2014-10-28

Car Diagnosis: it won't start

After an online discussion elsewhere late last week, I felt a need to visit a the subject of car repair.

Or diagnosis.

Some time ago, a distant relative posted a question on FaceBook. The question was something like, "My car won't start. Any advice before I call to have it towed to the shop?"

This question ought to be easy to answer.

There are three very big domains that the problem could be in. And "the car won't start" could mean any of these.
  1. Turn the key, and nothing happens
  2. Turn the key, and hear the starter motor turn the engine over...but the engine doesn't 'catch' and start running on its own
  3. Turn the key, and the engine starts running, but dies almost immediately.
Each of these point to the problem, but don't give definite answers.
(I'm assuming, while going through this list, that you have a choice between doing something yourself, a friend whose done some car repair, or a tow-truck trip to a repair shop.)
  1. Problem: key turned to "START", but no response from starter motor.
    1. Can you test the headlights?
      Turn the key to "RUN", but not to "START".
      Find the switch for headlights, and try to turn them on.
      1. If the lights are dim, or not visible at all, then the problem is likely a low battery
        You might be able to start the car by the method of jump-starting.
        To do this, you need jumper cables and another vehicle. 
      2. A helpful guide for diagnosis, and attempting a jumpstart, is here.
        However, if you can't confidently identify the "+" and "-" terminals on both batteries, it's not a good idea to guess.
    2. If the lights are bright, the problem is likely the starter motor.
      1. Fixing a starter motor typically involves un-bolting it from the underside of the engine, and putting a new one in.
      2. If you don't feel confident in finding the motor, or successfully un-bolting it, you might be able to find someone to help you.
        Or call a tow truck to have the vehicle delivered to a repair shop.
  2. Problem: key turned to "START", engine turns over but doesn't catch.
    1. It could be that the ignition system isn't delivering a spark where it is needed, when it is needed.
      Do you feel confident you can identify a spark plug and its associated wire?
      If not, find someone who can help you...or you'll have to find a repair shop that can handle it.
      1. Assuming you have identified one of the spark plugs, and own (or are willing to spend money on) a spark-tester:
        Unplug the wire from the spark plug, plug the wire into the tester, and use the tester to discover if if you have spark. 
      2. Assuming you have the confidence and tools to un-screw the spark plug from the engine:
        Unplug the wire, un-screw the spark plug, and put the plug back into the wire.
        Hold the wire-boot, such that the side of the spark plug is touching the engine-block.
        Have someone else try to start the engine.
        1. If you see a spark jumping across the gap when the engine turns, then the ignition system is delivering a spark when appropriate.
          You should probably go to 2.B. below.
        2. If you don't see a spark, then you need to fix something in the ignition.
          You could end up replacing spark plugs, wires, ignition control modules, distributor caps, crank-position sensors...
          Or you could end up asking a talented friend, or a repair shop, to check/replace these things for you.
    2. It could be that the fuel system is not delivering fuel to the engine.
      1. If you had the spark plug out while testing in 2.A.ii, you ought to be able to tell whether any gasoline was delivered to the engine. You should be able to smell gasoline inside the cylinder.
      2. Another test: most modern cars use a fuel pump. This pump turns on automatically when the ignition goes from "OFF" to "RUN". 
        1. If you can hear a slight hum from the rear of the car after turning the ignition from "OFF" to "RUN", then the fuel pump is probably providing fuel.
          You might have a leaky fuel line, or a blockage somewhere between the fuel pump and the point where fuel is injected into the engine.
          This is probably something to take to a repair shop. 
        2. If you cannot hear the hum of the fuel pump starting...then you probably also want to take the vehicle to a repair shop.
          Replacing a fuel pump usually involves removing a fuel tank and opening it up. Easier than replacing all the fuel lines between the tank and the engine. 
    3. It could be that the engine has fuel and spark, but no air providing oxygen.
      This is somewhat rare. 
      1. Many modern engines have an airflow sensor that is used to control fuel injection and ignition.
        Replacement parts can be purchased. In a pinch, it might be possible to clean the sensor.
        There is little risk in getting help from a knowledgeable friend in this. There is little risk in taking this to a repair shop, but you'll end up paying a somewhat-high hourly rate for replacing a part that is easy to replace.
      2. If the problem is a dirty air filter, it is possible to attempt to start the engine without the filter.
        However, it is very foolish to run the engine for more than a few seconds without the air filter. The filter is designed to keep dirt and grit out of the engine. If too much dirt or grit gets into the interior of the engine, it can lead to scratches on important surfaces (like cylinder walls) inside the engine. These surfaces are supposed to be smooth. Scratches can introduce all kinds of expensive-to-repair problems.
        Happily, air filters are usually easy to replace, even for automotive-repair novices.
        They are also usually very affordable, and usually on-the-shelf at the car-parts store. Make sure you get the correct filter. 
      3. Very few cars use carburetors these days. If your car does use one, it probably needs to be cleaned.
        If you're deciding between a knowledgeable friend and a repair shop, this one is a toss-up. Either method is good.
      4. If the car uses some sort of fuel-injector to mix fuel and air, then you likely need to diagnose/replace the part.
        In this one, a knowledgeable friend can help, but a repair shop might be better.
  3. Problem: the starter motor turns the engine, and the engine sputters and dies.
    This falls into the same diagnostic pattern as Problem 2...Spark, Fuel, Air.
    Except this time, you have enough to get the engine running for a moment, but not enough to keep it running.
    1. If you are able to test spark-plugs, test each of the spark plugs on the engine.
      It's generally a good idea to pull out only one plug and wire out at a time. The pattern for connecting wires to plugs may not be intuitive, easy-to-remember, or obvious. If you unplug them all, and plug them back in the wrong order, you're worse off than when you started.
      1. Once you figure out which spark plug(s) are not firing, you probably have a very simple repair. Usually, it is specific wires or specific plug(s) that are bad and need to be replaced. 
      2. However, as long as you're replacing some plugs (or wires), it might be good to replace them all.
      This kind of work is easy to do yourself, if you have the ability (and tools) to pull a spark plug. However, not all combinations of spark-plugs-and-wires will be available at the car-parts store.
      A talented friend or a repair shop can do this repair also.
    2. If the problem is with lack of fuel, then either 
      1. The fuel pump can't supply enough pressure, because the pump is wearing out.
      2. The fuel pump can't supply enough pressure, because a leak in the fuel-line between pump and engine
      3. The fuel pump can't supply enough pressure because a fuel line is partially clogged.
        All three of these generate the same advice as 2.B. above. You'll probably want to take the problem to a repair shop.
      4. It's also possible that a fuel injector has failed, or is clogged.
        If clogged: depending on how serious the clog is, and how soon the engine dies, you might be able to fix this with a fuel-injector-cleaner, purchased as the car-parts store.
        However, if the injector has failed, it needs to be replaced. This is probably best done at a repair shop.
    3. If the problem is with air-supply, then either
      1. An air sensor is malfunctioning. (same advice as in 2.C.i above)
      2. The air filter is clogged, and needs to be replaced. (same advice as in 2.C.ii. above)
      3. If a carburetor is present, it may have a partial clog that needs to be cleaned out. (same advice as in 2.C.iii above)
      4. Otherwise, an injector may need to be cleaned/replaced. (same advice as in 2.C.iv above.)
Most car-won't-start problems can be diagnosed with this process. However, some don't quite fit in that list.

I have, in my car-ownership career, met a problem that looked like a bad starter motor (1.B.) Except when I took out the starter motor and took it to the car-parts store for a test, the starter motor worked fine.

After several hours of study and puzzlement, I figured out that the electrical relays that were supposed to trigger the starter motor weren't working. The relay replacement was cheap and easy, once I knew what the problem was.

2014-09-22

Two kinds of motorcycle riders

There's a saying among people who ride motorcycles.

Roughly, there are two sets of riders. Set 1 contains riders who have fallen off their motorcycle while riding. Set 2 contains those who have not fallen off their motorcycle...yet.

Up until this past week, I was in Set 2.

On Friday, while beginning a broad curve entering the parking lot at work, I saw what looked like an obstacle in that broad, sweeping path. I quickly tried to cut the curve much tighter...and felt the motorcycle fall over underneath me, while I landed on my chest and skidded to a stop.

A moment later, I stood up and dusted myself off.

My protective gear for that ride (helmet, jacket, gloves) kept me from serious harm. Though my knee somehow got skinned (without my pants tearing). And my chin felt bruised from the way it impacted the inside of my helmet.

Though I got a little ribbing from the guys in the office...

The motorcycle is a little worse for the wear. She's missing the big plexi-glass fairing that used to be on front, and missing one of the mirrors on the handlebar.

All told, I'm happy to have survived the event. Though I'd be a little happier if I could have done so without landing face-first on the pavement.

2014-08-06

Fun with statistics

Yesterday, I got a little involved in the comment-thread of this article by Megan McArdle.

At one point, another commenter posted something about the number of workplace deaths in the United States. Something like "4628 workers were killed on the job in 2012." *

This number might be valid, or might not.

However, I immediately noticed something odd. I remember that a much-higher number of people die in vehicle-related accidents on a yearly basis.

So, basically, I asked this question: since ~35000 Americans die in automobile collisions per year, is it more dangerous to drive to a job, or to be on the job? **

------------------------------------------------------
* This statement is a comment about a number, not an argument. But it was offered as if it was an argument.
I think I'm seeing these unspoken assertions:
1. A large number of people died on-the-job in the United States
2. Workers need some form of protection from this
3. Unions are both necessary and sufficient for this protection

This chain of reasoning has several holes.

About point 1: The data provided is only for the year 2012. No data was provided about how this number related to Unions, or to State/Federal regulations about workplace safety. No data was provided about how this number has changed as the level of Unionization has changed over the past three or four decades. No data was provided about how this number has changed relative to man-hours-of-employment over the past few decades.

Point 2 is hard to quibble with, but proposals coming from Point 2 depend heavily on the data that went into Point 1.

About Point 3: this also depends on data. There are many ways to reduce workplace fatalities in the U.S., and the Unions and U.S. Dept. of Labor have been trying to do that for many decades. Perhaps some data about these efforts, and how these efforts interact with business efficiency, corporate practice, and the change of Union membership in the United States, should be brought into the discussion.

** My source on this is the Fatal Injury Statistics website, which is provided by the U.S. Dept. of Health Center for Disease Control and Prevention.
The numbers are between 35000 and 36000 per year for most years since 2009.
Oddly, the number dropped from ~45000 per year in 2007 to ~35000 per year in 2008.
The per-capita rate had shrunk in most years from the 1980s to 2007, but the static value had remained near ~45000/year during most of those year. But there was a big drop in 2008, and it has remained since then.

2014-08-04

Vehicle death

Another blogger had to get rid of a vehicle recently.

In his case, he had a Jeep which developed engine trouble...of the kind that rapidly turned into too-expensive-to-be-worth-fixing.

He ran into one of the long-term-ownership problems in the automotive world. Almost all vehicles are now made to have near-zero maintenance trouble. For something like 8 to 10 years.

But most vehicles have design problems that will begin making ownership expensive. Sometimes these problems are foreseeable, sometimes not. Sometimes they arrive shortly after year number 8. Sometimes they wait until 12+ years.

Sometimes they are avoidable. My current vehicle, a Subaru, suffers from potentially-catastrophic failures to the timing belt. These tend to come somewhere between 100000-miles and 110000-miles. However, the belt can be replaced before this becomes a problem.

Other times, these problems are not avoidable. An earlier car I owned (early-90s Taurus) had transmission trouble. This model of car, though extremely popular, regularly suffered transmission failure at ~80000 miles.

Robb's Jeep had a different category of problem, but one with similar results. The engine failed, and in a way similar to most other Jeeps of that model-and-age combination. Thus, most junk yards have such vehicles, but few have replacement engines handy. (Robb noticed that the salvage yard had 10 such Jeeps, 8 of them with the same engine failure. And two engines that did not have such a failure, but required expensive rebuilds anyway.)

And in his case (as with my old Taurus), the cost of repair is more than the resale value of a good, working vehicle of that type.

One of the frustrations of buying used cars is that such things can creep up on the unwary buyer. Yet one of the frustrations of buying a car new is that after you keep it for a decade, you want it for another five years...and problems like this can also sneak up on you.

Like Robb said, it's a First World problem.

2014-08-01

Going, going...gone.

Sold a vehicle this week.

The old Jeep had sat for months. One relative had told me they wanted it...then they backed out. Another expressed interest, then they also backed out.

In the meantime, the vehicle had become a little cranky. I didn't establish a habit of running it one day a week. So when I tried to start it, I seemed to find trouble 50% of the time.

Finally got it back into predictably-running condition, and put it on Craig's List. But taking it for test drives reminded me of the parts I enjoyed about the Jeep.

But I was also reminded that I don't like keeping a vehicle I'm not going to use. And I wanted to switch to a stick-shift.

So when the one potential buyer came to look at the Jeep, I was happy to get an offer from them.

I was also happy that they paid cash, rather than cutting a check. We signed the title, shook hands, and they drove away.

Now that the Jeep is gone, I miss her. But I don't miss the cost of filling it with fuel.

And I enjoy a car that gives all-wheel drive and direct control of the shifting.

2014-07-31

Work

I feel as if I spent the last week in a deep, dark hole. (Blog-post wise.)

At the office, I discovered that somehow a large amount of merde had been fed into the ventilateur. (Pardon my French.) The result has been long nights, long waits for code to compile, tests of software, comparisons of day-by-day builds, careful combing of log-files, and endless worries about whether our customer will accept the upcoming release.

The bad thing about this is that the customer expects hardware-plus-software to arrive at their factory in final form...near the end of September. And we're working on the Bug-Fix releases, which (theoretically) should have already had most problems ironed out.

Except not all the problems have been ironed out, as we're discovering. And the remaining problems are hard-to-diagnose. Which makes life really hard on everyone in the team.

2014-07-24

Weather

Riding a motorcycle gave me a slightly different view the weather and local climate.

I have to pay much more attention to rain forecasts. Because a two-wheeled machine can have traction and stability problems on wet pavement. And because the motorcycle has no roof.

Temperatures also have a different meaning when I'm rolling at 45 miles per hour. (Or 65 mph...) A day that goes from 60° F to 80° F means that I need the windbreaker jacket for the morning ride, and the vented jacket for the evening ride. However, a day that goes from 70° F to 90° F doesn't change the ride as much.

On many nights, I can feel the change in humidity when I descend into a river valley. Sometimes it's warm and moist; sometimes it's cool and clammy.

Last night, the temperature dropped from upper-70s to lower-60s. Which means that today, I may drive my car instead of ride my motorcycle.

This summer has been cool, which has decreased my desire to ride as much as possible. But I also have a car that is better than the car I had last year. So maybe I enjoy driving a little more, also.