Dolfinz

Can anyone tell me what the normal current draw for the battery should be? I have studied the wiring diagram and the white/red wire from the alternator goes to the shunt and through the fusible link to the fuse block. The white wire from the battery goes to the shunt and then also through the fusible link to the fuse block. I will pull all the fuses and try starting it again and see if the battery charges but if it doesn't I can only assume there must be a partial short to ground in the harness somewhere. Does this make sense?

It's a 1974 260z Nov 73 production I have now owned for 44 years. As I stated the alternator is new. Prior to rebuilding the motor it had no electrical issues. But, it sat outside for a year and it dealt with monsoons and heat during the rebuild process during that time. I know how to use a voltmeter and ammeter as I am an Electronic Engineer. I'm just looking for somewhere to start. Ammeter from alternator terminal to RW wire to confirm current is a start but what could be bleeding the current from there? Possibly the shunt? Isn't that the feed for the alternator gauge? Why cant I just take the output from the shunt directly to the battery and bypass any potential bleeds? I'm going to rewire the front harness myself and eliminate unnecessary wiring and get down to what's actually needed. Is this a possibility?

Well, I finally have the car running but now it appears I have an electrical issue. When the battery has a full charge the car starts just fine but the alternator gauge has a slight negative reading. After running for a bit and shutting it off, the car tries to start but since it has been running on the battery there's not enough spark. I have a brand new alternator that clearly isn't charging the battery when the car is running. Any suggestions as to what the problem could be?

I don't know how to send a PM in this forum. I believe the one I have is the longer of the two as it's probably 3-4 inches.

I seem to have misplaced one of my butterfly bolts for the air cleaner. Looking for suggestions on where I might find one. Stock motor.

So I have a stock engine in my 1974 260z with SU carbs from a 1971 240z. Is there really a significant performance difference by switching to Weber carbs and is there and difference between the Weber dual carb set up versus the triple carb set up? I'm trying to decide if it's really worth the money to change.

Well, one of you called it. There was another timing mark on the crankshaft pulley that we found after disassembling the front of the motor. We verified tdc and all mechanical timing marks where they should be, put it back together and the second timing mark was on 0 at TDC. We put everything back together after I rebuilt the carbs again and she fired right up. Problem is she won't idle on her own and after running for a bit she stalls and won't restart unless we hold the pistons in the carbs up. They are SU carbs as I pulled the Hitachi's shortly after I bought it and replaced them with the SU's. So, asking for more input. I assume I will need to adjust the fuel dials underneath the carbs so should I take them downward to allow more fuel or tighten them to restrict the fuel? Also, might I also need to make some adjustments on the linkage or tops of the carbs?

To clarify a few things. I have owned this car for 43 years. It is the first car I ever bought. The engine is original but has been rebuilt a couple of times. The timing plate has always been located on the right side of the timing chain cover when facing the engine. See the attached picture showing the mounting location. The plate has 2 mounting holes and will only mount in this location. The car had been sitting for about 5 years and I decided to get it running. When I did I took it for a drive and somehow bent a valve on the number 5 cylinder so I took it to a former friend/mechanic with the new head I bought from z car source to rebuild. He told me I probably had the mechanical timing off by a link or two and that was why I bent the valve. He said he would make sure the timing was right this time. He had a machine shop rebuild the lower end and then he put the rebuilt head on it a returned the motor to me to finish reassembling, intake, exhaust, carburetors and linkage, oil pump and distributor, alternator, starter, radiator and all fuel and coolant lines. Once assembled we couldn't get it to even try to fire so we checked for fuel, spark and compression and we had all 3. At this point I figured it had to be a timing issue and that's where we are. I personally rebuilt this motor once but it was 35 years ago. I know we are on the compression stroke at TDC because we verified it with a compression gauge in the spark plug hole prior to disassembly. As I stated previously, according to the service manual everything looks right but the timing mark on the pulley location. I assume this has to mean an issue with the timing chain but I wonder if I can't just remark the pulley at 0 on the timing plate and see if I can get it running. Problem is I hate to try something that might not work and require tearing the thing apart again. And the other thing that's baffling is it isn't 180 degrees off. Hope this helps.

I can temporarily reinstall the pulley and post a picture but as I previously stated with it correctly installed and the keyway in place the timing mark on the pulley is at 10:00. It should be on the zero on the timing plate correct? That would need to be at about 3:00. What confuses me is that's not 180 degrees out. The pulley isn't the original but I still have the original and they are exactly the same. Per the service manual everything appears to be correct except for the timing mark on the pulley. I'm baffled.

Let me know if these help. Lobes on cam appear to be correct.

Thanks for this. I will check.

In my prior statement I meant the timing mark on the pulley was at 10:00 and should be near 3 to line up with the 0 on the timing plate. The timing mark on the crankshaft itself is at 3:00 as shown in the service manual. I thought as long as the lobes were flat the valves were closed. Do they need to be sticking up like you said? I currently have the pulley and timing cover removed to verify the timing chain is correctly installed. That's what I'm trying to determine.

Thanks for the explanation.. As soon as I get the clear picture of the cam sprocket I will post and we can go from there.

What other method is there? We turned the motor to verify compression stroke and the piston was verified at TDC by using a screwdriver inserted through the spark plug hole to insure it didn't fall once it rose to it's maximum height. The lobes are flat and the crank is where the service manual timing mark shows it should be. i still question that since the lower end was rebuilt by one shop and the head was installed afterwards if the lower end wasn't 180 degrees out with the new head possibly putting the timing mark on the pulley out of alignment? Perhaps the lower end was on the compression stroke and the head was on the exhaust? I'm not a mechanic and this is confusing. I have personally rebuilt this engine 3 times and this has always been the most difficult part. Having others involved has only clouded the situation regarding the work that was done. I don't believe the damper has slipped on the pulley as I have two pulleys that are exactly the same. I really appreciate the help y'all are providing and I think we'll figure this out. Keep the ideas coming and thanks.

My question would also be that since the lower end was rebuilt couldn't the keyway have been placed 180 degrees out?

I think the question isn't the cam alignment but the crankshaft and it's associated pulley. With the crank at TDC as shown in the picture and the fact that the pulley can't install any other way due to the keyshaft doesn't that mean the the timing mark has to be in the wrong place?

Here's the thing, the crankshaft pulley and the timing mark plate are original. Another note is that with the current set up the engine doesn't even attempt to fire. Hopefully a better unobstructed picture of the cam shaft will help determine the problem. I will post as soon as I can get it.

zed head, I had to reinstall intake, exhaust, fuel lines and carbs, oil pump and distributor and all coolant related parts. TDC was confirmed on compression cycle and verified by piston height.

Can you explain the diagram further? I'm going to remove the fuel lines and provide a clearer straight on picture of the cam sprocket. Perhaps that will help.

I recently had my stock engine rebuilt. When I got it back I put the remaining parts back on and I can't get it to start. First things I checked were compression and fuel; which were good. Lastly I went to check the spark and I had spark but wanted to confirm the timing. I set the number 1 cylinder to TDC and pulled the distributor and found the shaft to be at factory spec with the small lobe forward and positioned at 11:25. I also checked the crankshaft pulley timing mark and found it to be at 10:00 and not near 3:00 as it would need to be to be at zero on the timing plate. Thus I suspected incorrect mechanical timing so I removed the timing chain cover to verify. Please review the attached pictures of the crank and cam shafts showing the timing mark locations. Per the service manual they appear to be correct, cam at 2:00 and crank at 3:00 and there are 42 chain links between them as specified. Please let me know if I'm interpreting the service manual incorrectly or any suggestions as to why the timing mark on the crankshaft pulley isn't where I think it's supposed to be. Thanks.

They had it, thanks.

I'm looking for a replacement mounting bolt that threads in to the reservoir on one end feeds through the carb and has a 6mm nut on the other behind the linkage. Please let me know of any place to obtain one.

I'm still looking for a source for the rubber boot on the manual transmission and after this past weekend's work I'm now also looking for mounting bolt for the fuel reservoir on a 240z SU carb. When tightening the nut on the 6mm end the shaft snapped. Any suggestions for either or both would be appreciated.

Thanks for the info. This confirms what I thought I remembered and is sincerely appreciated. RR