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DaveT

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Posts posted by DaveT

  1. The dowel pins, I didn't remove, just work around / avoid them.  The blocks I've dealt with barely needed anything.  I just used 220 grit, and count strokes if you have to, so you don't over do one area.  Use single edge razor blades or utility knife blades perpendicular as scrapers to get the gasket junk off without shaving aluminum.

  2. No the aluminum channel is only 2" wide.  It's long enough to span the width plus a bit.  The idea is just to touch any high spot, or stuck crud.  I don't try to remove a lot of material.   Make sure you hit all areas evenly.   The ones I have done have not been bad.  The headgasket seals against the steel cylinder wall, as opposed ro the aluminum on the head side, so there should be less imprint. 

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  3. I don't remember if I've seen anyone do it with an EA82.   Since the 81 & 82 are the same displacement -
    I would think that the 2 carbs would need to be slightly smaller, because the CFM through each would be about half of what the flow through the normal setup would be.  The Hitachi carbs are a nightmare to deal with, probably better off with something you can get jets for, like webers?   From what I remember from numerous threads, the ultimate power limiter on the EA 81 & 82 is the ports in the heads.

     

  4. Those years are pretty close, they probably will work.  All of them have  a pin that tells the ECU if it is is connected to an Automatic or a standard shift.   If you have both schematics, you can find it.

    I will see if I can find some time to look at one of my spare ECUs.  A few years ago, I started to reverse engineer one.   Many of the ICs were normal parts I could find data sheets for.  Transistors, I can figure out, marked or not, I just have to trace out which one is connected to the CEL pin.

     

  5. Re. This- " With a known good bulb in and it closed-circuit, there is still ~12v on the IG side but more like 10.5 on the other side. Is this normal? "

    Ok, this [combined with the info from your open circuit test] indicates that the bulb is lit by the circuit grounding the 10.5V side of the bulb.  I have not had to trace or trouble shoot one of these to this level before, but from general electronic design experience, I figure that the ECU pin for the lamp is an open collector type drive.  That means it is open circuit until the ECU signal makes it tie to ground, maybe a few hundred millivolts would be on it in that case, and the light would be on solidly.  It is possible to blow out the transistor - if something were wired wrong, like it was tied to +12V and then the ECU tried to light the CEL.

    The other bulbs - I'm thinking you are referring to the other red lights on the dash, for alternator, brakes, etc?
    Those are not controlled by the ECU, they have their own circuits.  Some are switches, so they will read very low V on the GND side.  The alternator one, for example, is wired into part of the regulator circuit, and likely not driven as hard, so a couple volts on it is not unexpected.

     

  6. For checking the links, you are better off using a spare light bulb, like a brake light bulb.  One end to the battery - or frame, the other to each end of each link, in turn.  A volt meter is good, and all, but a bad link with a high resistance connection can show as good with no load.  The lamp test is the load.  Even better, check volts while the lamp is lit.

    You cannot test amps unless you put the meter in series with whatever load you are testing, and many loads in cars are way too high for typical amp meters, so you really want to know what you are doing before you do that, or you will need a new meter, or worse.

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