Top 10 Most Popular Articles
September 26, 2010
Automotive Video brings you the Top 10 Most Read Articles on Scope It Out! The most popular articles include everything from J2534 to Duramax, waveforms to labscopes, tpms to fuel injectors, as well as parasitic battery drains. Check out what other readers are into and post your comments and questions.
Keep On Truckin
GM truck tire size changes and calibrations. As American car and truck enthusiasts mourn the crazy economic conditions that have caused icons like Pontiac and GMC to go into the annuls of history, I suspect we will ‘Keep on truckin’ as the saying goes and continue our love affair with cars and trucks and with that continuation will be the business of repairs and customization for those reading this.
Exploring the Duramax
Diesel engines all fire their mix using high compression, and they need precisely controlled fuel delivery, both in regard to timing and volume. Diesels typically spin slower than gas-burners, but the torque that diesel engines are capable of producing is practically legendary. That’s one reason heavy-duty truck manufacturers went diesel on their heaviest platforms so many years ago. So, why does a diesel produce more torque?
Parasitic Battery Drains
Para What? It’s amazing how many IATN posts I see with good techs struggling in the area of parasitic battery drains. How much is too much? How to test? I guess I shouldn’t be amazed. I literally grew up in the family auto electric shop and this kind of thing was our bread and butter. For the rest of the shops out there who have to be experts in everything from the turn signals to the transmission, it can be a bit confusing. So what is a parasitic battery drain?
New Twist on an Old Story: GMs Variable Valve Timing
Powertrain engineers continue to extract more power from and reduce emissions on conventional internal combustion engines. When both intake and exhaust camshafts get involved, GM’s variable valve timing system meets both goals. Remember the good old days? Chubby Checker was singing “The Twist” and we had cheap gas and fast cars. I was a young mechanic a decade later, in the ’70s, and I can still re- call hearing my first GM muscle car sporting a performance camshaft loping into my bay. It was the sound of power, and I knew that this engine wasn’t going to the run like the rest!
Introduction to J2534 and Flash Reprogramming
The days of diagnosing and repairing automobiles without a laptop beside you are quickly fading. Newer vehicles include a large number of onboard computers that are each dedicated to performing specific tasks. Common onboard computers in newer vehicle include the Engine Control Module (ECM), Transmission Control Module (TCM), Fuel Injection Control Module (FICM), Anti-lock Brake System (ABS), Body Control Module (BCM) and numerous other control modules to manage every electronic system from power door locks to crash data.
Anatomy of a Waveform
I remember a phrase I heard recently stating that, “necessity is the mother of invention.” As I look at the modern-day digital storage oscilloscopes, I also look back on the history of diagnostics on the coil-fired internal combustion engine and I can’t help but recall all of the great diagnostic information the old Sun scopes gave us in the “good old days.” I mean, after all, we could look at a single cylinder secondary waveform, a parade pattern or a raster pattern under dynamic conditions and make sound diagnostic decisions on air/fuel ratio problems, compression problems and, of course, ignition system electrical problems in both the primary and the secondary ignition system.
Common Rail Invasion
Get Ready for a New Wave in Light-Duty Truck Diesels for the 21st Century. Rudolph Diesel’s 1895 engine design used compressed air to blow coal dust into his combustion chambers, and the fact that his design used cheaper fuel and not as much of it caused diesels to rapidly become the only real choice for stationary or ship engines.
Testing Injector Flow With a Scope
Fuel flow and injector faults can result in drivability problems. Some OEM scan tools, as well as some high end aftermarket tools, allow you to perform power balance and/or injector balance tests on those OEs that support such a test. Injector balance can also be done using a tool that fires the injectors individually while you measure the drop with your fuel pressure tester, but this can be a time consuming task. There is another way to check this flow, and it uses a DSO and a special pressure transducer.
Check Your Air, Mister? Servicing TPMS Systems
As a once-familiar gas jockey greeting passes into history, now-mandatory TPMSs have made it easier for drivers to monitor tire pressures. Servicing these systems is somewhat more complicated than operating a tire pressure gauge.
Automotive Labscope Specifications
The problem most automotive technicians face when trying to select an appropriate labscope is reading and understanding labscope specifications and then matching those specifications to the test requirements. Our objective is to explain bandwidth and sampling specs as they apply to automotive testing. Once you’ve read the labscope spec data and compared that data to your requirements you can make a better decision.
