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When the engine warms up, it loses ignition advance! It seems that the signal from the cam position sensor is not getting to the computer, so, it defaults to no advance. It doesn’t give a “check engine” light; reading the pre-OBDII codes doesn’t show any faults. I’ve tried a new cam position sensor – no change. I’ve also groomed all the connectors related to the computer & sensors. I suspect a wiring harness issue, although the resistance readings (cold) agree with the factory manual.
Anybody know of favorite places to look for wiring issues? Or have a better diagnosis?
RoyL
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Actually, I usually get very good tool life – I still have the beam style torque wrench I bought in HS – that was in about 1966! The newer torque wrenches only come out of their cases when something has a torque specified. The problem with the sick one is that the part of the handle containing the window displaying the setting has come unbonded from the body, letting it slide around. Because of that, there’s no way to be sure what it’s actually set at.
Roy
Getting back to the original topic, I started taking the timing stuff apart today. When I went to unscrew the bolt holding the pulleys to the crankshaft, I found it was only finger tight! The basic problem was the pulleys weren’t tight, allowing them to flop around, allowing the key to munch out enough of them to make accurate timing impossible.
Evidently, when I repaired the original stripped crankshaft threads by tapping to M14x1.5, I didn’t tap deeply enough. At the time, the only tap I could get locally was a plug tap – when I tightened things during assembly, the bolt was bottoming in the incomplete threads, rather than actually clamping things together. With new parts, things fit closely enough that I couldn’t tell that the pulleys weren’t firmly clamped to the crankshaft. Now that I have a bottoming tap & know what to look for, I expect to be able to make a lasting repair.
Roy
Sounds like you’re on the path to recovery. Good luck with the tap and let us know how things turn out after you’re done.
It turns out, I’d used a bottoming tap last time. The real problem is that the bolt is a couple of mm longer than the original – just enough to let it bottom out without clamping the pulleys against the crankshaft shoulder. While I’m redoing things, I figure it’s time to replace the idlers, water pump & cam/crank oil seals.
Is there a work-around for the special tool to hold the cam sprockets while the bolt is being tightened/loosened? My first thought is chain Vise-Grips with a piece of old timing belt to protect the sprocket teeth.
http://www.irwin.com/tools/locking-tools/the-original-locking-chain-clamp
Roy
Finished!
Finally had time to get everything put back together – now it runs properly & has everything properly bolted on. I ended up buying a proper cam pulley wrench, it wasn’t worth risking damaging the pulley teeth to avoid adding another special tool to the collection 😉 I’m impressed with how nicely made & robust the tool is:
http://www.company23.com/subaru/507
Roy
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