Posts Tagged ‘diesel’

I wonder what will be the popular fuel of choice in 20 years time?

In Europe, 2011, it’s safe to say that diesel is currently most popular.  The ACEA winter report 2008 claims 70% of all new cars purchased in France, Italy and Belgium were diesel.  This trend is continuing to further favour diesel.  So what will be top in 2031 then?

Twenty years ago, 1991, diesels were not nearly as popular as they are now.  They were slow, smelly and uncouth!  The tides did start changing around this period however.  The diesel engine was now turbo charged, relatively high revving, refined, cheap to run and best of all it offered respectable performance.   Any petrol head would still be repulsed by this engine, but for the masses, this was just the thing.

Of course, low fuel consumption equates to low CO2 emissions.  Now the European governments are keen to encourage low consumption of foreign oil, this is achieved by heavily taxing fuel, justified by claims on environmental grounds.  Great, we are saving the environment, less fuel burnt means less CO2 released which means less global warming, (that’s what they want you to think anyway)!

Europe is no doubt a leader in diesel tech, but why?

In the late 80’s through to the mid 90’s when Europe was developing and manufacturing diesels, the rest of the world still loved petrol.  There are some good reasons why America didn’t share the same enthusiasm for reducing CO2 as us Europeans back in the 90s, ultimately it comes down to cost!

North America's most popular automobile of all time

It would appear that the American domestic market is driven by lazy advertisers.  Fashion trends dictate that the bigger the car the better.  The consumer is told they want low cost powerful engines, so thats what is made and thats what they buy, a chicken and egg situation.  The only thing to change that attitude will be fuel cost.

Well in days gone by, North America have had little interest in saving fuel, as they are not completely reliant upon foreign oil- they have their own domestic production.  Another big player in the auto industry, the Japanese, appear to have focussed alot of their attention on American requirements.  The Japs always tend to play it safe, not noted for innovation, they could have implemented Rudolph Diesel’s invention on a mass scale but opted out, it seems they still regard diesel as a dirty, noisy fuel and shy away from using it in their heavily crowded cities.  This leaves the  European market left hankering after frugle little cars that sip as little of the heavily taxed black gold as possible.

Lowering fuel consumption requires expensive research & development as well as increased material and manufacturing costs.  This is what holds back the rest of the world from investing.  In Europe fuel is so expensive the consumer is willing to pay more for their vehicle than an American.  However, recently opinons in the US are shifting, $4 per gallon fuel prices have been hitting the headlines for example.  Take a look at what the likes of GM and Toyota are offering.  GM has a brand image built on the American dream of large trucks, so they can’t go building small town cars, instead they are now offering hybrids as part of their lineup.  Toyota have small eco cars as their foothold and again offer hybrids.

Why do Americans generally not have diesel cars then?  The answer is simple, California!  The state of California has the strictest emissions laws in the world.  That’s right, stricter than ‘green’ Europe.

They require that the following emissions are within a strict defined limit:

  • Carbon monoxide, the highly toxic gas.
  • Hydrocarbons, a large contributor to smog air pollution and disease.
  • NOx, the nastiest of all, acid rain, smog illness and ultimately death.
  • Particulate matter, cause of asthma, cancer and found chucked out of London busses at about the height of a baby in a pram.

Now the state of California is leading the way in emissions regulations.  Diesels are essentially outlawed in California, where limits are set out in three simple classes, low emissions vehicle (LEV), ultra low emissions (ULEV) and super ultra low emissions!… (SULEV).  The majority of diesels are incapable of even meeting LEV, (note that all petrols are SULEV or better).  So in Europe we demand SULEV for our petrol vehicles and then it’s a case of one rule for petrol, another for diesel!  The European governments are essentially making special allowances for dirty diesels.  The only emissions that diesel emit less of, is the harmless gas that plants use to respire, CO2.

So, will Europe eventually come to it’s senses and outlaw diesel like California and the rest of North America?  The alternative is to ignore the problem and keep fooling people into thinking that diesel is a fine alternative to petrol.  In the background Euro 6 standards are being agreed, this will force diesels to be less efficient as they are engineered to battle against all of the emmisions equipment required to clean up their exhaust.  In times gone by, standards have been made and manufactors have responded by failing to achieve the goals, so governments simply move the goal posts!

Ultimately it is down to money, in 20 years time oil will still be lying around and it will be sourced from the same places it is found today, hence, I don’t see any shifts, unless Europe decides to actually be green and then petrol really will be the only sensible solution.

Personally I would hope to see lots more use of electricity and innovative hybridisation and down sizing for the forthcoming 20 years.

I got in my Citroen ZX typed the code into the immobiliser keypad, cranked and cranked, but no start.  Panicked slightly, at this point it was 18.30 and I was 60 miles from home.  Gave it another go and voila fired up with the most almighty plume of blue smoke.  The car then drove flawlessly at 70 mph all the way home.

Next day I came to drive it and this time it just wouldn’t start.  Due to my flawless drive home only a day earlier, I knew it wasn’t injector issues.  If it was, the failure would have left me down on power and dropping clouds of black diesel smoke.  Due to running fine once started, it can’t be the last two reasons for not starting listed below:

  •  The glow plugs are not being powered – (won’t start, runs fine once going.)
  •  The stop solenoid is not lifting. (won’t start, runs fine once going.)
  • Air in the fuel (might start and cut out or idle/run erratically)
  • Low compression, ring or valve wear. (driveability and fuel consumption both suffer if you do get it started)

Don’t worry, their is no lift pump to fail, fuel is brought to the high pressure pump via the hand primer found on top of the engine mount on cam belt side, the only failure is for it to allow air into the sytem.

First things first, these engines will very rarely start from cold without red hot glow plugs – cranking simply does not generate enough in cylinder temperature.  They are really easy to check, all you need is:

  • 5 minutes
  • An 8mm spanner / socket
  • A multimeter

1) Check you have a decent battery.  I set my multimeter up to read in the 20v range and dropped my meter probes onto the battery terminal.  Expect to see well in excess of 12volts for a healthy battery.  With the engine off mine reads 13.14v.

healthy battery

2) Now you need to measure the resistance to ground for each plug.  To get an accurate reading I suggest removing the power supply screwed to the top of each plug.  Look closely in the image below, I have removed the power from the left most glow plug.

Disconnect the power rails to all glow plugs

3) Set your multimeter up to read low resistance, I set mine up for 200 ohm or less.  Now connect the meter’s ground lead to a suitable ground, negative battery terminal is fine.  The positive should go on the top where the power rail plugs, expect a resistance of less than 1 ohm.  My number 1 glow plug measured a corrected 0.7 ohm.  The correction is -0.1 ohm as this is the resistance measured when I touch the two probes together.  If  the glow plug has failed it will read open circuit, giving the resistance of thin air (very very high!!)

glow plug resistance

4) Assuming all plugs are in good shape, you MUST check that they are being powered when you turn on the ignition.  Do not skip this step because it is most likely that a sudden no start condition is caused by a bad earth or failed relay box, pictured below.

Relay and timers for powering the glow plugs

5)  So if I think back to school a couple of formulas can be used to theorise what voltage should be read from the power rail feeding all 4 glow plugs.  Assume all plugs measure a corrected 0.7 ohms.

~ Rtot =1/( (1/0.7) x 4)

~Rtot = 0.175 ohms

We can meaure the voltage across one plug, this is essentially acting as a potential divider :

– Vin is the supply voltage acting across the whole circuit, this is battery voltage = 13.14volts in this instance.

– Rtotal is the equivalent of Rtop = 0.175 ohms.

– Rbottom is the resistance measured earlier across one of our glow plugs.  Now we want to measure Vout across that glow plug.

Vout = (0.7 / 0.175 + 0.7) x 13.14

Vout = 10.51 volts

Furthermore we can apply kirchoffs 2nd law: “The sum of the emfs in any closed loop is equivalent to the sum of the potential drops in that loop.”

Applied below, where x = potential drop.

13.14 – x = 4x

13.14 = 5x

x = 2.63

one potential drop is observed at 13.14 -2.63 = 10.51 volts.

In actual fact I measured a mere 9.43 volts across my glow plug when I turned on the igniton on during glow plug warming period:

The crucial step, power up the plugs and measure voltage on the power rail

The crucial step, power up the plugs and measure voltage on the power rail

So how much heat are these babies pumping out when they get switched on?

V = IR

I = 9.43 / 0.7

I = 13.5A per plug, giving a power of P = IV, P = 127 Watts.

Anyway I seem to have digressed.  Assuming you have power going to your rail and after approx 20 secs you see the voltage across a charged glow plug drop back to ground listen to the relay box as it clicks back.  If something is amiss, try bashing the relay box or simply unplug, clean up the contacts and plug back in.

If you absolutely must get home, I recommend spraying 1-2 seconds worth of easy start parrafin or perhaps even try some WD-40 into the intake!  This has a low flash point and will combust from cold without glow plugs, allowing diesel combustion to initiate.  Beware combustion occurs rather uncontrolled, it causes nasty knocking- potentially damaging big end bearings.  It can also cause the engine to over rev as it burns uncontrollably, that being said, use sparingly better too little than too much.

If those checks confirm glow plugs to be working, it is likely that the failure to start is caused by the stop solenoid. On my car it is used in conjunction with the immobiliser.  When the immobiliser is satisfied you have typed the correct code it sends a message to a unit hidden behind a tamper shield.  This unit, upon receiving the message, drops 12volts across the solenoid and lifts a plunger up.  This plunger is designed to stop fuel from being drawn from the fuel filter into the pump when down.  Check out the suction cup on the bottom, the action of the pump drawing fuel in, actually pulls the plunger on tighter, when in the ‘off’ position.  Here’s what it looks like when removed:

Stop plunger

The offending article

So with this stopping fuel flow, my engine was not ever gonna start!  To get to it is not elementary.  The stop solenoid is hidden under a hardened steel shroud.  There are 3 sheer bolts plus a nut and bolt at the bottom stopping any ‘would be’ thief from doing exactly what I needed to do – remove the plunger and therefore allow the engine to start.

I borrowed the services of a local handyman for the afternoon.  He got the shroud off in a couple of hours using a hammer chisel and centre punch to turn the sheer bolts.  And here it is off…

tamper shield

You can make out where the chisel went in to those bloody awkward bolts.  Don’t be afraid to disconnect the high pressure fuel lines and intake manifold to improve access for that chisel to work the bolts round ‘slowly but surely’.  I am told the most awkard of the three is the one at the bottom (blurred in this image, directly below the other two).  He used a mirror to get a visual on the bolt and hit it round with a centre punch.

With the tamper shield off, we pulled the stop solenoid out and watched to see if it popped in and out with the ignition and code.  It did but I reckon that was due to all the disturbance it had had.  I insisted we reassemble the pump with the plunger completely removed from the solenoid to see if the old girl would run.

We had to bleed the high pressure fuel lines as they had been taken out to improve access.  This was achieved, by loosening one at a time, the unions into the injector body and cranking the engine until fuel started coming out at the injector, repeat for all four.  Now I cranked for a further 3 – 4 secs whilst my assistant held the throttle open.  It fired and ran for the first time in a week!  I quickly removed the key from the ignition and of course it kept going.  Beware of doing this, I believe you remove the battery circuit from the alternator whilst it is still generating current, this is not advised and can damage stuff!

I cannot switch the car off any more with the key, I need to pull on the fuel cut off under the bonnet or simply stall the engine in gear.  I could wire a new solenoid to operate off ignition feed but where’s the fun in that?  Instead I simply tug on this rip cord when I’m finished with the car. (see pictures)

Manual engine shut off