jgautosport Posted April 3, 2008 Share Posted April 3, 2008 Hey guys , ive searched and found tons of timing issues but none like mine. I have a 77 280z stock minus headers. The cars starts right up every time, revs fine , runs smooth but this is only set by ear. When I hooked up a timing light you can literally see my crank mark walking around in slow motion for the complete rotation. I cant even get a base mark. any ideas or suggestions? Quote Link to comment Share on other sites More sharing options...
mario_82_ZXT Posted April 3, 2008 Share Posted April 3, 2008 My guess is your crank pulley/damper has come apart. If I were you I wouldn't drive it at all until you fix that. Mario Quote Link to comment Share on other sites More sharing options...
jgautosport Posted April 3, 2008 Author Share Posted April 3, 2008 My guess is your crank pulley/damper has come apart. If I were you I wouldn't drive it at all until you fix that. Mario is that something you would be able to see. Bad thing is I had it powdercoated when I was rebuilding my motor, dont know if the powdercoat is sealing anything in. Also I just noticed my dizzy bracket was powdercoated to, and Im not to sure on the ground wire there if that has anything to do with it. I sanded all the powder coat on all my ground points in the engine, too late to start it and try it (kinda loud) My cap sparks the hell out of me too when I try to adjust it, on Hondas never happend to me, is it normal? Thanks Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted April 3, 2008 Administrators Share Posted April 3, 2008 When I hooked up a timing light you can literally see my crank mark walking around in slow motion for the complete rotation. I'm with Mario on this. If timing was actually changing by a full rotation, the car would run audibly different while idling. It would quit running in a short period. is that something you would be able to see. If you were looking for it... match-mark both rear pulley's. They are isolated from each other with vulcanized rubber. If separation has begun, it will show in the match-marks. If you find that this is the case, do not continue to run the engine until you sort it out. Bad thing is I had it powdercoated when I was rebuilding my motor The temperatures powdercoating is normally done at strike me as incompatible with the isolation material. Quote Link to comment Share on other sites More sharing options...
jgautosport Posted April 3, 2008 Author Share Posted April 3, 2008 I'm with Mario on this. If timing was actually changing by a full rotation, the car would run audibly different while idling. It would quit running in a short period. If you were looking for it... match-mark both rear pulley's. They are isolated from each other with vulcanized rubber. If separation has begun, it will show in the match-marks. If you find that this is the case, do not continue to run the engine until you sort it out. The temperatures powdercoating is normally done at strike me as incompatible with the isolation material. Thanks for your input guys, ill check those things tomorrow. Quote Link to comment Share on other sites More sharing options...
jgautosport Posted April 3, 2008 Author Share Posted April 3, 2008 Well had a chance to check it out at lunch and found that when you rev the engine, (quick blip at throttle body) the damper flexes forward. Thanks for pointing me in the right direction guys , ill post results after I change it out. Quote Link to comment Share on other sites More sharing options...
jgautosport Posted April 5, 2008 Author Share Posted April 5, 2008 Something tells me you guys were right. Thanks, you guys are awesome. I ordered another pulley. Too bad its only a single drive pulley, I don't even know if my a/c works yet it but would be nice to have. Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted April 5, 2008 Administrators Share Posted April 5, 2008 Thanks for getting back to us (helps the next guy). The unfortunate reality is that the crankshaft endures a lot of stress in that situation Quote Link to comment Share on other sites More sharing options...
jgautosport Posted April 5, 2008 Author Share Posted April 5, 2008 I don't know what caused it, maybe the powdercoating temp weakened it. It was solid when I first mounted it , obviously not so much now. Thanks again Quote Link to comment Share on other sites More sharing options...
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