Alright, I've got a 99 ex coupe with a d16z6 swapped into it. Chipped p28 with a stock z6 map (not a basemap).

In order to run my y8 PS and Alt, I had to reuse my y8 crank pulley. I scribed the z6 timing marks onto the y8 crank pulley to set timing, but it didnt work, still misses a bit at idle, and anything over 3500rpms has break ups

I've got it timed to where it runs fairly smooth, but am still getting the breakup.

Could this be a result of bad fuel injectors? Maybe a corrupt or inaccurate map on the chip?

I'm at a complete loss. With all that we've done so far it's apparent that the problem does not lie in the timing, but more likely, the fuel system. I've got perfect stock fuel pressure (have a guage).

ANy thoughts or suggestions? I'd really like for this car to run properly, since it hasn't done so in months.

Thanks in advance, and sorry for the long winded post, just trying to be as detailed as possible

 

another question, are the y8 and z6 pulleys the same physical size?

 

No ones got any imput eh?


...that seems to be the general consensus everywhere I look

 

dizzy? spark plugs might be something stupid

 

Not to burst your bubble but if i had a 99-00 civic (which I do) I would never have put in a 12+ year old engine when you could have gotten a Y8 for $300

I remember helping you a few months ago too, with the timing and the intake mani, maybe you should start looking for a Y8, there so common and cheap it's not worth fixing that POS z6 that you have been working on for months.

just a thought...


anyway your beaking up/misfiring sounds like an ignition related problem, find a dizzy from a friend and swap it

 

I didnt have much choice in the matter. This was the only motor I could find within reasonable distance, because no one was willing to ship a motor, for whatever reason..

I should also add that the Dizzy has to be turned almost all the way towards the firewall for it to run as smooth as it does right now. It is my understanding that it should almost always be right in the middle somewhere.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sicones &raquo;</TD></TR><TR><TD CLASS="quote">
I remember helping you a few months ago too, with the timing and the intake mani, maybe you should start looking for a Y8, there so common and cheap it's not worth fixing that POS z6 that you have been working on for months.

just a thought...


anyway your beaking up/misfiring sounds like an ignition related problem, find a dizzy from a friend and swap it</TD></TR></TABLE>

++2 did you do what was suggested to put the z6 pulley back on adjust the timing with it then change back over to the y8 pulley? heck for the short time you are running the car to check the timing you don't even need to put the accessory belts back on

 

I did not switch the pulleys, I scribed the z6 timing marks into the y8 pulley. THEE ONLY WAY that it would not work going that route, is if the z6 and y8 pulleys were different diameters.

Even if that is the case, the dizzy would still be in the same position it is now to achieve optimal timing, no?

Seems to me that the dizzy should sit more towards the middle, not damn near all the way towards the firewall. And no matter what pulley is on there, its going to be in the same damn spot for the motor to run smooth.

Maybe I'm dead wrong

 

It sounds like you are a tooth off on the timing belt. by your logic if the pully is larger in dia between the 2 then that would have an effect on the timing esp if you used the y8 to check the tdc on the motor if the belt was off 1 tooth then it is going to throw the timing off. If the timing is off that little bit at the start then it is going to be off when you try to advance or retard the timing. Do yourself a favor put the motor at tdc for #1 cylinder with the y8 then change the pully to the z6 I bet that your timing is off. If I am wrong then I am wrong but if I am right your problem could be fixed

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Forty04 &raquo;</TD></TR><TR><TD CLASS="quote">I did not switch the pulleys, I scribed the z6 timing marks into the y8 pulley. THEE ONLY WAY that it would not work going that route, is if the z6 and y8 pulleys were different diameters.

Even if that is the case, the dizzy would still be in the same position it is now to achieve optimal timing, no?

Seems to me that the dizzy should sit more towards the middle, not damn near all the way towards the firewall. And no matter what pulley is on there, its going to be in the same damn spot for the motor to run smooth.

Maybe I'm dead wrong</TD></TR></TABLE>

The Z6 and Y8 pulleys should be identical - the keyway is the same, so the timing marks should all be the same.

Diameter wouldn't be related to anything as the timing belt is turned by the timing gear, not the crank pulley - it's only used for accessories.

And if you can't set ignition timing correctly, your cam is a tooth or two off. Move the belt whichever direction you would need to get the dizzy towards the center.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by shifty35 &raquo;</TD></TR><TR><TD CLASS="quote">

The Z6 and Y8 pulleys should be identical - the keyway is the same, so the timing marks should all be the same.

Diameter wouldn't be related to anything as the timing belt is turned by the timing gear, not the crank pulley - it's only used for accessories.

And if you can't set ignition timing correctly, your cam is a tooth or two off. Move the belt whichever direction you would need to get the dizzy towards the center.</TD></TR></TABLE>
you are right the timing gear on the crank is what turns the the belt but what gives the reference for the position of the timing of the crank relative to the cam are the timing indicator marks on the crank pulley and the timing marks on the cam pulley. If both pulleys were identical in there timing marks then he would not have needed to mark the y8 pulley with the timing marks of the z6 pulley. As far as a difference in dia of the 2 pulleys I have no Idea I don't have them to compare. We have told the OP before and it sounds like he still has things off a bit. Oh and by the way if the dia of the pulley is larger or smaller it would have a direct effect on the timing because the timing marks are on the pulley

 

He stated the CRANK pulley was larger, they only drive ac/ps/alt. Not the timing belt pulley. They are NOT the same thing.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jay_Sensing &raquo;</TD></TR><TR><TD CLASS="quote">He stated the CRANK pulley was larger, they only drive ac/ps/alt. Not the timing belt pulley. They are NOT the same thing.</TD></TR></TABLE>

no kidding they are different. WHERE are your timing reference marks? They are on the crank pulley right? so again if the dia of the crank pulley is LARGER the timing marks are going to be in a different spot on the y8 pulley then they are on the z6 pulley. So if the OP set the crank at tdc for #1 cylinder the pulley for the cam is going to not be at TDC for #1 it will be advanced or retarded a tooth or 2 from tdc. In turn that means that the distributor would have to be advanced or retarded more to try and bring the timing into spec and more then likely there is not going to be enough adjustment and the engine is going to run like crap. So if this is the case op would have to install the z6 pulley set things to tdc for the #1 cylinder make sure the cam was at tdc for #1 cylinder adjust the timing a tooth or 2 os the cam and crank are timed correctly. start the car adjust the distributor to advance the timing to factory spec. Then he could then remove the pulley install the y8 back on the car to hook up the accessories and not need to worry about any of the marks on the y8 pulley. However if he did any service work as far as timing belt replacement or valve adjustment he would have to put the z6 pulley back on to make sure timing was set right after the repair.


Modified by instructor74 at 10:22 AM 6/4/2007

 

Ah, well the Y8's timing marks should be at 12* BTDC and the Z6 would have marks at 16* BTDC - that should be the only real difference. With a digital advance timing light, it wouldn't be too hard to compensate for, just set it at 16 and aim for the white line...

 

The timing belt has never been taken off of this motor, so I doubt being "off a tooth or two" is the case. The ONLY thing that was ever removed from this car was the crank pulley itself. I was under the impression that if it was off a tooth, that the car would be basically undriveable, if it even started..

When I set it to TDC the first time, I used the "stick trick" as I had a feeling my timing marks would be off. I gently set a long peice of dowel wood in the spark plug hole on top of piston #1, turned the crank until the stick reached it's highest point, then compared the marks on the crank pulley and cam gear, they were in spec.

The only ideas I have right now are...

- Trying some NGK wires as I have basic ones in there right now. When I switched from crappy temporary plugs to NGKs it cleared up a lot of my missing, maybe the wires will help?

- Borrowing a Virgin p28 to see if its a map issue..

- Trying a different set of injectors, as the ones I have now are off of a very old motor..

Other than that, I'm a loss

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by shifty35 &raquo;</TD></TR><TR><TD CLASS="quote">Ah, well the Y8's timing marks should be at 12* BTDC and the Z6 would have marks at 16* BTDC - that should be the only real difference. With a digital advance timing light, it wouldn't be too hard to compensate for, just set it at 16 and aim for the white line...</TD></TR></TABLE>

That's part of the issue.. I can't get it all the way to 16*btdc because I can't turn the dizzy that far. When the dizzy is maxxed out (all the way towards the firewall) it misses like crazy throughout the rpms.. I have to tap it back towards the front bumper a bit (not even 1/4") to smooth it out.

That is what led me to believe that z6 and y8 pulleys are not the same size. If the z6 is smaller like I think it is, than the 16* mark would be around the same area as the 12*ish mark on the y8.

 

the outer diameter size will NOT change the position of the timing marks, if you properly etched the timing marks on the Y8 pulley while the Z6 was sittting right on top then you should have no problem timing the motor

 

sounds to me like your timing is off a tooth are u positive everything is all lined up

 

I will pull the timing cover off again today and take some pics, but I am 99% sure it's good.

Like I said, its never had the timing belt taken off of it at least to my knowledge. It should still be in factory position.

sicones, isn't 0-16* of a 2" circle a smaller gap than 0-16* on a 4" circle? It's too early in the morning for this type of thought...

 

size or diameter will not matter because the timing mark will always land in the same position

 

I don't think thats true man... Check this out

http://en.wikipedia.org/wiki/Arc_(geometry)

Distance "L" is going to be dependant on the outer diameter of the circle. Lets call the upper arrowed line A, and lower arrowed line B. From the point where line A meets the outer diameter, to where line B meets the outer diameter is going to be our TDC to 16* Distance. 16* on a 4" circle will not have the same "distance L" as 16* on a 6" circle.

You see where I'm going with this? Thats why I can't time it using my scribed marks, because the pulleys are obviously different diameters, putting the 16* mark in a place that probably represents closer to 19*-20*

 

You are correct that the arc length will be longer, but it works because the angular velocity is the same.

Think of a wheel / tire. The length of an arc on the tire will be greater than an arc of the same angle on the wheel - but if the whole thing is spinning at the same speed, then both distances travel in the same amount of time.

I promise, this makes perfect sense in my head.

 

AAaaahhhhh!!!! That is the first thing that has made sense to me since I got into this whole mess, Thank you!

So, back to the drawing board. Wires? Ecu? New Grounds? Injectors (could it even be fuel related?)?

 

Also, would matching my timing gear to my Crank pulley do anything? The z6 timing gear is on there right now, would putting the y8 one on change things?

 

put them side by side and see if the TDC mark is in the same place...