[Johnthemon]

Here is a great article I found at http://www.autoeng.org

Engine analyzers come in varying sizes:

-Big box
-Hand-held

An engine analyzer should be considered one of the essential tools for any type of drive ability diagnostics, not just
intermittent. No other single piece of equipment can provide as much information about the basic function of the
engine. The engine analyzer of today is typically hand-held, versus the big box of yesterday. Although there are
some benefits to the hand-held such as portability; there are also draw backs, such as fewer features and smaller
screens. To overcome this drawback, many hand-held engine analyzers can now display directly on a PC monitor for
easier viewing and greater clarity.

Offer similar features:

-Starting and charging system tests
-Ignition system analysis
-Cylinder balance test
-Relative compression test
-Cylinder time variations

Big box or hand-held, most engine analyzers offer similar features that are helpful in diagnosing intermittent
problems. Since many drive ability related problems are still related to basics, the engine analyzer is a fast and
effective way to pin-point drive ability problems in a wide variety of areas.

Late Model Vehicles are complicated:

In the past, there were two common methods of dealing with intermittent problems. First, we could wait until the
intermittent problems becomes consistent or at least repeatable. Then we could apply standard diagnostic
techniques to solve the problem. Second, we could start at the front of the vehicle and begin changing parts until
either the problem goes away or, at the very least, becomes less of a problem. The first solution seldom works
because customers need there vehicles to be ready for the daily commutes, nor do they want to drive a vehicle with
a known problem waiting for it to break. The second solution is an even bigger problem, as the customer will end up
paying for parts that we most likely don't need. Or worse yet, the unneeded parts end up costing a customer way
too much money, therefore a good, knowledgeable auto repair shop is needed.