scuba steve Posted February 26, 2008 Share Posted February 26, 2008 I put an L28 into my 260Z a while back, and had it running well. I used all the 260Z accessories at the time...since then, I switched to the zx dizzy ( with 12-80 ic). It ran a little sloppy, so I checked the timing closely. It turns out there are two timing marks on my crank pully. I double checked TDC with a dial indicator in the #1 spark plug hole, and the cam lobes pointed up. The cam sprocket mark lined up with the cam tower mark. I found that the spark timing was off ALOT. I did not have enough adjustment in the dizzy mount to bring it in. I pulled the hold-down screw and kept turning the dizzy until the timing mark on the damper was 10 deg BDC (vacuum advance disabled), and the mounting plate was way off. I know I can rotate the oil pump gear to bring this in, but I wondered, why would the timing be so far off from one dizzy to another (the oil pump gear was not rotated when I switched dizzys)? I plan to re-check TDC tomorrow to verify that my cam timing is good, but this has been really bothering me, since I was rather meticulous when I set the whole thing up. Could this be a sign of the damper rotating? A little bit more info: I had to reuse the 260Z dizzy mount on the L28; I tried both the 260Z dizzy mounting plate and the 280ZX dizzy mounting plate, and could not use the adjusting screw to lock down the dizzy with either one. Quote Link to comment Share on other sites More sharing options...
TrumpetRhapsody Posted February 26, 2008 Share Posted February 26, 2008 Can you post a pic of the top of the two dizzy's without the caps on? Quote Link to comment Share on other sites More sharing options...
scuba steve Posted February 27, 2008 Author Share Posted February 27, 2008 Sure can...they'll be there late tonight or tomorrow morning. What are you looking for to be different? Quote Link to comment Share on other sites More sharing options...
Noddle Posted February 27, 2008 Share Posted February 27, 2008 when I went from point to electronic dizzy, I found that the base plate were different, i'm not sure if this is your problem or not. Nigel Quote Link to comment Share on other sites More sharing options...
scuba steve Posted February 27, 2008 Author Share Posted February 27, 2008 I noticed that the base plates had a slightly different slot relationship. I can't remember now which one I installed, but I used the one that was closer to where I needed the slots. http://www2.snapfish.com/slideshow/AlbumID=209645371/PictureID=4656481614/a=48753263_48753263/t_=48753263 The first three photos (in the car) are the ZX dizzy. Notice the 5 hp clamp holding the mounting plate in place (as the slot placement wouldn't allow me to put the screw in). The two photos over my tool box are, of course the 260Z dizzy. Quote Link to comment Share on other sites More sharing options...
scuba steve Posted February 27, 2008 Author Share Posted February 27, 2008 I just verified that the cam timing is correct. I used a dial indicator to find the absolute TDC on the #1 piston on the compression stroke, and my cam sprocket notch lines up perfectly with the indicator mark on the tower. If I read the Haynes manual correctly, this mark should be just left (right lookin at the front of the motor) of that mark!? Would it be morth my effort to switch the sprocket to the #2 locating pin? Also, I verified that the damper was not rotating, but the rubber IS deteriorating...so anyone got a good damper for a N42? I'll probably post a WTB for one too. Quote Link to comment Share on other sites More sharing options...
scuba steve Posted February 28, 2008 Author Share Posted February 28, 2008 Anyhoo, at this point I know I need to just rotate the oil pump gear, but if anyone knows why these two dizzy's are off from one another, I'm really curious. Has this happened to anyone else? Quote Link to comment Share on other sites More sharing options...
zcar74260 Posted February 15, 2009 Share Posted February 15, 2009 did the same thing on my motor just made the slot on the dizzy longer Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.