You will be redirected to the script in

seconds
   
  Tech to Tech

Scope's Pattern Helps Sell Diagnosis

Posted 7/15/2005
By Jeff Bach

Visual format helps people like 'Old Albert' understand what's going on

Prejudging people is not necessarily considered a good thing by most folks. But I find sizing up my prospects to be, at times, an interesting and entertaining hobby - especially when one comes along who is obviously a "character."

Sometimes I'm way off base but more times than not, I'm pretty close to being right.

Sometimes their bumper stickers give them away. And I have a feeling I'm not the only one who can guess at least three of the radio stations programmed on customers' radios just by looking at the vehicles' décor.

Over the years, I've had to reprogram a lot of radios. It helps when you're getting ready to do any type of electrical work that requires disconnecting the battery to write down the stations programmed, and later, program them back like they were. I even check now and write down the station that's playing.

Sometimes the husband is dropping off and picking up the car and his favorite station may not be programmed on the wife's radio. I have found that for a lot of people (probably more than you would guess) it's a big deal if their stations are all screwed up and the clock is wrong. For some people this can shake up their whole world.

And then there's Albert.

Albert pulled up behind a bay the other day unannounced. I'm sure he was hoping to be next in line to get his car fixed while he waited. Albert is probably fast approaching 70 and is a big country fellow wearing new work boots, bib overalls, and a Farm Seed Co. cap. He's sportin' a fresh chaw in one cheek and wearing about a carat and a half in his earlobe. Now here's a guy with an opinion.

Albert's driving a '93 Caddy Deville with a 4.9. He's got a miss in his engine he thinks is caused by bad injectors. He's got nearly 130,000 miles on her, and she's never had the injectors changed.

When I hear people talk about their car's gender with this sense of pride it makes me think about asking them the obvious question, "What's her name?" But I can feel myself fighting back a grin because I just know it wouldn't go over good with this guy. I wonder, though, if I shouldn't start putting that information on file and start sending personalized maintenance reminders to some of these customers. "Old girl," "Milly," "Bessy" and "Betsy" are a few of the actual names I've heard people call their vehicles. (I'm sure they come from a guide to names deemed appropriate to call your mule or workhorse!)

Figure 1

Figure 2

Figure 3

Back to the car.

"Well, these things are known for injector trouble," I said. "I can throw you a set of injectors in there for about $1,400 or $1,500 if you like or we can do a little testing and make sure she's really in dire need." Now I know this guy has been talking to somebody. I get the idea his car's got the same feel as his buddy's Caddy that got some new injectors, which fixed its problem. I'm bettin' he's not ready to part with that kind of cash just to give the old gal a fresh set.

Spat! He spits a brown puddle on the concrete right next to a small spot that is oil stained. "You're supposed to be the expert," he said. "I was hopin' you'd hang some of that high-tech equipment you got on 'er and tell me what's ailing 'er."

"Well, the scope I need is tied up on another car right now but if you can bring her back about 2 tomorrow afternoon, we'll put it to her." Albert agrees and shows up early at 1:30 p.m. the next day. I drop his (her) hush panel and hook the current probe adapter to the two injector fuses, expecting to get a high spike or three and a parade pattern that looks picture perfect (Figure 1).

Well now, that casts a different light on the subject. I explain to Albert that these injectors fail because of low resistance normally and none of his injectors show any sign of that. I've yet to see one cause the dead miss we're after by sticking but I blew up the pattern and watched the seagull in the charge ramp for signs of sticking and saw none. I went in to his onboard computer diagnostic program and then to the injector override feature and cancelled the injectors one at a time, finally deciding that the No. 4 cylinder was the dead one. I put the current probe around the ignition feed circuit to the distributor, which is easily accessed down by the brake lines in front of the booster along the left frame rail.

Figure 2 shows the normal primary pattern, and the one spike that drops below the zero line is our bad wire cylinder.

I changed the scope settings to blow up the bad cylinder pattern and triggered on the current below the ground (Figure 3).

I got the picture shown in Figure 3 and explained its significance to Albert who immediately broke into a satisfied-looking grin as though he'd just won a bet with someone. He asked, "So they ain't nothing wrong with them injectors?" "Nothing that a tuneup wouldn't fix," I replied. I estimated a full tuneup for him. He agreed and brought it back the next day. While replacing the plug wires I could see that No. 4 was lying on the exhaust manifold and had burned nearly into it.

Once the work was completed, he was glad to have the "old gal" back. He was happy and couldn't thank us enough.

I suspect Albert has a lot more going on than he's letting on. I just got the feeling that there's a whole story here that's left untold.

It's still amazes me the difference I see in the way people receive diagnostic news when I tell them of their cars' woes while pointing out their problem in a visual format to which they can relate. It's just as effective as that SUN 2001 diagnostic computer was in the '70s that I have sitting in my barn.

Jeff Bach


share your thoughts...

RATE THIS ARTICLE

What do you think of this article? Your input will help AutoInc. develop additional articles on this subject. Share your thoughts!

Your name

Your e-mail address

  

MOST ACCESSED ARTICLES

MOST E-MAILED ARTICLES