Performance Diagnostics

Engine Performance • Data Analysis • Rolling Road Diagnosis

Find the Problem Before Changing the Calibration

When an engine isn't performing correctly, changing the ECU calibration isn't the place to start.

Poor performance can result from mechanical, electrical, fuelling, ignition, boost-control or engine-management problems. A fault code may provide useful information, but it doesn't necessarily identify the component responsible for the fault.

At TuningWorx, performance diagnosis is based on testing and measurement rather than replacing parts until the problem disappears.

This is particularly important before engine calibration. A remap cannot repair a mechanical or electronic fault.

Performance Problems We Investigate

Performance faults don't always produce a warning light or diagnostic trouble code.

We investigate problems including:

Loss of power
Misfires
Hesitation
Flat spots
Poor throttle response
Boost-control problems
Difficult starting
Poor idle quality
Excessive fuel consumption
Fuel delivery problems
Ignition problems
Intermittent faults
Performance problems occurring only under load

The testing required depends on the symptoms and the vehicle.

Manufacturer-Level Diagnostics

TuningWorx has access to professional and manufacturer-level diagnostic equipment for a wide range of vehicles.

Manufacturer diagnostic systems can provide functions and information that aren't necessarily available through generic diagnostic equipment, including detailed live data, system tests, adaptations and control-unit information.

This allows the electronic systems to be investigated alongside the mechanical operation of the engine.

PicoScope Oscilloscope Diagnosis

An automotive oscilloscope allows us to see electrical signals that a conventional multimeter or diagnostic scanner cannot show.

Depending on the fault, PicoScope testing can be used to examine:

Crankshaft and camshaft signals
Injector operation
Ignition signals
Sensor outputs
Actuator control
Power supplies and grounds
Communication signals
Relative compression

Waveform analysis can be particularly valuable when investigating intermittent or high-speed electrical events.

Engine Condition Testing

Before investigating calibration as the cause of poor performance, the basic condition of the engine may need to be established.

Depending on the symptoms, testing can include:

Compression testing
Relative compression testing
Leak-down testing
Fuel-pressure testing
Ignition-system assessment
Intake and vacuum testing
Injector assessment

This helps separate a mechanical or fuel-system problem from an electronic or calibration issue.

Diagnostics Under Load

Some of the most difficult performance problems only occur when the engine is working hard.

An engine may idle perfectly in the workshop but misfire, lose fuel pressure, suffer ignition breakdown or fail to control boost correctly under load.

Our in-house rolling road provides a controlled environment in which suitable faults can be reproduced while vehicle and engine data are monitored.

This can be particularly useful for investigating problems that cannot be reproduced during stationary workshop testing.

Air/Fuel Ratio Measurement

Wideband oxygen measurement allows us to independently monitor mixture behaviour while the engine is operating.

This is particularly valuable when investigating petrol engine performance.

It can help identify conditions involving fuel delivery, mixture control or calibration that may not be obvious from diagnostic trouble codes alone.

Data Logging and Analysis

Modern engine-management systems provide considerable information about what the ECU is seeing and how it is responding.

Where supported, data logging can allow us to examine parameters such as:

Engine load
Airflow
Fuel pressure
Boost pressure
Lambda control
Ignition correction
Throttle position
Temperatures
Requested and actual values

The useful parameters vary between engine-management systems, so diagnosis is based on the particular vehicle rather than a fixed checklist.

Modified Vehicle Diagnostics

Modified vehicles introduce another level of complexity.

A problem may result from the calibration, but it can equally be caused by an incorrectly specified component, installation problem, inadequate fuel supply, boost leak, sensor limitation or incompatibility between modifications.

We therefore consider the complete engine specification rather than assuming that software is responsible.

Before ECU Remapping

A vehicle presented for tuning needs to be operating correctly before meaningful calibration work can begin.

Where our initial assessment identifies a problem, we may recommend diagnosis or repair before continuing with the remap.

This protects both the engine and the quality of the final calibration.

Specialist Services

Some performance problems require testing outside the scope of normal vehicle diagnosis.

TuningWorx also provides dedicated:

Petrol Injector Testing & Cleaning — including flow testing, spray-pattern assessment, cleaning and before/after reporting.

ECU Testing & Repair — component-level electronic diagnosis and repair for suitable control units.

These are separate specialist services rather than automatically forming part of a performance diagnostic session.

Diagnosis Based on Evidence

Good diagnosis isn't about performing every possible test.

It is about selecting the appropriate tests, interpreting the results correctly and using each result to determine the next step.

Our approach is straightforward:

Test. Measure. Understand. Then repair or calibrate.