My 85 T/A 350 sbc isn't turning off. Will shut off for split second but the putts over and dies down again. I ended up having to choke the carb to get it off. Possible timing? Or horrible vaccuum leak? suggestions and help?

 

What carb do you have? Is the 350 stock (understanding no 85's came with 350's from the factory), or modified?

 

Is it dieseling? running rough, banging and what not? or is it just like you flipped the key back on, nice and smooth?

Dieseling, run on without power to the ignition is generally caused by something creating a hot spot and/or airflow not being restricted enough.

If its running smooth then its almost certainly getting spark and your problem is electrical.

 

It's deffinately dieseling. I turn the key to the "Off" position and it dies down then putts back into a little rumble then dies down again then repeats. Yes it's basically stock and has a quadrajet carb. I've read up on those carbs and it tend to happen much often with them. So, I'm thinking get a new carb and it should fix the issue?

 

Don't get rid of the qjet, That's unnecessary. Where do you have your timing set at?

 

Not too sure just recently purchased the car 3 months ago and haven't had much time to mess with it. All I'd have to do is look at the distributor to see the degrees offset, correct?

 

You need a timing light to check the timing. The flat 4-wire connector that goes to the base of the distributor to the harness on the firewall needs to be disconnected while you check the timing.

Most likely putting the basic adjustments to the factory specs will solve the problem (timing, TPS, IAB, choke, idle speed, etc.).

 

Approx. how much will the Timing light run me? and how hard is it to set timing?

 

See https://www.thirdgen.org/settingtiming

You can get an el-cheapo timing light for 20 bucks at Harbor Freight.
Cadillac models cost more.

There are about a million youtube videos on setting motor timing.

 

Sweet man! Thanks

 

FirebirdJim94...here is a great video that gives you quite a bit of information. Just disregard the MSD ignition specific talk but the steps and information is the same.