Adventures in Auto Repair

I highly recommend that you replace your Ignition Coil, Spark Plugs, and Wires every 220,000 miles, whether they need it or not.  :-)

My $1800 1996 Sable Stationwagon began running really rough at idle.  It seemed to run OK at higher speeds, but at idle, it would almost die and would misfire bad enough that the check engine light would start flashing.  (That is the pull-over-and-stop-NOW indicator.) It would backfire when accelerating and have little power until higher speeds.  After a couple of minutes at higher speeds the light would quit flashing.

I was also having trouble with the transmission.  I suspected that the valve body was cracked.  It would hunt back and forth and slam into gear when slowing down and speeding back up at low speeds.  This got worse and worse.  Finally, it got so bad that I could no longer use overdrive -- I had to drive in D all the time.

I was also having temperature issues.  The engine didn't ever actually overheat, but the temperature would cycle up and down over several minutes.  I suspected a 'sticky' thermostat that was responding slowly.


Last weekend, I replaced the ignition coil, spark plugs, and wires.  I expected to have a LOT of trouble getting to the back three plugs and getting the plugs out of an aluminum engine.  Given the difficulty I have (age and condition) doing anything, it all went unusually easy.

However, when I started it up, it ran uniformly rough at all speeds.  I had a 50/50 chance of getting #1 & #2 wires swapped (they were hard to see and the wires were both the same length), so I swapped them.  It was MUCH worse.  OK, that wasn't it!  I checked all the connections.  Everything was plugged in good.

The guy at Advance said I might have a bad (brand new) coil.  I bought an OBD II DTC Code Reader.  It said that (only) 4 & 6 were misfiring.  The coil pack has 3 coils which fire the cylinders in pairs.  4 & 6 were NOT a pair.  That means it wasn't the coil.

I had been very careful with the front three wires.  They were very easy to get to and easy to trace.  And I noticed the odd pattern on the coil.  The back 3 were 1, 2, 3.  The front three were NOT 4, 5, 6.  So I had carefully put them in the order 4, 6, 5.

Since the Reader indicated only 2 cylinders, I dug the old coil out of the trash so I could read the numbers.  (The new one didn't have numbers.)  The order was 1, 2, 3 / 6, 5, 4.

I unplugged the easy-to-get-to wires that I was sure were right.  I carefully traced each one and put them back (correctly).  The car now runs perfectly.

Not only that!  The transmission shifts smoothly now!  The thermostat works good!  It doesn't kick in and out of overdrive going up hills!  The sun is shining and birds are singing!  Wow!

Books I am Proud to Own

As a Design Engineer, I don't use MACHINERY"S HANDBOOK frequently, but it is a vital resource. I have at least 2 copies - one for work & one for home. I frequently use the AISC STEEL CONSTRUCTION HANDBOOK for steel shapes, dimensions, and properties - I have a 1973 edition at home that falls open to all of the right pages, a newer edition at work, & a couple of older, more collectible editions.

I am particularly proud of my father's copy of AUDEL'S MACHINISTS AND TOOL MAKERS HANDY BOOK (1942) - a very comprehensive introduction to all types of machine work at a manual level that is skipped over by newer CNC oriented books.

When I was first getting started in house construction, I bought every how-to book I ran across - more because of interest than need. One that still stands out is HOW TO USE HAND AND POWER TOOLS (Popular Science, 1970) - a very good general introduction to hand tools. I got most of my helpful tips on all types of carpentry and machine work by reading straight through all of my father's 1940s POPULAR MECHANICS. But, if I had not had that resource, I would have loved SHOPWORK ON THE FARM (1945) and THE BOY MECHANIC (Popular Mechanics, 1952). THE BOY MECHANIC is actually reprints of the tips and projects from the 1940s & 1950s Popular Mechanics.

I was particularly delighted to actually need to use AUDEL'S SHEET METAL PATTERN LAYOUTS (1942). Before AutoCAD was even invented, I had two different jobs that required frequent design of sheet metal transitions from one unusual shape to another. Flat development of oblique transitions is not for the faint of heart. I still have 2 compasses that I made to hold a mechanical pencil using collars or tube clamps - a 3 foot wooden one & a 6 foot metal one. Let's see today's HVAC contractor make a 14” to 12” reducer with an 8” takeoff that reduces to 4” at a 30 degree wye!

RUUD Heat Pump Tripping on overpressure

I had a RUUD UPKA-030JAZ that had a rust leak in the accumulator that released all of the freon. It ran several days before we discovered the problem. I am sure that it overheated the oil in the compressor.


We found someone who would replace the accumulator, instead of selling us a new $4800 system. They did a very good job & it worked great until winter, when we started getting frequent tripping of the overpressure switch. This unit requires switching the reversing valve for heating. I suspected that the overheated oil had gummed up the valve and it was switching slowly, producing a momentary pressure spike. As my unit is controlled by a PLC, I had the unique opportunity to prove my hypothesis. I put a time delay so that the compressor would not start until a second after the valve shifted. The tripping ALMOST stopped.

Determining the exact pattern of the remaining tripping was much more difficult. I finally realized that it only tripped when the temperature was as hot as possible to still require heat (i.e. 50s or 60s). It did not trip AT ALL when the temperature was very cold (I allow it to run down to 30 degrees).

I determined that it only tripped during the defrost cycle, since this is the only time that I do not have control over the timing of valve and compressor. BECAUSE it did not trip at lower temperatures when defrost cycles were much more frequent, the pressure had to be just marginally too high (the pressure is higher at higher ambient temperature).

The average serviceman will not tell you this, and may not even know this.  It is worth the effort to convince them, even if it costs another service call, if it saves you $4800!

I got the serviceman who originally replaced the accumulator to 1) install Supco oil treatment which is a Teflon additive, and 2) lower the pressure slightly. I have had no further problems and expect to get many more years of service!

Zenith DTT900 HD Converter Box

Tech Tips from the In-House Engineer

As you might have already realized, most electronic devices do not really have an OFF condition, they just 'go to sleep' until something tells them to 'wake up'.  Any device with a remote control, in particular, can never be OFF.  If it was OFF, how could it respond to the remote control to turn ON?

This is not usually a problem - the power usage is minuscule and the devices are ready to respond when you want them without physically having to push a bunch of switches.  The process is usually so reliable that some manufacturers no longer include a real OFF/ON switch.  (There is no need for it.  Right?)  A real physical switch costs money and serves no purpose.  Yeah, right.  Anyone who has had to 'push the button' on their computer knows better.

The Zenith DTT900 HD Converter Box has a problem which reminds us that OFF/ON switches always have a real purpose.  At first, the problem seems to be connected to power outages or electrical storms, but now it just seems random.  About once a week, the box stops responding to the remote control.  It is still ON and still receiving whatever channel it is set on, but...  It will not change channels.  It will not change volume.  But, most importantly, IT WON'T TURN OFF!  Even pushing the 'real on/off switch' on the front of the box doesn't work because IT ISN'T A REAL SWITCH!

I'm sorry, you have probably guessed the punch line to this joke.  The only way to reset the operating system of this computer (yeah... It's a computer.) is to TURN IT OFF!  In this case, turning it off means unplugging it.  Of course, since it is installed in an entertainment center, all of the electric cords are conveniently and esthetically well-hidden and inaccessible.  In my case, near the ceiling.

After having to precariously stand on a chair (Don't try this at home?  Where else would we NEED to try this?) for the 4th or 5th time, I finally decided that problem was consistently recurrent and required fixing.  I put one of those switched extension cords in line with the HD cord so I could have a real switch where I could get to it.  A real low-tech solution for my high-tech device.  They should be readily available in any low-tech discount store, especially now since they are frequently used to switch Christmas lights.

Remember, sometimes low-tech is better.  Paper may cover Rock, but Rock can beat the crap out of Paper later.

Update 12/6/2012 It just died completely.  I wonder what will be wrong with the next one...

The In-House Engineering Department

     I don't know how anybody can survive in the world today without an resident in-house engineer.  We have purchased very few items that did not soon require repair or redesign to satisfactorily perform the function that they were sold for.  Just this weekend, I had to repair a very expensive toilet that required functional redesign of a part and machine work on a lathe because the $5.00 part was obsolete and discontinued.  The lathe work required rewiring of the light fixture over the lathe.
     On my wife's immediate to-do list, there are items that will require welding, CNC machine work, wiring, and cabinet work.  Less immediate items may require industrial design, upholstery work, and landscape grading.
     How does everyone else out there survive without an engineering department, a licensed electrician, a parts stockroom in the basement, a machine shop, a cabinet shop, and a welding shop?