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Timing belt

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Old 11-10-2014 | 02:00 PM
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Z Pal's Avatar
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From: Bozeman, MT
Timing belt

So, i have a 1984 N/A, 2 + 2, auto transmission, the odometer stopped at about 47K and I've put about 5K on it and I am trying to do the 60K maintenance on it. I'm the second owner, my ex-wife was the PO. I bought the 60K kit from Courtesy Parts and proceeded to do it. When I got the timing belt covers off, I noticed the crankshaft marker was in the wrong place, it was at the 6 o'clock position. The other camshaft markers were in the correct position and the distributor was at the Number 1 TDC. I removed the old belt and rotated the camshaft marker counterclockwise to it's correct alignment. Now, I'm wondering if I did the correct thing or not. The FSM says not to do this but I figured the belt had slipped a couple of notches. The old belt was in good condition. It ran fine before I did this. What do you think?
Old 11-10-2014 | 05:46 PM
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Well, if the car was 'running right' before your tune up, you should have left the marks where they were, slipped the old belt off and the new belt on... I can't imagine a belt so loose that it 'skips' notches - but I see that referred to a lot here and elsewhere on the net. If that happens, you should sense it immediately in performance. So how was the performance before you took off the timing belt cover - and how is it now?
Old 11-11-2014 | 05:16 AM
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From: Bozeman, MT
The performance was good, no problems. I haven't yet put on the new belt, I'm still working on taking off all the stuff to get to the valve covers so I can loosen the rocker shaft bolts as described in the FSM. So, it would be no problem to rotate the timing mark on the crankshaft a bit back to the 6 o'clock position it was in before I took the old belt off but then the alignment wouldn't be correct according to the FSM. So, this is my perplexing situation. I could set it at the original position or I could set it at the the correct alignment and rotate by hand and see if there is any binding.
Old 11-11-2014 | 06:08 PM
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I think you could try it out in the 'new' position - but you can't argue with the success in the old one. The last time I switched out the belt in my '86na, I noticed that the original factory mark on the crankshaft was a painted red line - but someone (at the factory, I assume) put another mark in yellow crayon about an inch to the left of the red line. That's where the old belt was set so that's what I followed. So the original factory marks may not be final after all. Maybe someone had a bad hair day in Yokohama and misaligned the crankshaft... Please let us know what the deal is with your crankshaft and belt.

Last edited by zxguy1986; 11-11-2014 at 06:23 PM.
Old 01-04-2015 | 01:03 PM
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From: Bozeman, MT
So, I finally finished with getting the timing belt installation on X-mas eve. I set the crankshaft timing mark at the factory 4:00 position. Now, I have an engine hesitation problem that wasn't there before. I sprayed the Idle Air Valve with break cleaner before I installed it, I wonder if it could be sticking. I also gapped and installed new NGK spark plugs. Also, the Fast Idle Valve doesn't seem to be working anymore, I removed it. I'll clean the connector and see if that helps. I think I'll disconnect the Idle Air Valve and run it to see if the idle improves. It's missing once and awhile and it ran good before. I disconnected alot of vacuum hoses, belts, TPS, EGR, spark plug boots, so I'll have to check everything again.

Last edited by Z Pal; 01-04-2015 at 01:23 PM.
Old 01-04-2015 | 01:35 PM
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From: east KS
where's your ignition timing set ?
Old 01-04-2015 | 08:46 PM
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From: A Shady Tree in Boise
never rotate

You never rotate a part after the belt is off, you get the marks on before that, then make sure you don't move anything before the new belt goes on, helps to add some marks to the old belt and pulleys where they line up, make sure the engine won't spin from compression by wedging the pulleys, if you were lucky enough to get the cams and crank in timing you need to pull the alternator and get it in the right position now, most likely off by a few teeth at least
Old 01-04-2015 | 08:50 PM
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From: A Shady Tree in Boise
Vacuum lines

The vacuum lines if you look close have color codes painted on them
, like a double green line, the service manual is keyed to these colors and should help get them all back in the right place, normally when taking apart the top end I label all the hoses with some masking tape, and take a lot of detail pics, will help when you get lost... at least it has helped me figure out the under hood puzzle
Old 01-08-2015 | 10:11 PM
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From: Bozeman, MT
Originally Posted by 86tcoupe
where's your ignition timing set ?
I checked my timing and my timing was set at 5 degree's, I didn't check before I set the camshaft to the 4:00 position. I probably should have. When I set the timing to 20 degree's the hesitation stopped and it is running smoothly with more pep. Thanks for the idea.
Old 01-09-2015 | 10:15 AM
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From: Bozeman, MT
Originally Posted by PredatorZ
You never rotate a part after the belt is off, you get the marks on before that, then make sure you don't move anything before the new belt goes on, helps to add some marks to the old belt and pulleys where they line up, make sure the engine won't spin from compression by wedging the pulleys, if you were lucky enough to get the cams and crank in timing you need to pull the alternator and get it in the right position now, most likely off by a few teeth at least
I know I took a chance when I rotated the camshaft with the belt off but I figure we're working on old engines and a lot has happened since it left the factory. The idler tensioner nut was fairly easy to take off, that led me to believe the tension on the belt was incorrect and that the belt could have slipped over time and that was what I was seeing with the camshaft mark at the 6:00 position instead of the 4:00 position. So, putting my faith in the factory spec's, I rotated the camshaft counterclockwise to the 4:00 position. When I ran the engine it had an occasional misfire, taking 86tcoupe's advice, I read the timing and found that it was 5 degree's. Then I rotated the distributor until it was 20 degree's. It's running good now, hesitation's gone, throttle response is improved.
Old 01-09-2015 | 12:56 PM
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Good job!

What's cool is your difference between 6:00 and 4:00 is exactly the same difference between the factory mark on my '86na and the yellow mark somebody added afterwards. Like I said,we followed the new yellow mark and the timing is perfect. I wonder how the factory mark got to be wrong at some point...
Old 01-09-2015 | 03:35 PM
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From: Bozeman, MT
Originally Posted by zxguy1986
Good job!

What's cool is your difference between 6:00 and 4:00 is exactly the same difference between the factory mark on my '86na and the yellow mark somebody added afterwards. Like I said,we followed the new yellow mark and the timing is perfect. I wonder how the factory mark got to be wrong at some point...
There is a little cut out on the lip just shy of the 6:00 position, I thought it was just a machine mark. I had to rotate the distributor almost to the end. The distributor had been more to the center.

Last edited by Z Pal; 01-09-2015 at 04:36 PM.
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