Distributor question/issues

[ElCimino]

Ill start with some info about the car then my question. '73 240z L24, round top su carbs, 4speed transmission, headers, electronic ignition. Now to my question/problem. With a timing light connected to #1 cylinder wire and the car at idle the tab shows slightly below -7. I could be wrong on this but from what I've read the marks are from low to high -5, 0, 5, 10, and 15. Please correct me if I'm wrong on this but regardless the timing was showing below the lowest mark. This is only achieved by having the distributor turned as far advanced as possible. Any turn to retard the timing would cause the car to idle roughly and die. I found some pictures while searching that showed my plugs were in the right order but were one plug off to the left if you are looking at the distributor from the drivers side of the car. So I moved them forward one each and the retarded the timing to compensate for the change. The car would run with this change but only if I now turn the timing all the way to retard. The timing marks at this setting shows a little above the +15. When I advance the timing the car idles rough and the dies. I wouldn't really care if it ran fine but it sounds like it just needs a little more advance or retard in either configuration to run smoothly. From what I can tell the po installed a reman distributor (card one?) and added a pertronix electronic ignition module. The coil doesn't have a name it's just black. There is a ballast resistor. Everything functions it just doesn't seem right. Any info is welcome. I can take pictures this evening of anything you need.

Thanks,

Chris

[240260280z]

Set engine at top dead center then check to see if the timing mark is at "0" as a first step (bottom right corner of big photo below).

Then lift distributor and look a the end of the spindle that drives the distributor for the 11:30 angle with the smaller 1/2 facing forward. (first photo below)

Once your timing mark and distributor are verified (mechanical timing) then move to electrical timing (plug order and distributor rotation)

Edited July 12, 2013 by Blue

[Jarvo2]

Great pictures (as always), Blue. For the early 240's though with the marks on the pulley, I believe they start with 0 (zero) and go up in increments of 5 degrees....right?

[240260280z]

Here is a photo I found on this site. The bottom mark should be zero and align at TDC. Each additional mark is 5degrees BTDC

[240260280z]

Here is a 4cyl pulley's marks which looks like 240z

[ElCimino]

Thanks for the reply Blue. I will check that this evening. From memory I don't think my rotor is in the position that your second picture shows. Ill double check this. To check the timing chain ill need to pull the valve cover and get a new gasket?

I just saw your post with the timing marks so I'm either just below zero or above the +20 depending on the configuration of the spark plug wires connected to the distributor.

Thanks

Chris

Edited July 12, 2013 by ElCimino

[240260280z]

No need to pull the valve cover. We'll assume the chain is ok.

Just get the piston #1 at the front of the motor in it's highest point (remove plugs and turn crank with a 27mm socket by hand)

Once at Top Dead Center, confirm the timing mark is at 0 on the damper pulley and that the distributor driving spindle end is at 11:30

[ElCimino]

Ok I get off work at 9:00 pm Tulsa time. Expect a post late this evening or early tomorrow. Ill try to post some pictures of my findings. Thanks for your input I appreciate it greatly.

Chris

[ElCimino]

Here's what I have. All pics taken with #1 TDC. The key for the distributor looks like its running parallel to the engine. Not sure why all the pics are on their side.

Edited July 13, 2013 by ElCimino

[Mikes Z car]

I THINK pictures get turned sideways in the upload process from my own experience because they are taller than they are wide.

[240260280z]

Great photos. The crank-driven-spindle that connects the oil pump to the distributor is clearly retarded thus your -7 degrees.

You can correct this by dropping the oil pump and rotating the shaft. The pump has 4 bolts that hold it to the timing cover. sometimes the sway bar may be in the way so you may have to move it.

Another way is to manipulate the plate under the distributor by drilling new holes and oval-ing existing ones or by changing the bracket that holds the distributor.

I recommend just dropping the pump and spindle with the engine at TDC and follow the procedure that i will post in the next message as an attachment.

The bottom line is that your electrical timing is retarded so you need to advance your timing.

[240260280z]

Step 23 is all you need to do in the attachment. Make sure the motor is at top dead centre when installing and you are good to go.

Oil Pump.pdf