Tech Tip: Nissan Optical Distributor Test
Many Nissan vehicles have a power transistor controlling the coil (or igniter). The power transistor is a separate unit on optical distributors. It allows the signal sent from the ECU (low current) to activate the primary circuit in the ignition coil (higher current). This induces high voltage in the secondary windings of the coil, providing spark to the distributor cap and plugs. If this transistor is faulty, the necessary spark will not result.
Tech Tip: Intermittent No-Start on Ford 5.4L V8 Truck Engine
When it won’t start, there is no communication with the Powertrain Control Module (PCM). The theft light is flashing rapidly with codes U1147 and U1262 in the Hybrid Electronic Cluster (HEC). Also, the odometer just shows dashes with the key on instead of the actual mileage.
Tech Feature: Valve Timing Terror Tales
While a lot has been written about timing belt replacement intervals, not a lot has been written about diagnosing timing belt and valve timing-related driveability complaints. In this article, Gary Goms reports that he is beginning to see more driveability problems caused by faulty valve timing.
Tech Feature: Detecting Misfires in OBD II Engines
With OBD II, there’s no missing misfires. Most engine control systems with OBD II monitor the speed of the crankshaft between cylinder firings to detect misfires. The powertrain control module (PCM) notes the relative position of the crankshaft via the crankshaft position sensor (CKP) each time a trigger pulse is sent to the ignition system.
Ignition Sensor Diagnostics: Variable-Reluctor, Hall Effect and Magneto-Resistive Sensors
Although ignition failures are relatively common, they’re not the easiest problem to diagnose. To help you get started on what I call a “systems approach” to ignition diagnostics, this article is intended to provide an overview of how to identify ignition system configurations, identify three different types of ignition sensors and understand several basic sensor-operating strategies.
Toyota Tech Tip: MIL On, Misfire DTCs Set on 1MZ-FE Engines
Some vehicles equipped with 1MZ-FE (V6) engines without VVTi may exhibit a rough idle and/or an MIL-on condition with a diagnostic trouble code or codes for misfire caused by an improperly operating ignition coil assembly. Production changes have been implemented to prevent this condition from occurring.
Tech Tip: Subaru Ignition Coil and High-Tension Cables
When diagnosing a misfire code(s) P0301, P0302 P0303 and/or P0304, there is the possibility that the ignition coil and/or high-tension cables could be the cause.
Tech Feature: Getting The Most Data From Your Scan Tool
It’s more than likely that many technicians use their scan tools as diagnostic trouble code (DTC) readers rather than as the analytical and testing tools that they really are.
Tech Feature: Cooler ‘Heads’ Prevail – Pouring Over GM’s LT1 Engine and Reverse-Flow Technology
The LT1 engine was used in a variety of General Motors models, including 1992-’96 Corvette (Y-body), 1993-’97 Camaro and Firebird (F-body), and 1994-’96 Chevy Caprice and Impala (B-body), Buick Roadmaster and Cadillac Fleetwood (D-body).
Tech Tip: Servicing a Malfunctioning Automotive Ignition Switch
The automotive ignition switch, formerly a straightforward device used to connect battery voltage to various circuits and prevent theft of the vehicle, has recently been switched up.
Tech Feature: Mazda Driveability Diagnostics and Check Engine Light Complaints
From a torn air intake hose to ignition system concerns, Bob Dowie tackles driveability issues as well as some of the more common ailments that will bring Mazda vehicles into your bays with a check engine lamp complaint.
Tech Feature: What’s New in Spark Plug & Ignition Cable Technology
Ignition systems have changed a great deal in recent years, with coil-on-plug (COP) ignition systems being the most common setup on many late-model engines. Car makers like COP ignition systems for a variety of reasons. The main one is that mounting a small ignition coil over each spark plug gets rid of the troublesome spark plug wires. Plug wires are vulnerable to heat and vibration damage, and can become a source of ignition misfire if they become wet.