" at 700 rpm. This seems to be normal for a BJ8 cam. The idle is ridiculously smooth. If I drop it to 500 rpm the alternator light starts to just glow a bit and it really sounds happy at 650-700.
 
bdcvg said:
Update. With freshly rebuilt carbs from Joe Curto and 20 mins of idle mixture adjusting with a vacuum gauge attached to the intake manifold, I ended up with 13-14" at 700 rpm. This seems to be normal for a BJ8 cam. The idle is ridiculously smooth. If I drop it to 500 rpm the alternator light starts to just glow a bit and it really sounds happy at 650-700.
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Can you show photos of how you hooked up the vacuum gauge, etc?
 
20220524_124512.jpg
 
So this is probably the feed for the power brake booster. I got rid of the wretched power brakes so long ago I forget. The tube goes to a Smiths vacuum gauge in My dash. The smaller threaded fitting would probably work.
 
bdcvg said:
So this is probably the feed for the power brake booster. I got rid of the wretched power brakes so long ago I forget. The tube goes to a Smiths vacuum gauge in My dash. The smaller threaded fitting would probably work.
Click to expand...
Thanks for posting photo I agree with you that the smaller threaded fitting would also work too.
I have often wondered if a small vacuum leak in the Servo could be a reason for the BJ8’s idle issues so many people have?
 
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