Unhooking emissions pump

[CadillacFlashback]

My emissions pump on my '71 CDV has a visible wobble in the pulley, and I'm wondering if that is a factor in the vibration I have been chasing. Is there a problem with removing that belt?  Will I need to adjust anything (timing, mixture, etc) if I do?  Not really familiar with exactly what that contraptions does.

Thanks

[Scot Minesinger]

That smog pump is worthless and I would remove it.  Call MTS in CA and they sell a kit for that, which I installed on a 1972 Cadillac, works perfect.  Problem is the smog pump serves as an idler pulley for water pump, so that needs to change to the alternator serving as idler pulley, just like a 1970 Cadillac.  From 1968 thru 1974, 1970 was the only no smog pump year plus it did not have fan clutch, so quite a durable set up there in 1970.

Don't under estimate how much vibration and rough idle a bent wobble pulley causes.  I replaced a similar bent one on a power steering pump for a customer, because they wanted a nice engine compartment and it was not bent that bad.  Afterward it was quite a transformation.  To prove this today you can temporarily remove the belt when engine is cold (no water pump) and run it for a minute and you will see how much nicer it is.

[bcroe]

If a belt has a very long span between pulleys, it might sometimes vibrate.  I have fixed
a couple of these by adding an idler pulley to break up the long span.  Bruce Roe

[walt chomosh #23510]

scott,
  I pull belts off (briefly) when troubleshooting motor vibrations. And,my experience also shows that too long of a span between pulleys call for a idler as bcroe suggested.(look closely at your motor mounts)...walt...tulsa,ok

[Scot Minesinger]

The belt for this revised set up is about a 50 inch diameter ID, and it is not too long.  I just completed this on a 72 Eldorado and she is super nice running, no vibrations.  Plus the a/c to power steering double belts are longer and will be the first to cause an issue with long span.  My 1970 Cadillacs do not vibrate either.  This long belt thing is not an issue on this application, else the 1970 Cadillacs would have a reputation for vibrations.

["Cadillac Kid" Greg Surfas 15364]

Gentlemen,
The discussion about long belts causing vibration does not seem to be applicable in this instance.  The Air pump to water pump belt on the AIR cars is 38 inches.  The crank pulley/water pump/alternator belt that was used in 1970 and essentially all cars without AIR is 51.5 inches.  The simplest solution to the issue is check the AIR pump pulley to see if in fact it is bent or if the problem is in the pump itself. Then straighten/correct the pulley and eliminate the need for all the modifications. 
Greg Surfas