Hot miss, cold miss, hard start, no start. There are numerous ways an automotive or light truck ignition system can compromise driveability, but for profitable shops, the shortest time to a successful repair often boils down to a single factor: diagnostics. From pocket multimeters to full size engine analyzers, there are numerous ways to skin that cat, but only a few that will do it with speed and efficiency. And today, there’s more to suspect, and more to inspect than ever.
“Troubleshooting secondary ignition patterns can be a valuable tool when diagnosing vehicles. In the past, looking at the pattern in a basic form would allow you top determine if you had an ignition problem and if so, what the probable cause was. That was when all cars had many points where a failure could occur, such as coil, cap, rotor, wires and plugs. With the move toward coil on plug technology, the possibly of component failure is reduced because the number of components are reduced. Direct ignition systems eliminated cap and rotor from the vehicle, and coil on plug has eliminated secondary wires. The basic diagnostic of the secondary ignition is do we have spark, and if not, is it the coil or plug. This has opened the door to basic go, no go testing products to determine secondary ignition troubleshooting.”
Toushan believes that ignition issues can reveal much more about engine internals: “Don’t underestimate the value of secondary ignition troubleshooting for finding other problems. A thorough understanding of reading ignition patterns allows the technician to see not only the secondary ignition, but also what is happening during the combustion process. Waste spark systems also allows the tech to look at the exhaust for diagnostics. Things like leanrich conditions or combustion turbulence can help the technician find minute vacuum leaks, injector spray or carbon build-up. Looking at all the patterns at once can allow you to see inconsistencies as well as individual cylinder performance testing. And that’s just the beginning; experience can open the door to many neat methods to find fine or intermittent problems. Equipment companies that are serious about the diagnostic business are producing coil on plug adapters because an ignition pattern tells a tale of more than just coils and plugs.”
One of the original benefits of traditional ‘scope type analyzers was the ability of an experienced technician to extract a great deal of information from a single trace. Ignition patterns can still be used to advantage by a competent tech, according to John Mills, regional technical trainer with SPX Canada: “For the technician who is well-trained and has experience, looking at ignition patterns gives you a window into what is happening not only in the ignition system itself, but also in what I call the “cylinder circuit”. Basically a cylinder circuit is anything relating to that particular cylinder, which would include sealing, pistons, rings, valves, compression, fuel delivery and ignition. Basically, an ignition scope will give you a picture of what is happening within that cylinder circuit. The task for the technician is to figure out whether the abnormal picture is the result of a mechanical situation, fuel situation or an ignition situation.”
John Mills’ preface about training and experience underscores the biggest weakness in diagnostics in most Canadian shops: knowledge. Don Russell, vice president, marketing for Ferret Instruments relates knowledge to one side of a three-sided triangle: “If you draw a triangle and you put information on one leg, knowledge on the other leg and equipment on the third, any one of those legs can be of any length or any significance. You can give a tech a voltmeter and he can pretty much troubleshoot no-start cars providing that he has extensive knowledge on how the systems operate. The guy who doesn’t have a lot of knowledge or a lot of information at his fingertips is going to have to rely on a larger amount of equipment. As far as selecting the right tool, I would take that further and ask, does he have the appropriate education and knowledge to support the tools that he has, or does he need more tools? I always say that a technician doing any sort of engine diagnostics needs a scan tool, a lab scope, an engine analyzer, a good multimeter and an information source as a bare minimum. Now which flavour of each one of those things is dependent upon your own knowledge base. The less you know, the more sophistication you pay for, so the analyzer helps you more.”
One of everything is an ideal way to go, but smaller shops must make hard choices about diagnostic equipment. Is a handheld enough, or do I need a full size analyzer too? That debate has been ongoing for the twenty or so years since the first handhelds appeared on the market. The “correct” choice depends largely on what the business is trying to achieve with diagnostics. Three tune-ups or no-starts a week simply won’t justify a full-scale machine, and most shop owners have seen operations where expensive equipment gathers dust in a corner. Conversely, businesses that wish to target engine driveability either as a shop specialty or with a dedicated bay, can drive traffic by using the hard copy output and power of the full analyzer to create a high value image with consumers. The tradeoffs between speed, cost, and the necessary bay traffic to make it all work isn’t an easy calculation, especially when financing and obsolescence is an issue.
“As an ex-shop owner, I know exactly where they are coming from. You are almost gun-shy to make a purchase because of the obsolescence issue,” says Kirk MacKenzie, Product Specialist for Snap-On Diagnostics. Mackenzie specializes in handheld equipment and recommends a modest investment for shops starting serious diagnostic services: “The entry level for the large percentage of shops is being held by handheld diagnostics. The ballpark figure would be $7500 to $10,000; that’s covering scan tool, ignition diagnostics and fuel pressure diagnostics.” Any investment of that size needs a calculated bay traffic to accelerate return on investment, and in diagnostics, it’s happening, says MacKenzie. “Five years ago a scanner would sit on the shelf and be pulled out occasionally; it would go back into the case and be pulled out three times a week. Today it never goes back in the case. It’s out all day long vehicle to vehicle, being used on everything from ABS to engine to transmission.”
Relative to performance, handheld pricing has dropped steadily over the years and with that drop has come a steady shift of diagnostic equipment away from the shop purchase and toward the individual technician’s toolbox. A driving force for the change has been the portability of the equipment, allowing many bays to share a unit. In a flat rate shop, where a technician loses money waiting for a tool, ownership of basic equipment is a sound financial decision. The trend toward technician-owned diagnostics is following a mature individual market south of the border, according to MacKenzie: “For eight years or more that has been the norm down there. It is now evolving that way here. But it’s evolved for a different reason; they’ve been forced into it. It’s a flat rate guy that says, “I can justify the expense”. They are almost forced into it, in order to fix cars quickly and productively. So it becomes a timesaver tool like any other.”
Regardless of the level of a shop’s diagnostic technology, ignition systems are a good starting point for profitable driveability and no-start service. Training and experience are irreplaceable, and should be factors in any equipment purchase, large or small. As Tim Toushan says, “An engine analyzer will not fix a car. They’re tools that save you time, make you disciplined and take you through a consistent routine for testing. Don’t ever take your eye off the value of the technician and the on-going training that he needs.” SSGM