This regurgitated to the top of my mind today, and started an
argument, because I was interrupted, which derailed my train of
thought. This has to do with quite a while ago when I did alot more
car work. Generally I did not change brakes and stuff like that, I was
more of a diagnostician.

Well now I work on bigscreens, and only troubleshoot cars when it is
really bad, when all other avenues have been exhausted. One guy, even
Mr Goodwrench told him to change the engine. I found the problem, and
it was not the whole engine.

Anyway, after gong through the hoops the pickup comes to me for
diagnostic. Nissan, in the 80s, four cylinder. Now this guy is my ex
lawyer. I mean he was MY ex lawyer, so he had money. He was very
pleased with the truck and wanted to keep it. It had been around and
noboby found the cause of the problem. I and my cohorts did.

Now we all know how fun it is to follow work after someone else in
electronics, but read on and picture this. The light argument at my
house tonight was about me getting interrupted, because my mechanic
was here and I wanted him to hear this. So bear with me, I intend to
be complete and precise.

The symptom is, every once in a while, at almost random intervals the
thing would start running very bad, to where you can't drive. This
happened on the freeway, anywhere. There was no correlation expressed
to me about temperature or miles driven, in fact IIRC they told me
that it was almost independent of those factors. I was not talking to
dummies, they know things.

But they ran out of ideas and I am sure I am at least the fifth or
sixth person to try to tackle this. This was years ago. But it came
up, so I thought I would bring it up. We had to drive it around a
little bit to get it to act up. Sputterin and spitzen on two
cylinders. Now I have been in the game for a long time, but I tried
initially eliminate possible electrical causes. Spark, fuel delivery
all that, I basically rechecked, but alot of people know that drill.

My buddy was running the job. We were baffled at first but just, as
usual found out all the things it is NOT. He had the logical mind, but
this even befuddled him. I think he was getting close, but he called
me. He knew I know the guy, and just, it was time.

After making sure the engine had everything it needed to run, the
focus becomes the engine. But what kind of mechanical problem could be
intermittent ? OK, a stuck valve or something, but that would only
affect one cylinder. For a time we were thinking some kind of anti-
pollution device. But this thing still did it with any of them
disabled. Illegal to drive ? Screw that, we needed to, to find the
problem.

Well it took a few beers, but it happened. We were sitting there
bull****ting and started talking about it, my buddy said "Why does it
sound to me like it is out of time ? Everything else is there, my gut
says it is out of time" (that is not verbatim).

I said "More than that, it sounds to me just like when someone gets
the distributor off 180 degrees after they reassemble an engine, like
a headgasket job, we have all had it happen, there is a 50 50 chance".

He and I got to the point where we were thinking that the cam timing
was off, and since it had a computer, it compensated, so it was only
when certain parameters existed, that the computer couldn't
compensate, thus the problem. Having nowhere else to go we physically
checked the cam timing. It was about 10 degrees off. AHA ! we thought.
But the timing belt had just been changed several months or possibly a
year ago.

He looks, sees no damage, pretty much a perfect installation, or so we
thought. At first of course to check this you tap the starter until it
is real close, and a norrmally strong Man can turn it a bit to line
everything up.

Well the starter went a little bit past the datum place, so it is time
to turn it back a hair. I don't know the exact sequence of events,
because there were a few of us brainstorming this. But what happened
to cause the revelation was that this is a stickshift. When the wrench
went on the crank, you would need someone to put it in neutral, or
hold down the clutch pedal. Otherwise the truck moves.

He said it didn't feel right, that damper was really hard to get off
the shaft. We found out the reason.

This may be a theory, but it is damn solid, in fact I would stake my
reputation on it.

Remember the timing belt was replaced ? They lost the original METRIC
key that goes on the crank to align the gear. They replaced it with a
readily available ENGLISH key, that was a few thousandths of an inch
smaller.

I wish I had pictures. Now understand, the bottom timing pulley is an
integral part of the damper. That means that for those months, every
time a cylinder fired in that engine, it was moving. It dug an egress
sort of from the keyway, in one direction of course, and then sheared,
but not nicely.

Once sheared, the metal fragments smooshed between the shaft and bore
were solid enough to run for awhile. They held good for many many
cross state runs, all kinds of driving. But it would do this, and it
got more frequent. Go figure.

That mis-sized key pounded that crank pretty bad. My Dad was involved,
I called him in once we figured this out. He recommended that we rent
the proper stuff and regrind the crank, put the right size key in it
and just retime it accordingly. I know it can be done, but it is a big
PITA, and this truck really is no gem.

So my buddy decides, after we obtained the really correct size pin, to
braze it in.

This was discussed. With other option. which included removing the
crank for remachining, or anything like that, the value of the vehicle
did not warrant it. So we brazed the key in. Timing marks were as per
original (and stayed that way now), but the problem is that this
seriously complicates changing the front oil seal.

After figuring this out, we decided that an old, working seal that is
a bit work hardened would be better able to take the heat. After
thinking about it I agree. New rubbery ones could make a mess where
old leathery ones would just be fine. We figured if we ever had to do
the front seal, we would just burn that bridge when we came to it. But
it was good, nothing leaked.

He said something like "I got real acetylene here". And that's what it
took. But two things come to mind. In his thing (dunno what to call
it) all he has to do it make a piece of metal that fills in the gaps,
he doesn't really need a bond. Just a filler. As long as it doesn't
move. That is all that is required.

Actually the key was off about three degrees from line bore, I told
them to just force it on. Future work would requires a puller. It has
been fine ever since. I think it must have ½ million miles on it by
now.

So basically, if you are as ecstatic as I am about folliwing someone
else into something, at least you know it hppens in other fields as
well. In spades.

JURB