280z 280z 78 Wont idle, Running Rich, out of ideas.

[Dave WM]

8 hours ago, Cyrillink said:

While it was set at zero (FACTORY Mark) on the distributor, on the timing was a little below 20 once i moved it all the way up i was able to get it to position 5. Car ran much better sound wise, BUT! i started getting black smoke! not much though.  probably F/A ratio idle screw needs adjusted changed. 

Thinking about moving a tooth down on a cam to fix timing

I am a little lost on this. You need to make sure the dist drive slot is set at 11:30 (see FSM for a better explanation) when you are at TDC compression stroke piston #1.  You may want to confirm the timing mark on the harmonic damper to the actual TDC just to make sure its correct. I set my single coil setup at 10 degrees advance at idle (no vacuum from ported vacuum). If everything is setup right you should be right about in the middle of the range of adjustment on the distributer when done.

On the cam timing, generally you check a slot and a v cut on the top cam chain sprocket, however from looking at your sprocket is may not have the V notch cut in it to allow for a visual inspection. I am mentioning this since you spoke about moving a tooth down to fix timing.

[jonbill]

Just checking : you know cam timing is completely independent of ignition timing, right? It's just you mentioned adjusting cam timing after talking about ignition timing problems.

[Cyrillink]

2 hours ago, Dave WM said:

I am a little lost on this. You need to make sure the dist drive slot is set at 11:30 (see FSM for a better explanation) when you are at TDC compression stroke piston #1.  You may want to confirm the timing mark on the harmonic damper to the actual TDC just to make sure its correct. I set my single coil setup at 10 degrees advance at idle (no vacuum from ported vacuum). If everything is setup right you should be right about in the middle of the range of adjustment on the distributer when done.

On the cam timing, generally you check a slot and a v cut on the top cam chain sprocket, however from looking at your sprocket is may not have the V notch cut in it to allow for a visual inspection. I am mentioning this since you spoke about moving a tooth down to fix timing.

Hey Dave,

When i checked my U cut out straight on the mark.   Below is an example of kinda what i see. except the U shape is right below the mark. 

 

[Dave WM]

if the U matches the mark then you are fine on the cam timing. get a pic of the dist drive (distr off look down to see the drive tang) with the crank set at TDC.

[siteunseen]

That line should look like your example pic above. If it's even with the U cut out, its retarded. Moving the cam sprocket to the next number will fix that.

 

Edited January 6, 2020 by siteunseen

[Dave WM]

another thing to keep in mind when you are checking that notch, make sure you have the timing chain tight side tight (the tight side is the distributer side). That is you must not reverse the crankshaft if you overshoot TDC, if you do you will have slack on the chain where you don't want it for reading the marks.

[siteunseen]

Maybe wrong on retard vs advance?

[Zed Head]

I think that the mark is actually in between new and worn out enough to move.  It's normal wear.  If he move's it it will be too far advanced.  It's on #1.

[Zed Head]

18 hours ago, Cyrillink said:

Checked the Timing with a timing gun and found interesting stuff;

While it was set at zero (FACTORY Mark) on the distributor, on the timing was a little below 20 once i moved it all the way up i was able to get it to position 5. Car ran much better sound wise, BUT! i started getting black smoke! not much though.  probably F/A ratio idle screw needs adjusted changed. 

Thinking about moving a tooth down on a cam to fix timing.

Does "position 5" mean 5 degrees advanced?  Not sure what you're looking at or doing.  Timing should be set at about 10 - 15 degrees advanced, normally.

[Zed Head]

18 hours ago, Cyrillink said:

Side Note Question: 

Any recommendations on a new coil to run with out the ballast resistor. Currently have ACCEL 8140C superstock 1.4 ohms on the primary. 

Your coil should be matched to the ignition module, or points.  What are you using?

[Cyrillink]

On 1/6/2020 at 6:22 PM, Zed Head said:

I think that the mark is actually in between new and worn out enough to move.  It's normal wear.  If he move's it it will be too far advanced.  It's on #1.

 

On 1/6/2020 at 2:28 PM, siteunseen said:

Maybe wrong on retard vs advance?

 

On 1/6/2020 at 10:39 AM, jonbill said:

Just checking : you know cam timing is completely independent of ignition timing, right? It's just you mentioned adjusting cam timing after talking about ignition timing problems.

 

Hey Team,

Moved it to timing mark #2 on the cam, everything checks out right. Tightened all screws car cranks and put everything back together. Timing light is firing about 15 degrees of TDC on crank. Car wont start (facepalm). Distributor is set to factory marking. not sure what da hell is going on.

[siteunseen]

I would loosen the distributor and have someone crank it over while you turn the distributor. It should get better one way and worse the other.

You say it cranked but now it won't. Check the simple stuff. Coil wire, rotor button, etc.