ECU. do we need them?

James.UK · Unread post by **James.UK** » 17 May 2006, 16:17

It seems that more and more of our forums are being taken up with trying to solve complex elec gremlims...

Having read someones comment that they would "remove the air con and chuck the lot in the bin" -- Could this be done with ECU stuff? remove and dump the lot in the bin?

If so... I may get a newer car.. lmho

8)

bxbodger · Unread post by **bxbodger** » 17 May 2006, 16:35

Not without some serious re-engineering...........you'd need a coil and a distributor:the old fashioned type with a rotor arm and mechanical advance by centrifugal bob-weights plus a vacuum advancer, so you'd need to rig up a drive for it from the camshaft, then chuck the injection manifold and get yourself a nice old carburetor or two to fiddle with: I prefer SU's or Strombergs for ease of set up, try to avoid any French carburetor, they're rubbish...............nearly forgot, drill a hole in the dash for the manual choke cable!!!

Then of course you'd likely fail the emissions test...

The alternative is to buy a pre 1972 car- you get all the above, plus free tax disc,no depreciation, and a bit of style too!!! 8)

Plus of course dodgy handling, crappy heater, lousy brakes, archaic dynamo charging system, abysmal fuel economy figures..............

Sl4yer · Unread post by **Sl4yer** » 17 May 2006, 17:33

I think we do need them. Cars are much more fuel efficient and produce lower emissions that in the pre-injection days.

I'm sure that cars are much more reliable than they used to be as well. It's just that there is often little you can do about it when they do break down!

I remember the trouble my father used to have with his Cortina. It was high mileage (for the time anyway, over 150,000) and broke down regularly. Most modern cars don't flinch at that sort of mileage, and will still start in the morning if the battery is charged!

I suppose modern cars lack character though, and I guess men liked to spend Sunday afternoons under the bonnet!

James

Homer · Unread post by **Homer** » 17 May 2006, 18:27

After spending many a happy hour rubbing things with emery paper and blowing through various tubes I would say yes we do need them.

bxbodger · Unread post by **bxbodger** » 17 May 2006, 22:34

here's a C5 engine-

Heres my Triumph engine-

There's 40 odd years and 2 cylinders between these two, and although basic principals are the same the C5 motor is obviously going to be a whole lot more fuel efficient,reliable, cleaner and quieter- thats what the elastictrickery is for, but I know which would be the easiest to fix out of them (albeit a lot more regularly) ......and which one sounds best

Seriously, though, the past is a great place to visit on a nice Sunday afternoon, but we forget that its not that long ago that it was not guaranteed that a car would start on a cold wet Monday morning-something we now just take for granted- and how often nowadays does a desperate neighbour knock on your door for a jump-start??

James.UK · Unread post by **James.UK** » 18 May 2006, 10:29

Hmmm I was being semi serious.

My ZX doesn't have an ECU that I know of? And it passes all the tests, is very economic, reliable, and in my opinion, quite a nice car to drive.

Soo. is it possible to strip all the ECU gubbins out of say -- a 1.9D Xsara
and still be able to get the car to perform and work OK?

I realise a petrol engine is a diff story, but I wouldn't buy a petrol engined car by choice anyway..

One of my main objections to ECU's is the fact that an unscrupulous dealer could programme faults into the car anytime and the poor customer would just keep paying for it to be put right and never know they were being conned,

Another worry is .. Based on how unreliable many PC software programmes are, I just don't fancy having one in control of my car!!

Last, but not least of my worries, is the fact that I know zilch about electrics, I can fit a 13amp plug and change a fuse, that's it..

So if I bought a car with an ECU fitted and it played up, I would be completely at a loss as to how to sort it..

At least in the good ole days we could fix almost anything with a screwdriver, hammer, and a big pair of pliers so that it would get you home.

fastandfurryous · Unread post by **fastandfurryous** » 18 May 2006, 11:40

I agree with you.

Although my 405 does have some electronics, they're not for essential systems. I am slowly ridding the car of them, eg:

The Bitron is being replaced with a radiator thermal switch and relays
The Climate control is replaced with manual levers

The only one I can't easily remove is the ABS... but that seems moderately reliable.

Other small amounts of electronics like the outside air temperature are not a problem, mainly because they're discreet systems, and not massively integrated like a multiplexed car. A fault in the CD player for instance won't affect anything other than the CD player (Unlike a 'plexed 406 where the whole car goes and has a sulk)

The bit that annoys me is that with ECU systems, the car manufacturers won't allow the average joe public to connect to their car and see what's going on with it. I know it's possible to have a bit of software on your pc and a bit of serial cable to connect the pc to your car.... but the manufacturers won't allow it.

Plus... how much does an ECU cost? several hundred pounds. Considering that you can now buy a (much more powerful) motherboard for a PC for about £30, I think that's a bloody rip off.

IF you could buy the ECU for £30, and connect to it via USB from a PC, then I wouldn't have a problem with it. This IS possible, just not done by manufacturers.

Still wouldn't allow the ECU to have systems like ESP though. I don't want ANYTHING else to have individual control over my brakes thankyouverymuch!

Sl4yer · Unread post by **Sl4yer** » 18 May 2006, 11:45

A modern diesel needs the ECU to control the injection properly. The solenoid systems used are much more accurate, and work at much higher pressures, than the traditional mechanical injection pumps.

ECU control is supposed to reduce the emissions too, but I see as many electronic diesels smoking as their older cousins.

Modern diesels actally inject twice per power stroke to reduce the diesel clatter - this would be impossible to do with a mechanical system. Saying that, the Seat is much more clattery at idle than the ZX!

James

bxbodger · Unread post by **bxbodger** » 18 May 2006, 11:47

I don't want ANYTHING else to have individual control over my brakes thankyouverymuch!

Oh, I don't know, when you're in a hydro Cit, you're opening a little hydraulic valve and letting a bag of gas crammed by a Frenchman into a green metal globe do the job for you...!!

fastandfurryous · Unread post by **fastandfurryous** » 18 May 2006, 11:51

Sl4yer wrote:Modern diesels actally inject twice per power stroke to reduce the diesel clatter - this would be impossible to do with a mechanical system.

I recon you could do it... with a two-stage cam arrangement. All it requires is some clever machining of the cam-ring in the injection pump, and hey presto, 2-stage injection.

The problem is that it would cost. ECU's and electronics are cheap. Super cheap.

If you compare the MANUFACTURE cost of a Diesel injection pump & mechanical injectors and an ECU & set of electronic injectors, guess which comes out a whole load cheaper?

ACTIVE8 · Unread post by **ACTIVE8** » 18 May 2006, 12:06

If we didn't have the progress that has been made over the years with diesel engines now being of a common rail design with precise ECU control.

Then we would not have the power outputs with the increased torque, that we now have which make the cars with common rail engines even more of a pleasurable driving experience, than the previous generation of diesel engines.

After driving a common rail engine vehicle you certainly notice the difference, and if it's intercooled and turbocharged then it makes it even better.

Sales of diesels in the past were not at the level that they are now, increased power, and economy do help to make drivers consider a diesel whereas in the past they would not have been tempted.

So we do need the ECU !

bxbodger · Unread post by **bxbodger** » 18 May 2006, 12:25

Electronics in Diesels serve two purposes, one, they're cheaper than mechanical bits, but the second purpose is to make the cars drive like petrol cars, and thats what people want.

I doubt you'd be able to get away with selling something like my n/a BX today.

I have absolutely no problem with having cars stuffed with electronics- in general they are a zillion times more reliable than oily bits like a condensor'n'points set up.

My gripe is with the manufacturers who seem to think it's O.K. to charge 70 or 80 quid for a sensor made in a Chinese factory for 20p, or scam you 300 notes for an airflow meter or an ECU board...its just greed as these things cost next to nothing to make.

The trade's been a bit slow on the uptake as well and seem to fault find by substitution. Not a problem if the bits are cheap, but when they are being priced up in the hundreds before the labour charge even goes on......

ACTIVE8 · Unread post by **ACTIVE8** » 18 May 2006, 12:45

Yes, an ECU managing an engine, diesel or petrol does improve it a great deal.

Although the cost of the parts is OTT they do not cost that much to make, and the companies charging so much for an ECU etc need to reduce their prices a great deal, to what is a more acceptable level.

PowerLee · Unread post by **PowerLee** » 18 May 2006, 20:57

fastandfurryous wrote: The only one I can't easily remove is the ABS... but that seems moderately reliable.

Unplug an ABS sensor to switch the system off & go back to standard braking.

Just plug it back in for MOT time to get the correct ABS check light sequence.

The grey 2 pin ABS sensor connector near the passenger side headlamp is the easiest one to get at on the 405

pugxpert · Unread post by **pugxpert** » 19 May 2006, 07:52

Be carefull if you disconnect abs sensor to disable system especially if car has EBFD electronic brake force distribution ,these cars have no brake load compensator higher pressure to the rear on braking and if wheel locks ecu will regulate,so if you un plug sensor to disable system there is good chance you will lock a rear and spin!!! had it happen to me whilst driving a 307 on road test with abs light on