260Z dizzy and coil trouble.

[MDZED]

Hi guys, new user, new owner. 

 

I have scoured forums, and have an original FSM.  Trying my best to search before reaching out, and doubly trying my best not to freak out and start replacing parts or tow to mechanic.

 

I have a 74 260Z.  Initially had some issues with starting and battery getting drained.  I replaced the alternator with a frontier alternator and bypassed the external regulator.  Things were looking great.  Weeks later, started to have some running issues, so I took it to mechanic. He installed a new coil, new point, and bypassed the ballast.  After getting the car back it was running fine for a few weeks, but started having some issues starting.

 

At some point the car was switched back to a single point dizzy, I bought a zcardepot electric dizzy and tried to swap it in.  The rotor was 180 degrees off, so went back to the original single point.  But when back on the old point dizzy, had significant running issues, would idle fine and run 2-10 minutes and just lose power.  Would not reliably restart, and would have to advance or retard the timing to get off the street.  In a likely dummy move, said to hell with it and went down the path of swapping to a pertronix electronic dizzy conversion and getting no results.  I think I am painting myself into a corner and want to move smartly back to normal operations.    

 

Problem 1: Swapped back to old points dizzy.  The car started and idled fine, I checked timing and it looked decent. But would loose power when driving.  In order to get off the street, would need to either retard or advance timing to get it started.  Moved the engine to close to TDC and adjusted from there.  Would again start and idle for a bit, but loose power.  Unless I have the engine at TDC, it wont start.  If at TDC it will start and run for a bit, but die and not turn over unless at TDC again.  Still have the ballast bypassed.  

 

Problem 2: Swapped the point to a Pertronix electric conversion.  Still Getting zero fire on that.  Tested spark to plug and nothing, test spark from coil to dizzy, nothing.  Checked if coil was getting power in the on position, ran a wire from neg side on coil and tapped valve cover and had spark.  The coil is 1.4ohm and running the ballast as bypassed still.  Even tried swapping dizzy wire around from + and -.

 

Fairly certain all wires are connected properly and nothing is hanging loose.

 

Not sure where I go from here, do I keep pursuing the pertronix route or go back to points?  If I go back to points, not sure why I am having new problems and where to look next, I am in self denial that another problem has arisen (ICM).  Any suggestions would be appreciated, the FSM is a bit short as I am now off the reservation.  

 

 

[bunkhouse]

 Are you sure it's getting fuel? Running for a few minutes and then losing power or dying could be fuel starvation.

[MDZED]

I should have mentioned that, yeah I am pretty sure she is getting fuel.  After she dies I can look into the carbs and see she is getting fuel when I pull the linkage.  

[NewZed]

On 6/17/2024 at 9:32 AM, MDZED said:

Problem 1: Swapped back to old points dizzy.  The car started and idled fine, I checked timing and it looked decent. But would loose power when driving.  In order to get off the street, would need to either retard or advance timing to get it started.  Moved the engine to close to TDC and adjusted from there.  Would again start and idle for a bit, but loose power.  Unless I have the engine at TDC, it wont start.  If at TDC it will start and run for a bit, but die and not turn over unless at TDC again.  Still have the ballast bypassed.  

 

Not really clear what you're saying here.  But it looks like the closest to success of the two.  What does "engine at TDC" mean?  Do you mean igntion timng set to zero advance?  As soon as you hit the starter the engine moves off of TDC.

 

You need to define what is reproducible.  You said that at some point it started and idled fine.  Then apparently it was drivable until you adjusted timing to get more power and it would not start anymore.  Also, apparently, you lost track of what the timing was becuase you ended up advancing and retarding it until it would start again.  Why not just set it back to where it was when it started and idled?

 

Way too much vaguness in your work.  If you find a setting for the distributor that allows the engine to start and idle, put a mark on the adjustment plate so that you can go back to that exact spot.  Years ago on my very first car I got stuck in a problem like yours where I tried to adjust timng like I always had and got it so messed up that I couldn't figure out which way to go.

 

Since you're running carbs and the original distributor was electronic (260Z) I'd guess that the replacement distributor has messed up mechanical advance and/or the vacuum advance is not connected or it is connected and the breaker plate is sticking.  You can check those with your timing light before you even try to drive the car.

 

On the Pertronix - they are sensitive to leaving the key on.  The key was probably left on and the module burned up.  They actually have a warning in the instructions about that.  Also, bypassing the ballast allows more current flow which will burn it up even faster.

 

No offense but there's lots of wrongness here.  I would try to get back to your first sentence (starts and idles fine), measure timing (get a real number not a "looks decent"), mark the distributor plate so you can get back to the setting that works, check the advance mechanisms by revving the engine with and without the vacuum advance hose connected, then if everything works correctly take it for a drive.

 

http://www.pertronix.com.au/assets/pdf/Pertronix_Ignitor_1_Installation_Instructions.pdf

 

"THE MODULE Always double-check, even triple-check that you have wired up the Ignitor correctly before starting your vehicle. RED wire to POSITIVE (+ve), BLACK wire to NEGATIVE (-ve). If the wires are reversed, the transistor will fail, the Ignitor will be inoperable, and the warranty will be void. An incompatible coil (refer "The Coil") may also cause the transistor to fail, by allowing too much current to pass to the unit. This situation also voids the warranty. Leaving the key in the "ON" position without having the engine running for extended periods can cause the coil to overheat, and 'cook' the Ignitor. Always ensure that the engine is running when the key is switched to "ON", otherwise use the "Accessories" position for use of other electrical components (e.g. Radio, CB, 12V source etc). A "key left on" situation is not covered by the warranty. Always be careful, as replacement modules will cost approximately 85% of a complete kit."

[NewZed]

Also - check the grounds.  The points and the Pertronix gorund through the distributor body.  It needs to be grounded well to the engine block which needs to be grounded to the battery negative.

 

And, the condenser on a points system can go bad, shorting the circuit, causing a no-spark condition.  You can check that with a meter.

 

And, also, if you have an electric fuel pump that could cause the low power problem if the carbs are running out of fuel.  Many people convert to electric fuel pumps and there are many wys to go wrong there, beside the typical crusty old Z fuel tank.  But if you get your ignition right you can forget about that and move on to fuel.  Igniton timing is easy to set and measure and confirm.

[MDZED]

Let me clarify. I’m still learning the lingo. 
 

I moved the engine to what I thought was TDC, show my timing dot around 3 degrees off 0, and the distributor rotor at roughly the 11 o’clock position to align with wire 1. I tightened the distributor down to make sure it wouldn’t rotate out of alignment.

 

In this position, the car would start and idle, I could drive the vehicle, BUT, it would die while driving.  I would get variable amounts of driving time before it died. 
 

In order to get the car started again, I would need to loosen the distributor screw and advance or retard the timing. I don’t know if this circumstantial to my issues. 
 

The gas tank is in excellent condition, it’s nice and clean inside, I have visually checked it, and the PO said it was replaced not too long ago. I can hear the fuel running, and can see gas squirt when I rotate the linkage. I really don’t think it’s a fuel issue. 
 

I didn’t get the same instructions for that Pertronix conversion in the US. Or they were missing. 
 

I made sure the ground was securely tightened with the screw provided to the plate. 
 

I will do one more check on the connections and screws and lines for the pertronix conversion. If that doesn’t work, I will reassemble the old distributor and start from there. 

[NewZed]

I would examine the movement of the breaker plate and the vacuum advance plate.  Sounds like one or the other or both might be sticking.  Changing your timing as the engine runs then sticking in the wrong spot.  Based on what you are describing.

 

Take your timing light with you and check the timing when you have problems.  If you have to reset the timing to get the engine to start but get the same number with your timing light then something has moved within the distributor.

 

I'd also watch a few videos about vacuum advance and mechanical advance.  Good luck.

 

 

[MDZED]

Thanks!  Good advice. 

[MDZED]

To close this post out. It was the gawd dag distributor condenser. 
 

The seemingly “unimportant” part (as I’ve seen in countless other research) that keeps your points from welding together also acts as a… condenser.  
 

If you’re running into an issue and you have everything there but just not getting the spark from the dizzy, check that. 
 

A $15 part and easy to fix.