Leaky injectors...

[JustaxPHX@aol.com]

> So what are the symptoms of leaky injectors?

In this case, the car starts a bit rough the first thing each morning but
starts perfectly throughout the rest of the day, hot or cold.  However, when
it sits overnight, the leaky injectors drop enough gas inside the combustion
chamber to foul the plugs briefly when it's started the next morning.  I
confirmed this by pulling the spark plugs out, taping a Q-tip to a stick, then
lowering it into the combustion chamber to see whether any wetness was
present.  I found two of the cylinders had leaking injectors this way.

Of course, coolant and/or oil in the combustion chamber can cause a similar
problem but I ruled these out with by doing a leak-down test previously.

>My '89 100Q has 180K on the original ones, and my '90 90Q20V
>has 140K on them..... both seem to start and run OK, but
>recently I have noticed that my 100Q takes a few extra cranks
>to turn over though.

Based more than a decade's worth of experience with CIS-equipped cars, I can
confidently predict the injector seals and inserts, if not the injectors
themselves, are due for replacement by 100k.  Because the deterioration occurs
so slowly, it usually goes unnoticed until the car starts to run poorly.  In
fact, I've found that lazy mechanics (and cheap owners!) will often tune cars
to compensate for the minor vacuum leaks instead of tracking them down and
repairing them, which can often be very difficult to troubleshoot in the early
stages.

However, the day will eventually come that mixture is so lean, the car is
reluctant to start, and once it does, it does not perform properly, stumbling
and hesitating under acceleration, idling poorly, etc.  Of course, by this
time, it's equally as difficult to track down and repair the vacuum leaks,
usually because there are so many, no one leak is the culprit.

I believe that Scott Mo. has addressed this situation in detail at his web
site but I don't the appropriate URL's handy...

JG