i have a 93 fd with a pettit racing street port motor and my vacume is at about 10. the car idles low and wont take any idle adjustment. i have the bleeder all the way open and the idle is still low. like 600 rpms i would say. even when i gas it up to like 1000 rpms the vacume still remains low. could this be a cracked or chipped seal? the motor idles perfectly smooth with no bounceing of the vacume needle. and i checked the whole motor for vacume leaks. has anybody herd of a motor running real smooth with a steady vacume reading but really low?

 

It may be that your motor is just old and tired. That would yield low vacuum numbers. The sure fire way is to do a compression test to see how strong it is.

 

^^ Good point. If the reading is steady (instead of bouncing), your motor may be tired.

Low vacuum and a smooth running motor do not mix Make sure your boost gauge is working (and that you know how to read it; you didn't even say what the units were... you mean 10inHg, 10mmHg, 10psi,???) properly. You may even want to just hook up an external gauge directly to the UIM nipple with the hood open to rule out if the gauge is faulty (or if you have a bad vacuum connection to the gauge). Good luck.