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New 73 to me wont start after 20 years of sitting. TDC?


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So a few months ago I picked up another 240z. This 73 had been sitting in a guys garage for 20 years and I'm trying to start it for the first time. When I bought it, it was missing the distributor, the seller said he had pulled it and gave it to another guy that he had sold his other 240z to. Luckily I have a rusted 73 parts car but I dont know the history of that motor, it has a L28 in it with the 73 flat top carbs, I pulled the distributor from it, dont know if it's good but there is not much to them.

 

 I Installed a new set of points, and condensor, set the gap and put the distributor onto my new 73 that I just got. This car has been changed to round top carbs and the guy I bought it from said he drove it 2 miles and parked it in the garage/barn 20 years ago and there it sat.

 

I'm getting spark from the coil and to the ends of the spark plug wires.  I dont have fuel in the car yet as I have just been spraying starting fluid in the carbs to see if it will run for 5 seconds like I have done to a bunch of 240zs in the past. but instead I just get a backfire every now and then. It almost feels like the distributor is 180 off but it only goes in one way. I set the car to TDC physically watched #1 piston come to the top using a flash light and looking through the spark plug hole.. I lined up "0" on the crankshaft to point mark. The rotor points to the #1 plug wire on the cap like it should.

 

I think I read somewhere that the cam lobes on #1 need to be facing up when it's in TDC when looking through the oil cap hole. The lobes are not up, they are at like 10 o'clock. Could the timing chain have skipped and it's so far off that it wont fire up? I'm trying to check all the simple stuff first before tearing into the motor. He said he drove it and parked it. I did not mess with the oil pump or oil pump shaft, just dropped in the new distributor. Wonder if these carbs could be so far out or gummed up that it wont even run for 5 seconds. At this point I just want it to run enough so i can drive it out of the driveway and into the back yard on it's own power doesn't have to run perfect. As I will restore the car another time. What can I check or try at this point to get her running?

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17 hours ago, 5 Star Rising said:

sitting in a guys garage for 20 years

 

17 hours ago, 5 Star Rising said:

spraying starting fluid in the carbs

 

17 hours ago, 5 Star Rising said:

almost feels like the distributor is 180 off but it only goes in one way.

 

The cylinders could be too dry to create compression.  You might squirt some oil in the cylinders and try again.  It worked for me years ago on a 63 Bonneville that had only been sitting for one year.

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17 hours ago, 5 Star Rising said:

Could the timing chain have skipped and it's so far off that it wont fire up? I'm trying to check all the simple stuff first before tearing into the motor. He said he drove it and parked it. I did not mess with the oil pump or oil pump shaft, just dropped in the new distributor. Wonder if these carbs could be so far out or gummed up that it wont even run for 5 seconds

 

Gummed up carbs seems possible.  The pistons won't come up to let air in unless there is engine vacuum.  They're not like butterfly blade carbs.

 

You could prop the pistons open a bit to let air in.  Don't squirt too much starting fluid though because it will probably rev like it's wide open.

 

p.s. timing chains almost never skip.  Very unlikely.

 

p.s. 2 - if it's really been sitting 20 years you should probably remove the valve cover and oil things up.  These engines are known for throwing rocker arms when valves get stuck after sitting for long times before restarting.  And/or destroying cam lobes.  Then you can check TDC/compression stroke too.

Edited by NewZed
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I'm going to mess with it later today. I was going to squirt some oil in the cylinders but cant find my little pump oiler can, going to find it later, pull the valve cover and oil every thing up. So the #1 cam lobe being straight up 12 o'clock while it's at TDC is not correct? Thought I read that some where but could be wrong.  I had pulled and stabbed the distributor a few times and rolled the motor by hand to make sure it wasn't on the exhaust stroke. Crank pointer at Zero, cyl#1 to top of chamber and rotor pointing at #1 spark plug wire on the cap.

 

The linkage on the round top carbs was all frozen and the they had placed aftermarket throttle springs that were are rusted and broken, the throttle screw on the front carb is missing so I have the linkage clamped together with small vise grips and added a new throttle spring. I honestly spent 15 minutes doing this, definitely not how I will fix any of the problems permanently, just trying to move the car into the backyard for now.  But maybe the carbs are really messed up... You would think it would run for 5 seconds atleast when lifting up the carb pistons and spraying starting fluid in the Intake. That's why I was still stuck on the spark issue.

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The comments above all seam valid.  I'm assuming you have rotated the distributor in both directions while having the same result.  There are several different distributor bases or "fixing plates" as the FSM calls them.  Each was designed to go with different distributors.  Using the wrong one will greatly effect timing adjustment.  Just my two cents worth based on a similar problem I had with my 280zx.     

 

Somewhere, perhaps here on hybridz or at classiczcar there is a post with a link that has photos of each base and describes to which distributor it matches up with.  I haven't been able to locate it but hopefully someone with point you to it.

Edited by Mayolives
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7 hours ago, Mayolives said:

The comments above all seam valid.  I'm assuming you have rotated the distributor in both directions while having the same result.  There are several different distributor bases or "fixing plates" as the FSM calls them.  Each was designed to go with different distributors.  Using the wrong one will greatly effect timing adjustment.  Just my two cents worth based on a similar problem I had with my 280zx.     

 

Somewhere, perhaps here on hybridz or at classiczcar there is a post with a link that has photos of each base and describes to which distributor it matches up with.  I haven't been able to locate it but hopefully someone with point you to it.

Thanks for the heads up. Yeah I'm not sure what distributor this is for. It came from a 73 240z that someone had put a L28 in. It had the stock flat top carbs installed on it so I assumed they used the stock distributor too but you never know. Could be different to fit the L28 set up I'm not sure.  Distributors are getting harder to find by these days and if you do they are pretty expensive.

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I had a similar issue as well. Backfire out of the carbs on my 1971 240z with 4 screws. I was young and dumb (still am) and when I switched out the distributor I put it back 180 off! Took a neighbor getting tired of hearing my motor trying to run on a single cylinder to come over and let me borrow a timing gun for me to find out that my timing was way off. I'm not familiar with other year model z's like your 73 so I'm not sure what type of distributor it is. Quick search gave me these results. Part number 22100-E4603 is from 7109 to 7206. 22100-N3300 is from 7207 to 7307. Here's the link: http://www.carpartsmanual.com/datsun/Z-1969-1978/electrical/distributor/240z/for-manual/from-sep-71 . Not sure how to read the part number on a dizzy to find out which one yours is. I do know that a difference between some of the distributors are how many points they have. The earlier models were single points while later model 240z had dual points (smog).  Good luck!

 

Edit: 

From 7308 to 7411 22100-N3602. Link: http://www.carpartsmanual.com/datsun/Z-1969-1978/electrical/distributor/260z

 

Edited by Alexander240z
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On 12/17/2021 at 5:45 PM, 5 Star Rising said:

I'm getting spark from the coil and to the ends of the spark plug wires.

 

On 12/17/2021 at 5:45 PM, 5 Star Rising said:

The rotor points to the #1 plug wire on the cap like it should.

 

Don't overlook simple stuff like firing order.  1-5-3-6-2-4 counterclockwise.

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