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1G CAS install

Posted by 91Bomb, Feb 16, 2016

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  1. 91Bomb

    91Bomb Proven Member

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    I swapped my CAS with a spare when my car wouldn't start just to rule it out as the problem which it wasn't. So when I popped the original cas back in was I supposed to reset timing -or- was lining paddle wheel up correctly to notch on cas and carefully installing in same position as other cas good enough? Car seemed to run ok even though I think there's a chance it may be 180 degrees off which I'm taking to mean the notched side of paddle wheel is 180 off the notch on cas, but not even sure if that's what is meant by being 180 off so need clarification on that..
     
    Last edited: Feb 16, 2016
  2. Boomdeeze

    Boomdeeze Proven Member

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  3. steve

    steve DSM Wiseman

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    On a 1G you should always verify that the CAS timing is still 5* BTDC if you touch it.

    The notch on the blade and on the body line up at TDC. If you were sure that the notch on the blade was at the same point as it was when you took it out it should still be in the correct orientation (assuming the original was) but since the blade will engage with the CAM in two positions if you didn't verify that the notch was the same it could be correct or it could be 180* off. You still have to make sure the timing is correct since it's unlikely that the body didn't move any during the process.


    CAS.gif

    cas-linedup.jpg

    This is 180* out compared to the other picture. See where the notched end is compared to the other.

    cas-180out.jpg
     
    Last edited: Feb 16, 2016

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  4. crash

    crash Proven Member

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    That's a good write up above. You'll also want to rotate the engine to TDC before pulling the CAS off and checking. If you're off TDC there's no fireproof way of checking where the CAS is at in relation to TDC. You could look at the cam and check where the dowel is and rotate the CAS paddle to line up with it but putting the engine at TDC before you install the CAS will be 100%.

    Like Steve says, when you install it, both stud holes are elongated and the entire CAS can pivot about the center. You'll need to use a timing light to check that it is in time.
     

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  5. 91Bomb

    91Bomb Proven Member

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    Thanks for pics and that's what I thought about proper line-up and being 180 off.

    Now for timing, by setting cam gear dowel holes at 12 o'clock position + crank pulley mark lined up with 'T' does that guarantee #1 cylinder is at TDC? Is there no need to pull #1 spark plug and look for cylinder to be tdc if those other 2 steps are done?
     
    Last edited: Feb 16, 2016
  6. steve

    steve DSM Wiseman

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    The reason for pulling the spark plug is due to the common DSM problem of crank pulleys splitting so the mark on the outer ring can't be trusted. If you have a good crank pulley you can go by the mark.

    How do you know that the pulley is good? By pulling the plug and verifying the marks lines up at TDC...
     

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  7. 91Bomb

    91Bomb Proven Member

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    Ok so I'll pull the plug too.

    I'm hoping I don't have a problem identifying the timing connector because I couldn't find the fuel pump check connector awhile back and since they're both in same area worried about possibly confusing them.
     
  8. 19Eclipse90

    19Eclipse90 DSM Wiseman

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    Assuming you have a '91 as your member name suggests, you did see this about the fuel pump check connector, right?

    1g base timeing/confusing
     
  9. 91Bomb

    91Bomb Proven Member

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    I now have '93 Talon turbo.
     
  10. steve

    steve DSM Wiseman

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    Not that it turns out to be critical in this thread but you should update your profile so that there is a clue to people in future threads if you forget to be specific again.
     

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  11. 91Bomb

    91Bomb Proven Member

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    Are 91's a problem only and not '93?
     
  12. steve

    steve DSM Wiseman

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    The missing fuel pump check connector is only an issue on some 1991 cars.

    There are many differences from year to year that might apply to any given problem which is why you should always clearly state what you are working on in the initial posts to a thread.
     

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  13. 91Bomb

    91Bomb Proven Member

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    Last night I pulled CAS and it was in phase (before removing I got #1 cylinder TDC). But I did notice when my cam gear dowel pins are at 12 o'clock and screw driver on top of cylinder is all the way up, the crankshaft pulley timing mark is at 10 btdc. Is it supposed to be at 'T' mark or is 10 btdc ok?

    Also, when you put CAS in it doesn't matter if you move it a bit accidentally just before setting base timing, right? I mean I had paddle wheel lined up with notch correctly and installed it but before lightly tightening it the whole thing rotated slightly.
     
    Last edited: Feb 21, 2016
  14. steve

    steve DSM Wiseman

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    When the piston in cylinder 1 is at the top of it's stroke the crank pulley should point at the T mark on the front cover

    Time to check your crank pulley for the rubber breaking down and shifting.

    You're going to rotate the CAS housing when you set the base timing. Just don't let it move when tightening then.
     

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  15. crash

    crash Proven Member

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  16. steve

    steve DSM Wiseman

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    Unless a rod or crankshaft is bent, when the #1 piston is at the top of it's travel the crank will point to TDC.

    Either 91Bomb didn't really find TDC with the piston or the crank pulley inner hub and outer ring have separated causing the timing mark on the outer ring to move like so many 1G crank pulleys have before.

    Again assuming he really did find TDC via the piston, the cam timing marks aligning with the dowel pin up at the same point tends to confirm that the timing belt in on correctly.
     

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  17. crash

    crash Proven Member

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    That makes sense, Steve. I read it as crank sprocket instead of pulley. Although, considering the original post is for the car not starting, you think this could be a possibility? If it's jumped timing, would have to be a lot and not even sure it's possible to jump that many teeth, he could be off.

    OP, like Steve says, check your crank pulley for separation. While you have it off, verify that your crank sprocket is in time with the cams.
     

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  18. 91Bomb

    91Bomb Proven Member

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    If CS pulley rubber separated and shifted a little could the mechanical timing still be ok? If so there would be no way to set ignition timing -or- is it possible to line up timing with other marks like oil pump sprocket, cam dowel pins, etc and if everything lines up except CS pulley mark simply paint a new dot in correct spot?

    Upate: Just turned engine by hand at least 6 times and when cam gears line up the CS pulley mark is 10 btdc every time. When I rotate engine so pulley mark is at 'T' then 3/9 o'clock cam marks are off by 2 teeth and both dowel pins are slightly past 12 o'clock. Can I assume timing has jumped 1 or 2 teeth and CS pulley is probably ok since what are the chances CS rubber separated by a measure of exactly 2 teeth as shown by cams?

    (the no start issue was months ago when cas got removed to see if it was the problem which it wasn't. The reason for messing with it now was to make sure it had been correctly reinstalled and turned out it was. Now I just noticed the timing marks aren't lining up correctly upon trying to set base timing.)
     
    Last edited: Feb 22, 2016
  19. 19Eclipse90

    19Eclipse90 DSM Wiseman

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  20. 91Bomb

    91Bomb Proven Member

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    I wasn't able to inspect it closely but I'm thinking if cam gear 3/9 o'clock position is exactly 2 teeth off when CS pulley is 0 tdc then wouldn't it seem to indicate belt has skipped 1 or 2 teeth? Because what are the odds the pulley separated exactly that amount only? Either way I need to change t-belt since it's overdue and no doubt should get a new pulley.

    Thanks! Just watched video and set base timing that way. But then after disconnecting ground wire from ignition timing wire and checking again I didn't like how far advanced it looked so I set it again (no ground wire to disable ecu) and got it around 8 btdc and cam gear marks looked good there too.

    However engine is rough and obviously timing marks aren't lining up right so I'm going to get belt changed asap. I'm going to do a compression test beforehand to see if any valves got damaged. If #'s look good on a normal compression test will that be all I need to know and then proceed with timing belt job or is there anything else to check now?
     
    Last edited: Feb 22, 2016
  21. 19Eclipse90

    19Eclipse90 DSM Wiseman

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    Sounds like you're going in the right direction. If mechanical timing is off, setting ignition timing is useless. If mechanical timing is off, compression results can be skewed.

    Check and fix the mechanical timing as necessary.
     
  22. 91Bomb

    91Bomb Proven Member

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    I'm going to have a dsm shop change timing belt since it's way overdue but concerned about getting all that done and then finding out valves are bent (or worse). How should we approach this situation knowing I've been driving for awhile now with mechanical timing being off?

    I want to replace crankshaft pulley too but cost of new oem is quite high and I'm on a tight budget. Should I reuse mine if it appears good or swap in a good used oem pulley?
     
  23. 19Eclipse90

    19Eclipse90 DSM Wiseman

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    If a compression test is feasible -- and it should be since you've been driving on the questionable timing for however long -- you'll get some results. If they are low, perform a leak-down test to help determine why those numbers are low.

    I would never suggest using a crank pulley that has or appears to be separating.
     

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