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[16v] low end torque problem found!



The first thing I would do is aim the timing light at the crank pulley
with the engine idling. Cause if you see the pulley moving at all, then
it'd be time to park the engine.
Neither the crank or the cams generate consistent torque loads on your
failed keyway. The cams can actually have torque reversal(almost like a
sin curve). So, the loads on the keyway are continually reversing
several times per revolution. I'd be suprised if a torqued crank bolt
would be able to resist this reversing load for long before it would
loosen up and let your keyway take more of a beating.
Dan

"T. Reed" wrote:
> 
> Well.. as much evidence as I had that the knock sensor system was to
> blame, it seems that is not the case.
> 
> I previously checked my cam sprocket to crank sprocket alignment and every
> time it has been dead on. Today I tried to re-time the car (ignition) but
> at full distributor rotation I couldn't even glimpse the 6 degrees mark
> in the bellhousing hole - it was on 0 degrees TDC with the distributor
> turned all the way. So I turned the engine over by hand to TDC and noted
> that the distributor was not at TDC .. the rotor was pointing a few
> degrees in the advance direction. That would be normal though because it
> changes with how much the distributor is twisted.
> 
> So now I was thinking: the mechanical part of the distributor is set
> correctly - the knock brain must be retarding it by 6 degrees all the time
> (hence I'm unable to set the timing).
> 
> This hypothesis was quickly blown out of the water when I noticed that
> while the sprockets read TDC, the flywheel mark for TDC was no where in
> sight.
> 
> I checked twice and confirmed w/ the screwdriver-down-the-spark-plug-hole
> test that my crank sprocket and flywheel are not correctly aligned.
> 
> I know why, too. The keyway on the crank that the sprocket locks in to is
> all smooshed and oversized. Despite being torqued to 175 or so ft-lbs
> around 12 months ago, the sprocket has rotated in the larger "key hole"
> and is no longer aligned with the crank as it should be.
> 
> I bought a new sprocket and bolt for it last summer and tried to make it
> work but I knew it wouldn't last forever.
> 
> By eyeballing it, it looks like I'm about 2 teeth off. I don't know
> whether that's cam retard or cam advance but I do know that I have lots of
> power up high and nothing at all down low. You do the math.
> 
> I'm not interesting in pissing away a lot of money for nothing so it's 2
> liter time, not "pull engine and replace crank" time. I need the scoop.
> What block should I use (it's 3A(?) or ABA, right?), how should I get the
> engine out of the car (I have lots of tools but no engine stands or
> hoists), do I need an exhaust manifold spacer or any other adapters, etc..
> 
> I'm also now in the market for a 2 liter shortblock in the
> Washington/Oregon/BC area. I don't want to rebuild so it's gotta be in
> good shape.
> 
> For now, I figure i'll either leave it alone or try to move the belt 2
> teeth over to compensate for the sprocket. What do you guys think?
> I don't -think- it will get any worse (ie.. more teeth off) because the
> key "hole" is only about 1.5 - 1.75 times as wide as the key in the
> sprocket. I bet it has shifted all the way over already. In that case it
> probably wouldn't hurt anything to leave it how it is (other than the
> obvious PITA to drive problem).
> 
> Exactly how many teeth do you have to jump to make valves kiss pistons?
> 
> The other thing I don't know is if the sprocket is actually loose enough
> to shift around while revving up or down. I mean.. I don't want my cam
> timing changing by a couple teeth when I downshift and then changing back
> when I step on the gas. Not that I can help it if thats the case, but I
> don't wanna try to compensate for the 2 teeth if its gonna make my head
> blow up.
> 
> ...
> 
> And as if this whole fiasco wasn't enough.. my A/C _exploded_ the other
> day!
> 
> I had it on while idling in my driveway when I heard a high pitched noise.
> Wasn't sure if it was just belts or something so I listened to see if I
> could find where it was coming from. Then I noticed that the A/C was
> blowing hot air instead of cold. I turned it on and off a couple times and
> listened to see if the compressor clutch was turning on and off. It was..
> then all the sudden the high pitched noise turned in to a squeal, then a
> screeEEEch. And **KABOOM** !! White smoke and vapor everywhere. A cloud
> enveloped the car as refrigerant and oil shot out from under my hood
> (which was up at the time). I felt like I was at one of those midnight
> Disneyland laser shows.
> 
> It was the coolest thing my car has ever done completely by its self.. and
> the most expensive (well, maybe not anymore.. stupid crank keyway).
> 
> So.. I'm pissed that I spent $55 fixing my A/C only to have it blow up
> (guess I could have used R12 and felt worse about it though) - but on the
> plus side it will get rid of all that A/C crap that takes up space under
> the hood (I have big hands) and extra weight and extra rotating mass. So
> I need non-A/C instructions and parts as well. But I want to keep my power
> steering.
> 
> I've decided to pull it rather than fix it because obviously there's stuff
> wrong with it if it blew up. I only used 2 lbs of R-134a, too. My theory
> at the moment is that something clogged the expansion valve (dirt, rust,
> old dessicant, oil globs?) and the high side pressure switch was defective
> and didn't shut off the compressor so the safety release on the
> receiver-drier blew. At least that's what it looks like. I can't tell if
> the oil all over my engine came from the drier or the pressure switches.
> They both look like the point of origin and they're in the same vicinity.
> 
> So now I've got plenty of car problems to face.. not particularly looking
> forward to any of them but I guess that's always true.
> 
> -Toby
> 
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