Distributor/Oil Pump Shaft Timing

[Bigbrowndog]

Folks-

 

I have a 73 240Z that is having difficulty.  I have done a lot of reading on this one, and everything looks to be right in terms of the oil pump shaft per the pics I have seen and descriptions. At top dead center on number one it is at 11:25 or so.  The cam gear marks line up as well. But I cannot advance the distributor enough using the factory bracket on the distributor.There is not enough adjustment when I turn it counter clockwise to keep it in groove on the base bracket. I have loosened up the second bolt on the underside of the distributor and everything is at the end of adjustment to get it to run. The motor was just rebuilt by the previous owner.

 

Makes me wonder if the oil pump shaft should be moved to the next groove, or if there are different distributors and brackets for different years. Again, looking at the pics the oil pump shaft looks to be correctly installed.

 

Has anyone run into this before?  

 

The other issue with this is the coil gets hot, as does the baseplate under the points. The base plate will burn your finger when trying to start (really hot). Is there possibly a grounding issue or is an MSD coil just too hot for standard points. I have an HEI distributor that I am looking to install & may just put it in now but the timing issue has me wondering what is going on.  

 

Any help is appreciated.

 

Thx

[NewZed]

 

I have a 73 240Z that is having difficulty.  I have done a lot of reading on this one, and everything looks to be right in terms of the oil pump shaft per the pics I have seen and descriptions. the end of adjustment to get it to run. The motor was just rebuilt by the previous owner.

 

, or if there are different distributors and brackets for different years. Again, looking at the pics the oil pump shaft looks to be correctly installed.

 

Has anyone run into this before?  

 

The other issue with this is the coil gets hot, as does the baseplate under the points. The base plate will burn your finger when trying to start (really hot). Is there possibly a grounding issue 

Does it start and not run?  Or not start and not run?  Or not spark and not run?

 

There a different mounts for different distributors.  The wrong one will give the wrong range.  With points it's pretty easy to see when they are about to open.  That will be when the spark happens.  You can get a rough idea of timing by timing by looking at that.  Turn the distributor until the points are about to open and see where the timing mark is.

 

Sounds like your ignition circuit might be shorted.  "Trying to start" could mean standing there with the key on, or cranking the engine for extended periods of time.  You could measure voltage with the key on and compare it to key off.  If no current is flowing, they'll be the same.  If the circuit is shorted there will be a voltage drop.  Could be that your points just need adjustment.  Not opening.

[luseboy]

So you're unable to get it to start right? It's a little unclear from your original post.  If you can get it to start, see where the timing is at with a timing light.  Additionally, make sure you have the right firing order, and that the wires are in the right spot on the dizzy cap and verify by setting the motor to TDC and seeing which spot on the cap the rotor is pointing to.  If I remember correctly, this will go to cylinder #1, and then you want to set the firing order off of that.  Also, pull out your multimeter and start testing for voltage at the coil.  If it's not starting, verify that you're getting fuel and compression and that the carb is functioning reasonably, perhaps it's not starting due to another problem.  I know I had a really tough time getting my pump shaft timed right at first, as it can be a little tricky to decipher, I wish they would have put timing ticks or something on there.  I personally know pretty much nothing about points as I got my distributor with a pertronix already installed, and I've never had to deal with points, but I'm sure many members on here know all about them.  The "shotgun approach" to fixing things (replacing parts blindly) is generally frowned upon by the more experienced members here, but you might try the other distributor, if nothing else it will help you narrow down what the problem is.  Another thing to look at is the harmonic balancer, these are known to fail (especially after 40 years) which often starts out with the outer ring sitting at a different spot on the outside of the pulley than it once did.  This makes the timing mark no longer relevant.  It may be that your harmonic balancer has shifted and your "TDC" is not actually TDC.  You should be able to confirm this by pulling the valve cover and looking at the cam lobes while cylinder #1 is at TDC. I'm bad at explaining this kinda stuff but this has been discussed quite a bit, there are two cam lobes that stick up at actual TDC, so confirm that your engine is really at TDC when you're trying to time the distributor.  If none of that works you may want to go through the ignition wiring rabbit hole and make sure it's all hooked up right and getting voltage and not shorting.  Beyond that I can't think of anything rational that would cause it not to start, unless the plugs are corroded to the point of having no more gap but I assume they got replaced after the rebuild.