Engine Stop-Start Systems

Starting and stoppig is merely running the starter motor after a certain number of seconds after the brake is engaged and the ignition key is still in the Start position.

Engine Stop-Start Systems Explained – Tech. Dept. – Car and Driver.

Recently our fully paid 2003 Hyundai Trajet MPV (its a People Mover), had a faulty starter.  This took some days to find out.  The car was parked in our porch for quite some time.  The problem was trying to get it to a workshop that could handle the problem.

Initially I thought it was a battery problem and had it charged using our solar panel system.  On one weekend I managed to start it.  Since it had been a while, I decided to drive it around Putrajaya.  I thought the charging system/alternator was causing the battery not charging.  Then I stopped at a shop close to our house to buy a pack of cigarettes.  I was feeling quite confident that I had solved the problem upto the time when I failed to fire the engine up.  It was up to me to get the car fixed.  On a Christmas day.

I drove around and found a workshop that only closes on Fridays.  They had a team of two mechanics come over our house in about an hour.  I was chuffed.  I drove the other car to see them having a go at it.  I explained what I suspected.  They went on to hammer the starter but could not give it life.  A replacement was all it needed and it worked.  It was not exactly the same Hyundai starter.  It was a reconditioned starter from a Proton Perdana.  I understand that all it needed was torque and matching helical gears.  No problem.  RM 300 including labour and gave them RM20 for being good boys.

This lengthy story leads now to using that motor in a Start-Stop system.  I am not so fond of having to use a bigger battery.  The Hyundai Trajet uses a DIN55 battery as it is.  Two big batteries then?  The Trajet is worth it to make it go better.  Why not?

A Start-Stop system would need:-

  • Input contact from the accelerator
  • Input contact from the brake (or get input from the brake switch)
  • A programmable controller with a timer activated relay.
  • A motion sensor

Sounds more like you could have all those on an Arduino board.  Yes?  Anybody who is serious enough could do it then.  You would also need to know a bit about programming. I shall delve into my deepest memory of BASIC programming on a Sinclair Spectrum 48K to do a bit of this.

Arduino UNO

Arduino UNO. A developmet board. Its supposed to be for prototyping. But nobody said you can’t use it permanently

ACL = 0, BRK=0, TMR = 100; IGN = 1

For i = 0 to TMR

PEEK 681091; IGN:  PEEK 681092; ACL:  PEEK 681093; BRK

IF ACL > 0 AND IGN < 1 THEN Next A

IF BRK > 0 THEN GOSUB Starter Motor




SUB Starter Motor

FOR t = 1 to 10

POKE 681094; 255



I am just toying with this idea.  BASIC is something that I have left for close to 30 years.  Sorry if it is wrong.  But I understand the requirements of the logic and I would not think if it was long.  I would like to think of this as an excuse to get a micro controller installed for some other fuctions which I have in mind.


NASA ADS: Influence of fuel temperature on atomization performance of pressure-swirl atomizers

NASA ADS: Influence of fuel temperature on atomization performance of pressure-swirl atomizers.

I have been going through the publicly accessible data throughout the internet on the difference in fuel consumption of caricatured engines and fuel injection.  All point to the possibility that carbed engine CAN be much more efficient.  The web leads me to websites that allegedly champions the carb.  When you go through the details there is always an air of a Conspiracy Theorists.   People were saying that the technology for 200mpg engines existed for decades and it was just the big corporations did not want to see it happen.

I have my own perception on these so called energy savers.  Its not truly a carburetor. It is more of an evaporator.  The thinking that gasoline does not burn as a liquid is a known fact.  Carburetors are bad at making small droplets as there are no effect that could separate the layers and the surface tensions of liquids.  But carbs work when you need power.  They were and still are effective to give you the power that you want.  Not the economic side though.

Doing another search revealed that much has been known of the effect of higher temperature on fuel.  It has been archived by Automotive Engineers


It may seem that using microwave to heat up a sample of fuel a bit over engineering but they have always been known to do so.

This NASA link however is not a full report on the study but it does indicate for temperatures between -20 to 50degC, there is an effect on droplet size.  Although the full report would make a compelling reading, suffice to say that it has be researched.

Two separate results from two different engineering entities should lead me to somewhere close to heart.  A simple solution. It cannot be as simple as my previous ones but it should save money and it should be simple for most people to make themselves.