DIY Timing chain replacement?
Veteran
Joined: Sep 2010
Posts: 396
Likes: 2
From: Buffalo, NY
set timming which wasnt to bad but when i tested timming with 2 rotations of the crank shaft back to TDC it should still be at 12:00 which it was..... i turned it several more times just to make sure it was set right. after about 4 sets of turns 8 rotations i noticed that it wasnt at 12:00 at TDC it was at 11:59.5..... then another 8 turns it was at 11:59.
I don't see how the timing "change" is possible. Where are you looking at the marks? The primary chain drives the primary idler sprocket, and the primary idler shaft drives both cams. Did you replace ALL the chains, sprockets, and tensioners? Make sure that you ONLY turn the engine over in the direction of normal rotation, NOT BACKWARDS. If you miss your alignment point go around again. If you don't it'll place slack in the primary chain on the tensioner side and cause you to be one tooth off on your carnk - to - idler shaft relationship, which will also throw off your camshaft(s).
The "correct" way to sequence the chains is also to look for plated links on the chains and have them line up in certain spots during the sequence (outlined very well in the Haynes manual) however it is possible to have the timing marks on the gears correct and have the chains offset a link or two with no adverse effects.
Sounds like you may have installed one of the cam chains off a tooth to me.
Regarding the cam sensor, it's possible it's bad but I would check more for a broken / corroded connection on the wiring going to it. It's also possible that you're troubleshooting two different problems at once. i.e. bad timing setup AND a spark / ignition / fuel delivery / ECM problem. Start with getting the timing correct and work forward from there.
Bob