Engine Trouble

Our van has had a slight shudder from time to time while the engine is running.  A few days ago it started noticeably getting worse.  Then the other day it was shaking quite a bit on the drive to work.  On the drive back home it was jerking like crazy, losing power and lurching (like when you are about to run out of gas except worse), and I was in constant fear the engine would suddenly die completely.  Incidentally the engine light came on flashing, as if I had to be told something was wrong.  I pulled over in the right lane and drove slowly with my hazard lights on the last few miles.  I actually parked at a grocery store in the last mile, let everything cool off while getting groceries, then made a dash for home and parked it.

This time it had nothing to do with the radiator, the engine was not overheating and it was holding fluid just fine.  I looked up what I could about the problems and this model of van overnight.  I called in to work the next morning and started troubleshooting.  T and I went to the neighborhood Napa auto parts store.  I picked up a new air filter, fuel cleaner (to add to the fuel and clean the engine), carburetor cleaner, and ordered six ignition coils to arrive that afternoon.  I also picked up a new toothbrush at the drug store next door.  I am used to thinking a car has one ignition coil but these mazda vans have six little coils, one for each spark plug.  (More recently my dad told me this is common now; my thinking is outdated.)  Also, they tend to go bad and create misfiring in the engine, which I was guessing was the problem, but this was a progressing problem and not something that appeared discretely. 

First I added the fuel cleaner and we put in a new air filter.  The old one was dirty but not that bad.  I have seen much worse.  Once, years ago, I parked my truck for a few days then when driving it again noticed some problems.  The air filter was more or less fine but something had built a nest in the pipe just in front of it.  It was jam packed with leaves, sticks, and fur.  It's amazing how performance will improve when you get a squirrels nest pulled out of the air intake. 

We went back to pick up the ignition coils and some new spark plugs.  However, when we returned home a work crew had come, sent by the landlord, to cut down a tree next to our house.  They needed the driveway space which prevented us from working on the van.  Then it started raining heavily, which stopped the work crew and delayed everything further.  (It was a very heavy downpour; at one point M spotted an orange traffic cone floating by down the road.)  By the time we could start working it was getting late.  However, I couldn't keep taking time off from work... 

Above T is putting in a new spark plug.  The three on the front are easy.  All you have to do is remove three bolts and a plastic shield to get to them. 

Above you can see the spark plug down in the engine (down in the hole in the center).  Above it is the individual ignition coil for that plug.  The coils are installed over the plugs to the right and left. 

Eventually T turns in.  I stay up and manage to get the intake manifold off (with a lot of bolts, hoses and cables) to access the rear three plugs. 

OK, why are engines so needlessly hard to work on?  If the engine wasn't turned sideways, all six ignition coils and spark plugs would be easy to replace, without taking so much off to get to them.  To get the manifold off, I had to fit my hand through small spaces and work by feel because there is no way to actually see the connections, which makes everything much harder than it needs to be.  Is there a car out there that is designed for people to work on? 

Also, at this point I am hoping it is simply the engine misfiring, but all kinds of strange things can happen and I may be off track in repairing it.  Once my car had an engine mount break when I was several states from home.  It made an awful noise, vibrated, and lost power.  I had to rig up a Spanish Windlass with a rope and tire iron to position the engine and remount it.  But I digress...

[To be continued...]