Monday, October 8, 2012

AE86 Tech #86-28: Mission zero

 Let's check to be sure timing is zero.  Keeping the marks in line so that your 4AG always keeps firing.  And it's been sometime since I put anything car related.

Starting at the bottom, with the crank, the timing sprocket and oil pump have small marks.  When lined up, will let you know the piston is at TDC.

On top, the camshaft lobes should be pointing towards the opposite ends of the cylinder head.  It's a bit hard to see, but think of opposing thumbs.  If the lobes are point at each other, then  you're 180 degrees off.  Correct before going any further.

Even though the cams are pointing out, make sure they line up.  The camshaft position can also be visually checked making sure the cam gear dot (marked by white out) lines up with the bump on the backing plate.  Mine is just a tad off.

Lastly, with the lower timing belt cover and crank pulley installed, the zero can be referenced.. 

Install your distributor and make sure the rotor is facing the proper direction (towards the front, for you RWD owners) and that it is horizontal.  Any deviation from this will lead to utter doom and frustration.  Unless you are running custom timed cams.  Then slight deviation may be o.k.

Here's a little extra bit.  If you're like me and just decided to remove your distributor and crank your engine, how do you know if your engine is on the compression stroke, without taking off the front cover.  Since the crank will spin twice for every cam rotation, you have 50/50 chance of getting it right.

If you've got the stock camshafts in the engine already, just spin the motor until you see this little bugger.  This will let you know you're at the TDC compression stroke.  Then just fine tune with your crank until it's zero.  For those of you who like to use aftermarket camshafts, it's good idea to mark the camshaft with white out/paint.  To let you know the engine is in the correct position.

But what if your neighbor borrowed your last intake cam, and now you need to get the car running for saturday's show?  You know that you have a couple of 4AG exhaust cams laying around the back, can it still be used? Well Toyota has been gracious enough to leave a mark for you. 

Now i think it's about time to grab a cold drink.
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