timing question
 

I've got a question regarding the timing in my k5.
First it is a 1975 cadillac 500 engine. I can't find specs on it. Alldata doesn't go back that old. I am having a problem with the truck "dieseling" when I shut it off sometimes. It is also a bitch to start sometimes. I'm gonna start with the timing and go from there.
Thanks to anybody that can help

Kewl.. old school!
Assuming the engine is basically stock mechanical config, no radical cam or real high compression.

also stripped of emissions vacuum stuff.

Now you didnt describe just HOW it manifests 'hard to start' I'm going to assume the common mistakes I used to see. And engine is harder to start warm than it is cold. Like it starts to turn over and like hits a wall.

If so, this is how I would do it:
First, Set points dwell angle to 30 deg. If you dont have dwell meter {go figger!} set gap to .016
set the idle to 600 rpm at warmed up. Adjust idle jets in till rpm decreases, then back out 1/4 turn.

Disconnect and plug vacuum advance line{s}. Note : It is VERY important to not have any vacuum leaks when you set the engine up! In fact it doesnt hurt to plug all vacuum ports on the intake, Incl brake booster and trans modulator. If RPM increases when you reattach them, then you have a problem to fix.

Check timing, Should be 8-10 deg BTC. That an IIRC.
I wouldnt be surprised if it were higher than that.

Also the timing mark should be steady and not 'dance around'. If it does, either your timing chain is sloppy or the distributor is worn out or both.

Attach vac advance line {manifold vac to end port}, IIRC the timing will go to 20 deg. Reset idle speed if necessary, then disconnect again and check timing again.

Here's the official document for cad..
http://www.teufert.net/caddy/caddy.pdf
Note there was an anti-dieseling solenoid {drops idle when engine shut off}
ymmv.

That would be right if it were for a 75. I don't have points. I appreciate it tho.

So gee, wonder where I got that idea?
Geeez! So you have an HEI. Or an aftermarket. So what! You dont have to worry about dwell.

The deal with setting the carb was a bonus, to make sure you were setting timing at the proper base rpm. It all works together.. Set BASE TIMING at 8-10 at 600 rpm, thermostat open.

:icon_angel:

You know if you want info on something it's sorta good if you describe the whole deal