The Tuning School’s Bob Morreale.

The most important sentiment laid down by The Tuning School‘s Bob Morreale during this year’s AETC seminar provided interesting perspective. The title of Morreale’s presentation was “Beating The Clock: Is the problem in the tune, or mechanical?”

“As a tuner, we’re especially vulnerable to a physical problem on a car. Because when I sit down to tune a car, I’m going to strap it down to my dyno, and I’m going to become one with my laptop,” he says. “And that is where the problem begins. As tuners, we tend not to think outside that little box. We go down that road that ends up leading to four hours or four days or four weeks of wasted time.”

He teaches his students to live by three rules to avoid the common problem. The first rule is to begin the tuning process by looking for trends in the data. The example he showed on the monitor was a beautifully-built 2002 Camaro that presented with a pile of brand-new parts installed by a well-known, reputable local shop.

The vehicle was in his shop for a tune, but the startup, idle, and drivability were all poor. With normal tune changes to account for the new parts, and adding fuel, the startup and idle were still lean. As Morreale discussed, the normal response from a tuner is to chase the problem by performing more tuning to the vehicle, and that’s where his first rule comes into play.

Rule #1: Never make more than three corrections chasing a problem before declaring it “abnormal” and suspecting a mechanical problem with the vehicle.

According to Morreale, if the tuner is competent, after three attempts to correct the problem using conventional tuning methods, the probability of a mechanical issue with the vehicle increases substantially.

He notes that the scanner is the tuner’s best friend, as it will help to identify problems and trends that the tuner may not notice using other means. His suggestion is for the tuner to look for abnormal trends on the scanner, and to not assume that the problem is a phantom issue; instead believe it is real.

Rule #2: Trust your scanner.

“It cannot lie, but sometimes tuners skip over what seems impossible, because it must be wrong or getting bad data, and the tuner ends up with a wasted day,” he explains.

He displayed scanner results on the projector that showed the vehicle with a terrible MAP reading, pointing toward a large vacuum leak, a mechanical problem that needed to be corrected before the tuning process could continue.

Rule #3: Always start by looking at the mass airflow sensor, as it is the root of the system.

He mentioned that in a modified vehicle, the sensor has often been moved from its original placement for one reason or another, and this can cause turbulence in the intake tract, causing a poor reading and making the tuning process much more difficult.

“Use your senses. If the engine sounds flat, it is,” he says.

As the vehicle in question had a MAF that had been moved much closer to the throttle body than the factory position and was positioned prominently to bends in the intake tract, causing erratic data. With the MAF sensor in this position, it caused  the sensor to read higher than normal across the entire operating range of the engine.

To sum up, he says, “Follow your rules, but always assume there is a mechanical problem. Assume a problem with the monitoring systems, like a bad wideband oxygen sensor. Also, there can be a control system problem or issue with a computer in the car. Think outside the box, and don’t get boxed in.”