In <
[email protected]> Alex wrote:
> Odd that, but how many of your vehicles with electronic ignition get
> the electronics immersed in water? With the possibilty of mistakes
> whilst fording etc, and the amount of water and mud thrown up under a
> landrover bonnet I'd prefer a set of points. At least you can dry them
> out and carry on, which is not an option with shorted electronics.
The electronic systems are a lot tougher than most people think and are,
in most cases, better equipped to withstand water than their
"mechanical" equivalent. The electronic distributors, for example, use a
halle effect sensor that is fully sealed and a ring that spins around
near it. There is no mechanical contact between the two. Unlike a points
system there is nothing to wear out in there so faults are very rare.
OUtside the distributor you have an amplifier which, again, is fully
sealed against water. These can fail but having run these distributors
in a number of vehicles over the last 12 years I have yet to have a
failure.
> I drive landrovers largely because of thier ability to be fixed at the
> roadside, and anything electronic tends to negate that ability. I'd
> like to see someone cure a fuel blockage in a EFI engine with nothing
> more than one screwdriver at the roadside, which is something I have
> had to do with my carb on more than one occasion. And I've lost count
> of the number of times I've had to take a screwdriver to the points on
> various landrovers. At least mine CAN be fixed at the roadside, and
> for bugger all cost as well.
I think, to a certain point, you have pointed out (if you'll excuse the
puns) the flaw in your argument.
As far as a fuel blockage is concerned, EFi systems cope much better
with bad fuel than a carb because they have much better filtering and
work at higher pressures. They don't have moving parts that can get
blocked such as the float valve system on most carbs and they force fuel
through their jets (injectors) at extremely high pressure rather than
depending on passing air sucking fuel droplets out. In the last 5 years
of running an EFi in challenge competitions, trials competitions and
general road use I have had one breakdown.
That particular breakdown was nothing to do with the EFi as such but was
caused by a badly routed vent pipe on the fuel tank syphoning water in
while I was crossing a bonnet deep lake. (
http://www.
yorkshireoffroadclub.net/gallery/muddy_truckers/ for the gory detail).
Despite the ECU being completely submerged for about 5 minutes and the
fuel pump putting several gallons of muddy water through the filter and
injectors the vehicle was still able to compete the following day after
we had put clean fuel in it. The fuel pump failed at the end of the
following day but when I was running carbs with a FACIT fuel pump that
was an annual occurance.
I've never had to take the distributor cap off mine other than to wipe
condensation out after deep wading or during a normal service.
Whilst it is true that if something in the electronic breaks internally
that the ECU can't cope without you are pretty much stuffed, IME the
chances of something actually breaking and forcing you to stop are much
less than with a conventional setup. Even if you "lose" a major
component such as the air flow meter the ECU will drop into "get you
home" mode and allow you to continue driving. My regular team mate runs
the same ignition system as me but has carbs fitted. Over the past few
years competition we have spent a lot more time with the bonnet open on
his motor than mine, unblocking breather pipes adjusting fuel return
restrictions, tweaking the mixture etc... His vehicle also copes less
well with deep water than mine for some reason and has had a history of
struggling to cope with extreme angles (usually when hanging nearly
vertical on the end of a winch rope) when the engine will often die.
We each have our own preferences and our own views and I have to admit
that my first EFi Land Rover scared me to death with it's apparent
complexity. Now I have swapped carbs and points for EFi and electronic
ignition I wouldn't go back to a carb system. I'm about to replace the
distributor with a distributorless ignition system too so I can improve
it's deep wading performance.
cheers
Dave W.
http://www.yorkshireoffroadclub.net/
