New owner of '77 280z from Upstate SC

[the_tool_man]

The ballast resistor is hooked up. Last night I read that the coil primary leads could be swapped. I'll have to check that too.

[the_tool_man]

15 hours ago, S30Driver said:

Without fail, request only NGK plugs from the parts store, the copper ones, nothing fancy like platinum.

 

Why not platinum?  I picked up my stuff today, and that's all they (O'reilly) had.

[S30Driver]

19 hours ago, the_tool_man said:

 

 

56 minutes ago, the_tool_man said:

Why not platinum?  I picked up my stuff today, and that's all they (O'reilly) had.

The old cars like the older plugs best, that is what they were designed & engineered for.   Platinum is mostly marketing hype.

Oreily's can usually order then & have them in 3 or 4 hours.

[the_tool_man]

New coil, plugs and wires. Still misfiring. I'm at a loss.

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[siteunseen]

What about a new cap and button?

I sold a D21 pickup for cheap. And all it was was the wore out cap was jumping fire. $10 cost me a fine running truck, damn it, still hurts.

[the_tool_man]

On ‎1‎/‎28‎/‎2017 at 5:09 PM, siteunseen said:

What about a new cap and button?

Yes.  I'll replace those.  I'll also check the ballast resistor (shoulda checked it while I had the coil out).  Last resort, I'll test the ignition module.  But I don't think that would be intermittent.

While I have the cap and button out of the way, I suppose I should check the air gap in the distributor.  Any idea what the side play of the distributor shaft should be?  I didn't see it in the FSM or the Haynes manual I have.

What if the PO hooked the coil primary up backwards?  When I changed out the coil, I hooked it up the same way the old one was.  The FSM doesn't show the polarity of the primary relative to the wire colors.  So I couldn't verify it easily.

Another possibility.  It could be that my 30 year old, cheap, inductive timing light is malfunctioning, and I'm chasing a problem that doesn't exist.  But it sure "feels like" a misfire.  And the timing light definitely shows the spark timing being quite irregular.

Edited January 31, 2017 by the_tool_man

[siteunseen]

I set mine even all the way around but can't remember the size of the gap.  Here's what I read, http://atlanticz.ca/zclub/techtips/distributorrebuild/index.html 

 

[the_tool_man]

Air gap was bigger than spec. Adjusted to 0.012. Spark is consistent at all speeds. Adjusted timing to 10 degrees BTDC. Still won't run smoothly. Now the engine backfires when I rev it off idle. It'll idle roughly when cold. But once it starts to warm up it won't idle for more than about 15 seconds before sputtering to a stop.

I think I'll start a new thread. This one's a year old. And almost no one is reading it any more.

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[Dave WM]

thead is getting long, did you get a reading on the new plugs?

[the_tool_man]

thead is getting long, did you get a reading on the new plugs?

Not yet. They've probably got about ten minutes of running on them since I installed them.

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[Dave WM]

12 minutes ago, the_tool_man said:

Not yet. They've probably got about ten minutes of running on them since I installed them.

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Well  suggest you pull them now and get some pics. this will help with diagnosing. I always start with new plugs and then run a short time then read.

[Dave WM]

If they are wet fuel fouled already, confrim CSV operation per manual

if that checks confrim TPS.

of couse confrim the Fuel pressure.

Temp sensor check at ECU for resistance at coolant temps

if still not right, try manually moving the AFM vane (cover off) to see if you can get the idle to work right.

 

all of the above assumes too rich a fuel mix. I had an intermittent mix issue that resolved when I swapped the EFI, then swapped back and it was fine again. So unplug the EFI and plug in again (if you dont have a spare to try).

You may have done all this already, as the thread is getting long.