I've recently noticed the idle on my Olds equipped LeSabre is racing when in park, since the car has no tach it's hard to say what it's going up to but it's clearly louder than one would expect at idle. I'm not even sure what carb GM put on these cars from the factory. I know it's a Rochester(?) but what model? What are some things I should look at to see why it's racing. I don't know if trying to adjust the idle on the carb would solve anything since it's probably some type of vacuum source causing the issue?

I've also started to look at EFI systems to get rid of all the emissions and vacuum lines GM decided to add to these cars. If I was to go with a Holley Sniper EFI, which style carb mount would I need?

 

Look on the right side of the carb for a sticking high idle cam, check for vacuum leaks, check for stored trouble codes. Does the choke open completely when the engine is warm?

 

You will need an adapter or the Quadrajet Sniper. The Sniper 2 with an adapter may be the best bet. The bolt on EFI have issues as well, some no issues, otherwise many. A custom tuned non computer Qjet and regular HEI distributor, most cheap ones are decent now, is also an option.

 

Nothing at all wrong with all of the emissions parts as long as you take care of them. My Wife's 84 Riviera is well over 300K miles and runs just fine with all of the emissions parts. I did replace all of the vacuum lines when I had the engine out a few years ago but otherwise it is all stock.