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[Help] New to me 240z + L28 won't idle


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I've been following this guide on carb adjustment: https://zcarguide.com/tuning-adjusting-datsun-240z-su-carburetors/

 

I can get it to start up and idle for a bit, but then it suddenly shuts off and seems to spit some gas out the SU carbs. This is with the choke on a bit:

 

 

I've had to modify / repair a lot of things on this engine to get it to even crank / start. I've bypassed the old wiring. I've tried wiring up the tach, but it seems to not work.

Is there an easy way to get the crank speed out of this setup? Is there an easy tach I can wire in instead? I'd like to go completely digital eventually.

 

240z_tach.jpg.4223939393f4200261f309fb700a2a77.jpg

 

Does anyone know why it might be idling like this and then suddenly stopping? Anything I can inspect?

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What's going on with your advance mechanisms?  Do you have vacuum advance connected?  Does the breaker plate move freely, or is it slow and sticky?    Seems like it was running well then the timing changed and it died and kicked back.

 

If vac advance is connected you might disconnect it and try again.  Turn the distributor a bit one way, then a bit the other way if you don't have a light.   You're pretty close.

 

I wouldn't worry about the tach right now, the way it ran at the end seems like it has good spark.

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I tried disconnecting the vac advance tube, but it seemed to not change anything.

 

Then when looking at the distributor position, I noticed the clamp plate isn't lined up. It looks like the distributor might be completely clocked in the wrong direction:

 

https://photos.app.goo.gl/QDTiUHLrrtCHWk838

https://photos.app.goo.gl/3xzj8eV25yt8EuWi7

I'll probably take the whole thing apart tomorrow to investigate.

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From the look at those photos,   Id be getting a timing light pretty quick! Your right in regards to that being 180 degrees out.   I can’t remember if that piece is reversible on the distributor itself or not? Perhaps the plug wires are not in the correct position and they did that to try and correct it?      
 

 

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I know I"m late to the party, but I had a similar issue when I got my first Z. It might be worth pulling off the distributor and making sure the shaft is clocked the right way, especially as it appears yours is mounted incorrectly anyway. As I recall the end of the shaft that drives the distributor has a small half and a big half divided by a slot, the small half should be on the left and the slot should be at the 11:25 position (you'll want to verify the accuracy of that with the service manual). I had to pull my oil pump (that drives the distributor) and re-clock it the correct way, it was non-running when I bought it and the person who worked on it before me got it wrong and it was 180 degrees out, sounded a lot like yours does.

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