# Trouble starting my rebuilt Z24/D21 engine



## VETRAN (May 21, 2009)

I have a 1987 Nissan hard body truck with a Z24/D21 engine. I need help from someone who knows it from the basics up, so I'll describe my issue in as much detail as I can from start to finish. Thanks in advance for any answers you can provide.

I replaced timing chain and now it won't start, so I know I'm having timing issues. I have the factory manual and it has a good picture explaining TDC with the rotor on the 6 cylinder, but it didn't have a similar picture for the 4 cylinder. I was positive that I had the timing mark at zero, so I think that confirms that it was on the compression stroke.

I don't think I can misalign the gear or the harmonic balancer on the main crank. With the timing mark on zero, I think the key on the main crank was at 12 o'clock. And the sprocket with the center pin with the three holes on the gear was at 12 o'clock on the cam. But since it won't start I must have done something wrong.

If the number one intake is on the front left when you're facing the engine, that plug wire goes to I1 on the distributor cap. It's difficult to confirm TDC with the rotor button having two brass contacts. I can't adjust the distributor enough, even with the bolts out, to get it to start. It appears I have to take the oil pump out to adjust the distributor one gear because the distributor and gear extension can only fit together one way.

I have pictures to show rotor button position. Should the outside contact of the rotor button be pointing to intake 1, or should it be the inside contact? Numbers 1 and 4 are TDC at the same time. Does that mean that number 4 is on the exhaust stroke? Also, can someone confirm number 1 cylinder/plug (when you're standing in front of the radiator, facing the engine) with number 4 being back by the firewall?

Also also, when I turn the distributor, I can hear a relay clicking. Can that be helpful to confirm anything?

Thanks again for reading and for your help! This has me really stuck right now.


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## Atomus (Mar 15, 2016)

I had the exact same thing happen to me. 

Timing the cam with the crank is easily done. By insuring the punch on the crank and the cam sprockets line up with the two different colored links on the chain. Yes, the crank should be at 12'oclock on compression stroke when installing a new chain. if you think the crank and cam are off drop the oil pan take a mirror and turn the crank till you see the punch at the crank sprocket, confirm a different colored link is positioned over or under the punch mark. Then go to the top and remove the valve cover, confirm the punch at the sprocket is in line with the colored link. 

Putting the distributor in was a pain because I didn't have a tool that reads degrees. This is what i did. The distributor is keyed with the spindle and the rotor button. rotor button should fall at #1 plug on the distributor cap, assuming you are at TDC. Use the picture in your manual as a guide at first to identify the position of the spindle, mark this position with black Sharpe. bolt you distributor centered. turn over the truck. take a timing light if you dont have to advance of retard the distributor to much you ok. If you have to advance or retard the distributor to the point it cant turn any more and you still out of timing your off a tooth or two. Put the engine on TDC, remove the distributor, remove oil pump, have a buddy make sure your spindle isn't on your black sharpe mark you placed earlier and place a new mark. Took me 5-6 trys. 

Note: To time the crank pull #1 plug stick your finger in the hole turn the crank till compressed air comes out then make sure the point on the timing cover lines up with the second from last notch on crank pulley, read the book to confirm this.

cylinders: distributor:

4 3 1
3 4 2 turns counterclockwise
2 ------>
1
Front of engine


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## VETRAN (May 21, 2009)

Thanks for the response. It helped a little, but it looks like I need more help than I realized in my initial posting.

I have a lot more information to request help with, but first I need to clarify some new developments. I have another 1986 and a half HB, which is red. The one I'm working on is blue, so going forward for the sake of clarification, when I reference Red or Blue, it's referencing the truck in question. Red for my reference truck, Blue for my work-in-progress. So to expand on that, Red has injector issues. It was running until fuel issues came up, but I can use it as a reference for TDC and firing order.

That explanation out of the way, back to Blue. You said to check the punch marks on the crank and cam with the different links. I didn't know about the different colored links when I put the chain on. I can't drop the oil pan far enough to see anything. If I did, I would have to replace the oil pan gasket which could involve removing the entire engine. I can confirm compression on the number one intake thanks to Red as my reference point; I watched the compression climb as the mark on the flywheel reached TDC. With that information determined from Red, on Blue, I can easily pull the valve cover off if needed to check alignment of the cam to see that the center of the three holes (the second hole) on the cam gear is at 12 o'clock.

When I was putting Blue's engine back together, I didn't realize until I had everything reassembled that the alignment of the colored links mattered. There's no picture in the factory manual to help with the four cylinder engine; there's only a picture to help with the six cylinder engine. That said, I think I confirmed where the rotor button should be pointing to TDC by using Red.

I'll admit I don't understand your final sentence. Are you specifying firing order as the distributor turns counter-clockwise?

Here's the new information, starting with the firing order (as I understand it) on Red (which, again, I'm using as a reference/test).

Starting at TDC: I1, I3, I4, I2, which uses the outside contact on the rotor button. With TDC intake 1, the exhaust starts at E4, E2, E1, E3.

So, I think the next step for Blue will be to put it at TDC, confirm with compression, and pull the distributor, the spindle, and the oil pump. After that, I'll put the spindle in (it turns clockwise as you seat it) while my buddy turns the distributor to lock the two halves together on the spindle. If I1 on the rotor button is pointing at the distributor cap's I1 spark plug, then I can put the oil pump back in to lock everything in place. The last step should be to pull the valve cover off and confirm the sprocket alignment is at the 12 o'clock position with the center hole and the cam pin.

Does it seem like I'm on the right path?

P.S. If it's necessary to take the cam sprocket off and rotate the chain one link, where can I purchase the factory timing-chain holder? I'd need it so the tensioner doesn't put slack in the chain again, making it necessary to disassemble the entire front of the engine...again. If I'd had that tool to begin with, I wouldn't be having many of these troubles now.


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## Atomus (Mar 15, 2016)

The firing order thing didn't come out right. 

You have to confirm the crank and cam are clocked. You don't have to pull the engine to drop the oil pan just remove the cross bar below it. A gasket runs $20 and it's worth replacing for piece of mind. Do you have colored links on your chain? They should be gunmetal or dark metallic blue color. drop the oil pan take a mirror and turn the crank till you see the punch at the crank sprocket, confirm a different colored link is positioned over or under the punch mark. Then go to the top and remove the valve cover, confirm the punch at the sprocket is in line with the colored link. If you cant confirm it this way...... remove the timing cover and put the chain on again, this time put the colored links over the punch mark on both sprockets. With out spark plugs in the cylinder head turn the crank shaft to insure there isn't any resistance (valves hitting pistons). If all is good put it back together. Then turn the crank pulley while your finger is in the #1 spark plug hole. when you hear or fell pressure coming out look at the crank shaft pulley and line up the needle protruding from the timing cover with the notch on the crank pulley putting the ka24e Engine on TDC.

Take your oil pump and put the spindle in it and install the oil pump, at this point the distributor hasn't been installed yet. Mark the position of the spindle inside the hole with black Sharpe. i under stand you have another truck/car to refer to but if you 1 tooth out your not going to know buy looking at old Red. Bolt your distributor centered of the mounting plate on the timing cover you may have to turn the rotor button to fit the distributor shaft with the keyed slot on the spindle. At this point your on TDC at the crankshaft pulley, Id like to note the flywheel is located at the back of the engine behind the transmission. Identify where the #1 plug goes on the distributor cap. Does the contact on the rotor button come in contact with the #1 contact in the distributor cap? If it does button all that up put spark plugs back in and turn over the truck. did it turn over? if it did take a timing light and if you dont have to advance of retard the distributor to much your ok. If you have to advance or retard the distributor to the point it cant turn any more and your still out of timing your off a tooth or two. Put the engine on TDC, remove the distributor, remove oil pump. Take your oil pump and put the spindle in it and install the oil pump, at this point the distributor hasn't been installed yet. Mark the position of the new spindle location inside the hole with black Sharpe have a buddy make sure your spindle isn't on your black sharpe mark you placed earlier and place a new mark. Bolt your distributor centered of the mounting plate on the timing cover you may have to turn the rotor button to fit the distributor shaft with the keyed slot on the spindle. Repeat steps above untill your timed right if you cant get it cranked must not be a timing issue.


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## VETRAN (May 21, 2009)

I don't think I can drop the cross bar on a 4 wheel drive. ..


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