greek cutlass

Hi all, so glad I found this site!
I have a 1971 Cutlass S with a 350 Rocket with a 4bbl rochester carb (I think carb is from a 73 - from looking at decoder on site). I have had car for about 10 years. The vacuum advance hose has never been connected to carb.
I am having issues and cant seem to figure out the cause. Symptoms are RPM flucuate when I let of gas pedal or while in drive but stopped (at a light)
Not sure if its the timing, vacuum advance or something else???
Anyone have a suggestions.

Also, I used to use Baddock for parts, they are out of business, anyone know of another catalog company for classic olds?

Thanks.

viper771

fusick.com is a good site to use for parts. There is always Brothers Automotive Parts (oldsparts.com) but I get bad stories about them (haven't tried them myself) but they offer quite a few parts. You can also find Tamraz parts on ebay and they have good stuff as well.

I can't help you with the RPM flucuate unfortunately. I am still a rookie in this hobby and learning myself. I am sure someone here has the answer for you

cutlassgal

Welcome to our site! Fusicks is great - a lot of us use them, lol! There's also Year One, check them out too!

oldcutlass

When was the last time your tune was checked??? Timing/ dwell, is the car running rich or lean, why was the vac advance disconnected? Any mods to the motor, trans??

Oldsguy

First, welcome to CO. You may have a vacuum leak if the hose is completely removed and the source has not been capped. You really should get a factory service manual which can give you the correct routing of all your vacuum hoses and all the vacuum switches required for your model/year/engine combo. After that is resolved, then you can give 'er a tune up and get riding. Good luck.

greek cutlass

thank you all for your replies & welcoming me to the site!
Viper & Cutlassgal Thanks for heads up on Fusicks, I will check them out.

Oldscutlass, engine is running rich. Previous owner did some mod work. Carb & manifold are from a 73 Supreme. Some trans work (rebuilt 2001) was done too. Other then that, its pretty stock. Ive had car since 2002 & vacuum advance hose has always been disconnected, its been capped off. Not sure why previous owner rigged it that way but it worked, so I kept it. I connected the hose to see if that would help regulate the flucuation, but it ran worse with the vacuum advance hooked up...go figure.
Last tuning check was a little over a year ago.
I had alt work done & some oil leaks repaired in the past two months.

Oldsguy, yeah a manual would be nice! I only have basic mechanical knowledge, but enough not to trust mechanic.

Just wish I could figure it out, I really think its timing or the vacuum advance. the choke sticks sometimes too. Whats the best way to DX the issue??

thanks again!

oldcutlass

OK start with the basics, points and condensor if you got em, new plugs, and wires if they have not been changed in a while! I would also change my air and fuel filter!!

Set your dwell to 30, if you have points, and your timing to 12-14 BTDC. Reconnect your vacuum advance to ported vacuum. Adjust your idle to around 700 - 750 rpm in gear. Adjust your idle fuel mixture screws on your carb for the highest rpm or highest vacuum which ever you prefer in park! Then reset your isle speed in gear.

With your timing light see if your getting advance when you increase your rpm. Then at idle switch your vacuum advance to manifold vacuum and ensure that your vacuum canister is working on the distributor. If you do not get an increase replace! Its 2 screws and $19.

Good luck!

greek cutlass

Took your advice you were spot on! THANKS Oldcutlass!
Went to mechanic and gave her a well needed tune up, all the basics, plugs, wires, points, caps, filters...etc. Hooked up vacuum advance, set timimg & dwell. Running MUCH better. HOWEVER, still running rich as we had to set timing a bit higher then required. MY rochester 4bbl carb needs work. We thought it was float issue due to mixture but its not. Seems to be idle circut issue.
So now need to figure out is it better to rebuild what I got, go for holly or edlebrock??

Thanks

oldcutlass

What is your idle set to??