My ef has a new jdm Sohc zc block, with a y8 head and a d16z6 distributor, intake and cam gear. It’s converted to obd1 with a p28.

I have the distributor as far advanced as it can be, but it barely makes it to the tdc mark, I’ve checked multiple times if the timing belt skipped a tooth, even had a more knowledgeable Honda guy come and fix the timing belt.

still will not advance past tdc. Car runs and sounds relatively normal. Have no idea what to do

 

Which motor of timing belt did you use?

 

I’m not sure to be honest. I’ll ask the previous owner. I just know the cam gear is a d16z6

 

I moved it a tooth and with the distributor retarded as far as it was go I was able to get it to the middle mark. But when the mechanic came he said the gear was off and put it back to how it was before. Now it won’t advance past tdc again

 

Another update. Talked to the previous owner. It’s a y8 cam with a z6 cam gear and z6 timing belt

 

Seems as though I need to by an adjustable y8 cam gear to fix the issue

 

You need a d15b7 distributor for a y7/y8 head.

 

seems like I misunderstood. It has a y8 distributor wired to work on the obd1. Will that work?

 

Yes if you've done it right. You need to be sure it's a y8 cam, use a y7/y8 cam gear and check the mechanical timing.

 

UPDATE:
it’s a y8 distributor, the conversion on the harness is done, and it runs. Does this mean I can use the y8 dizzy with no other alterations?

from my understanding Sohc zc blocks deck height is 212. Same as y8. So I should just be able to swap the z6 cam gear for a y8 cam gear non adjustable and all my problems should be solved?

 

its a y8 cam

 

Another update. Switched to a non adjustable y8 cam gear. It helped a little as I am now able to get to 6 ish degrees instead of 0 with distributor fully advanced. No idea where to go from here. It’s as if it’s off a half tooth

 

You’re right with the D16Y8 cam gear if it’s a D16Y8 cylinder head and camshaft, I believe.
For crankshaft pulleys, I’m under the impression that the crankshaft pulley is supposed to be the same type as the cam gear/cylinder head, so if you’re using a D16Y8 cam/cam gear/cylinder head, then use a D16Y8 crankshaft pulley:

Quote:
d16z6 btdc is at 16*
d16y7 btdc is at 12*

use the timing marks from the actual z6 crank pulley to adjust your ignition timing.
i have a z6 head, a y8 block and a z6 crank pulley.
my timing is set at 16* btcd

https://www.d-series.org/threads/d16...7-block.98559/
End quote

Hopefully someone can confirm that.

 

I believe this is your problem. You have an OBD1 distributor on an OBD2 camshaft. I'm pretty confident based on the cam gears being half a tooth off (for a 12 degree vs 16 degree) timing, that the distributor reference is also off the half a tooth for the same 12 degree vs 16 degree timing.

I believe that is why on the mini-me and they put the obd2 head on the obd1 block they swapped the cam gear to the opposite, so you need to put the D16Z6 cam gear on the Y8 head to adjust for the half tooth. I believe you will need to transfer the timing marks over from the Y8 gear to the Z6 gear to be able to TDC the cam gear properly if I remember correctly. This should also put the cam into 16 degree timing and allow your dizzy to work in proper range.

Check the FAQ sticky and goto the mini-me section and look for OBD2 head on OBD1 block and you will see the the reference to swapping cam gears there.

How ever, reading rest of the thread... if you have a Y8 dizzy that has been repinned to OBD1 connectors properly then you want to keep your Y8 cam gear. However it's still going to be struggling because the Y8 uses 12 degree timing, while the ZC will likely be the 16 degree timing of OBD1.

What model is the distributor? TD42U? Or something else?

 

I think ignition timing is dictated based on ECU so OBD1 ECU requires 16* BTDC while OBD2 requires 12* BTDC.

 

Just to add some additional info. I believe when running an obd1 ecu on an obd2 based engine, the crank pulley needs to reflect the 16* btdc timing marks as well as the cam gear needs to reflect 16* btdc marks IF you are having to use the opposite cam gear to make up for the half tooth variance from the shorter deck height.

In this case, it sounds like deck height is already appropriate for an OBD2 setup, so it may just be a crank pully marking change that is needed to run an OBD1 ECU. I have not actually compared lobe peaks between the obd1 and obd2 cams to see if the half tooth variance correlates directly with the 4 degree ignition timing difference between the two systems. I suspect it does but have never confirmed. Nor have I confirmed if the distributor slots also have the half a tooth variance. These are two things that may play an important role in your situation.

 

Thanks for clarifying that TomCat39.

 

[QUOTE=highschooler;52586760]You’re right with the D16Y8 cam gear if it’s a D16Y8 cylinder head and camshaft, I believe.
For crankshaft pulleys, I’m under the impression that the crankshaft pulley is supposed to be the same type as the cam gear/cylinder head, so if you’re using a D16Y8 cam/cam gear/cylinder head, then use a D16Y8 crankshaft pulley.

^^^
What you said would make sense to do. Using the appropriate parts (Y8 dist., Y8 gear, Z6/Y7/Y8 104 tooth belt and Y8 pulley) that match the head and cam. With all having correct timing marks. Deck height is the same between the zc and Y8.
So I agree with getting a y8 pulley that has the correct timing marks should solve his problem.
If it was timing was still off, I would suspect something with the distributor because the mechanical timing should be correct.