I have a 72 Cutlass Supreme, I'm trying to get started for the first time since I purchased it. The valve covers, driverside exhaust manifold, air conditioner bracket and alternator brackets are not mounted. The car turns over when I try to start it, but won't start. It was backfiring until I tirned the distributor, but still won't start. So my question is do I need to mount all the parts that are not mounted for compression, or is it something else?

 

If the previous owner took everything apart, you need to make sure the plug wires are installed correctly. The firing order is the same as a Chebby, but the plug wires go on the distributor cap in a counter-clockwise order. As long as you have a fully charged battery you should be able to start and run the engine without the accessories but you probably shouldn't run it very long without the exhaust manifold bolted up. It would be VERY loud! If you do run it without the accessories bolted up, take all the belts off so you don't damage anything and don't run it more than 5 minutes because the water pump won't be turning without the belts.

Any idea why it was taken apart to begin with? That could be a clue to what is wrong with it now.

 

put new points in it and check gas filter may be plugged with crap

 

You can spray some starting fluid into the carb before trying to start the engine. This removes fuel delivery issues from the mix of things that could be preventing the engine from starting. Don't spray much, a little goes a long way.

 

Check the basics. Is the rotor pointed to #1 wire when the engine is at #1 TDC? Are the wires installed in the correct firing order? Is the point gap set correctly if applicable? Is there power to the coil + terminal both in the key start and run position? Do you have good spark? While looking down into the carb, operate the throttle and see if there are 2 solid streams of fuel spraying down the throat.

 

Thanks guys, I am getting gas in the carburetor, all plugs and distributor are firing. I think the issue is with the position and timing

 

That's pretty basic then
surely you can verify #1 at tdc COMPRESSION stroke, and put the wires on in the correct CCW non-Ch*vy manner.

That should be sufficient.

 

Valve covers and the drivers exhaust manifold would be good to put on. Otherwise expect a mess, defening noise and probably sparks jumping around.

 

x 2.
Running engine with no valve covers = big mess quickly.

 

One thing to remember with Oldsmobiles is COUNTERCLOCKWISE!! Took me a while and several power valves to realize this.