My son and I got a 1970 914-4 to fix up and it doesn't run. Many things are not connected hose wise so we and yet don't even expect it to run of course at the moment, but want to see of engine has potential to run or needs a rebuild. First step was to see if engine was seized because we could not by hand turn the driver side real wheel when it was in the air and with the other 3 wheels on the ground and (5th gear ;spark plugs removed). So we added some oil to each spark plug hole, let sit overnight then rocked the car a bit and it broke through whatever was holding it up! Probably a little rust or something in a cylinder(s). Now engine turns smoothly. We removed the starter and tested it and both the solenoid and starter are good. So we put the starter back in an then cranked the engine with a brand new battery connected directly (bypassed ignition as there is no switch/key). The engine cranks but slowly like one revolution per 1.5 seconds. Connecting to battery of my running pathfinder did not improve the churn rate. The distributor turns accordingly as it should. Compression test in 2 different cylinders never got above 50 PSI. Is the low PSI because of the sluggish churn or because of a blown gasket or something? This is my first compression test but I think we did everything right. Spark plugs snugly in 3 holes and compression tester snugly in 4th hole and throttle wide open. I didn't change the oil upon purchase but the dipstick shows oil in there and there is the oil we added to the spark plug holes too. Should we try a leak down test instead of compression test and why is the churn so slow?

You do need to get a decent spin (turn not churn) to get a good psi reading. My guess is poor grounding as to why it is not spinning g faster.

And change the oil.

I would change it several times as you bring it back. All the rust and crap will be moving with that oil. Now Is not the time to do more damage. Water etc accumulates in sitting engines.

Sounds like a bad ground connection.

Also compression check you should remove all 4 plugs and then check comp on each cylinder.

Jim

Welcome aboard, and it looks like you guys have a project on your hands. I would bet it's a poor connection causing the slow cranking speed. If/when you get it cranking good you want all the plugs out and the throttle plate wide open. Best of luck and keep us posted as to your progress.

@Tking327

There should be a copper braided strap at the tailcone on the trans that gouunds to the body above. If it is missing or broken you can use a jumper cable to ground the trans.
And remove all spark plugs an open the throttle(s) all the way when doing a conpression test.

If you tested that starter under a load and it was OK, check your ground strap at the battery and the tail end of the trans to the body. Clean clean clean, positive side too.

If all of the above fails replace the starter or get it rebuilt
had the same issue with a rebuilt engine