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Who's Your Guru?Posted 4/10/2000By Brian Manley
whether it's face-to-face, in print or online
Who's your guru? For me, and many driveability and emissions techs around Denver, it's Chris Chesney. Chris taught the 120-hour emission diagnosis course that enabled me to repair the 1985 S-10 Blazer in the next paragraph. If you live in Indiana, you may have learned the finer points of DSO interpretation from fellow Tech to Tech columnist Jim Linder. If you've read this column on a regular basis for several years, perhaps Mark Warren or Jeff Bach have taught you O2 sensor diagnosis and current probe techniques. These are the guys who help keep you and me on the technical cutting edge of sophisticated vehicle systems, which translates into professionalism, pride and profit. I recently thought about the issue of technical information after I successfully repaired the following two vehicles by using two very different information sources. "Your truck will never pass the emissions test ..." I know it sounds incredible, but the owner of a 1985 S-10 Blazer heard those very words from a local repair shop manager. My friend, Jon, approached me one afternoon about his "new" Blazer. He purchased it from his neighbor, but couldn't license it because it failed the IM-240 enhanced emissions test. Here in metro Denver, when a vehicle owner sells a car or truck, it is his or her responsibility to have the vehicle pass the emissions test. No pass, no plates. My friend proceeds to tell me that the current owner took the truck to a nearby independent repair facility for "emissions reducing" repairs. After spending hundreds of dollars for a carburetor rebuild, charcoal canister, EFE grid, choke pull-off and distributor vacuum regulator, the truck still failed, so he returned to the shop for another try. The shop tweaked the engine again, but again the vehicle failed - with higher carbon monoxide readings! After the shop poked and prodded the S-10 one more time, they finally told the customer: "Your truck will never pass the emissions test." I was floored to hear that the manager of a local shop would utter those words. The manager further claimed that the truck might still need a catalytic converter, but said, "We're not sure." I made an appointment for Jon to bring the Blazer in for diagnosis, and I systematically evaluated the vehicle using IM-240 diagnostic charts. I focused on the first of a 15-step process to funnel the emission failure diagnosis. The amazing thing about these charts is that when followed step-by-step, they never lead you down the wrong path. Weird, huh? Is the catalytic converter working? There are three ways to test it. Is the O2 sensor okay? There's a procedure to test it for response and calibration using your trusty DSO. I followed the process, which led me through the testing of the following good components and systems: engine mechanical integrity, air injection, catalytic converter, ignition system, etc. Finally, I pinpointed the cause of the excessive carbon monoxide readings: the main and power circuits in the carburetor were too rich. Re-jetting the main circuit (see Figure 1) and adjusting the power valve made the S-10 pass with a healthy reduction of emissions and a marked improvement in performance. I use this repair not so much as a technical example, but more to underscore the issue of locating - and applying - the right information at the right times. "You've gotta help me ..." Recently, a customer came to me with a 1995 Honda Accord that had an "SRS" lamp on at all times. The frantic owner, Jim, explained that he took the Accord back to the lease agent, who wanted to charge him almost $3,000 (no kidding) to repair the lamp! I took the keys and told him I'd check it out. I began by verifying the complaint. Next, while establishing the year of the Accord, I found "02/95" on the door jam and "1993" on the under-hood VECI decal. The VECI also said "2.0 liter" and "Civic" on it! Since this "Accord" had a V-6 in it, I called Jim to see if there had been any bodywork done. He confirmed that hail damage had been repaired, but swore the car had never been in an accident. I thoroughly checked all SRS-related components, grounds and connectors that may have been damaged or left loose during the body repair. Then, I went into my repair information system to collect the code extraction method and technical service bulletins (TSBs). Was I extra careful to make certain that I wasn't the idiot on the front page of tomorrow's paper who accidentally killed himself? Yes! I pulled up every word of text, complete wiring diagram and all recalls before I ever shorted the appropriate two wires together to make the SRS lamp flash. The SRS control unit flashed a code "5-1: Control unit internal fault." I also found a NHTSA recall for this make and model for "the airbag unexpectedly deploying due to a faulty SRS unit." Now I was getting somewhere! I phoned the service manager at our local Honda dealer, gave her the info, then waited for the verdict. "That V.I.N. isn't part of the campaign," she told me. I asked her if that was the final word, so she suggested I call the district office, which I did. That office referred me to a toll-free number in California at national headquarters, where I received the same answer. They did tell me that was the final answer. I didn't like those answers, and I didn't want to tell my customer that he'd have to buy a $450 SRS unit, so I decided to compose my first "post to the group" on the International Automotive Technician's Network (iATN). I submitted my post on a Tuesday afternoon and the next morning I had seven responses, four of which were from Honda techs. In essence, I received all of the pertinent technical information that I needed to complete one more test, then give my customer an informed answer. Ultimately our Honda dealer split the cost of the SRS unit with my customer and installed it at no charge. My customer received the factory-updated module, saved $2,500, and gushed with appreciation. I earned an appropriate diagnostic fee and learned the power of collective knowledge! You Don't Know What You Don't Know You and I are experienced techs with different backgrounds, specialties and comfort levels. How do you fill in your information "gaps?" I know, you read this and other industry magazines (this one, of course, being the best), attend training clinics, network with colleagues, etc. But what if you work in an independent repair shop, as I always have, that tackles virtually everything on wheels? Nobody knows it all, certainly not me. But if you're passionate about driveability or emissions or electrical diagnosis, as I am, or just can't sleep until you figure out that elusive intermittent condition, like I do on occasion, then I have a strong recommendation that may help keep your hair from falling out, as mine is. Get online, establish your own e-mail account, then become a member of iATN. (You can connect to the iATN site through the ASA Web site at http://www.asashop.org. Go to the "aftermarket" section of the "Related Links" area.) Sign up and become a part of a collective mind with more than 25,000 members worldwide, all with different backgrounds, specialties and comfort levels. Warning: When you submit your specialty areas, you will begin receiving e-mails each day asking for insight on all "posts to the group" that fall into those categories. If you're the best transmission tech in town, and that is your major specialty area, then list that as your area of expertise. When you peruse the list of e-mails each day (don't worry, they will come each day), respond to the ones that you can help. If you do this diligently every day or so, then you earn the right to post a message to the group when you need assistance on a tough repair. Don't stop there. Look at the forums each day to stay abreast of the latest industry topics that concern us all. If you do this once each day, guess what? That's daily wisdom gleaned from gurus all across the country! By the time you read this, I'll have taken another class from my guru on advanced OBD-II diagnostics. But each day, I'll log onto iATN to help fill in my information "gaps."
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