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Dumb questions
Posted by Quasi (more from Quasi) on Mon, 16 Jun 2003 08:30:29
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The present owner of my 91 (ustabe mine) is doing a head gasket/timing chain. He can't find how to set TDC. Is there not a small (1/2" diameter or so) hole through which you can see the TDC mark? I seem to recall that. However, I don't see any such port on my 94. Are there marks on the later engines' harmonic balancer? I forgot to look.
Also, we were kicking around how the electronics sense when to fire the plugs. My opinion is that you align #1 cylinder at TDC, then align the cams such that the marks align, and then install the chain. You align cams and crank and don't worry about ignition timing, because power stroke is sensed by plug ionization current (all valves closed causes compression and compression causes a change in ionization current), and TDC is sensed by the crank sensor. Therefore, if you have the cams and crank aligned properly, the engine should run. In distributor cars you also have to align the distributor properly, but again, because of plug ionization current sensing, you don't have to worry about ignition timing with the the 9000 DI. Does that sound about right?
It also occurs to us that you can't test the DI by simply removing it, installing the plugs in their boots, grounding them all, then cranking the engine to see if the plugs fire. With no ionization current sense, will the plugs fire at all in this case?
After reassembly, his engine hardly runs now, so it sounds like the timing is somehow not right. Is it possible to mess up positioning of the crank sensor or the magnet(s) that fire it?
BTW, at around 140 K miles, the balance chain sprocket teeth were almost gone.
posted by 206.175.1...
Posts in this Thread:
- Dumb questions, Quasi, Mon, 16 Jun 2003 08:30:29 <-- Viewing This Message
- Memory, Tapani, Mon, 16 Jun 2003 22:36:01
- Check your mail, Kappy, Mon, 16 Jun 2003 15:43:57
- DI sensor., Gene N , Mon, 16 Jun 2003 09:28:46
- Re: Dumb questions, Gene N , Mon, 16 Jun 2003 09:14:12
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