Yesterday I called Honda breakdown (the AA) out to my non starting car which was on my drive having been pushed from the garage. The yellow van arrived within 15 minutes and on explaining the problem to the AA guy his reply was " It sounds like a regular Monday morning callout for a flooded engine after weekend driveway shunting". It sounds obvious now but repeated short engine runs on full choke thanks to the engine ECU is not a good idea. The AA guy told me if it happens again the way to start my car (I don't know about others) is to start it with the accelerator fully depressed as this shuts off the fuel during starting to protect the engine from high rev starts and release the accelerator when the engine fires and the engine will run.
And I thought that sort of problem went with carburettors and manual chokes, silly me! Three decades of diesel driving obviously blunted my petrol instincts.
Last edited by: Old Navy on Sun 21 May 17 at 20:25
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We had that problem about 10 years ago with a Fiat Panda we had in the family. Exactly that - started and moved a short distance two or three times.
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Never a good idea to switch off an engine until it fas warmed up. Worst thing you can do is shunt it up and down the drive.
Last edited by: CGNorwich on Sun 21 May 17 at 20:34
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It is not a problem I have had up until now. I have had a choke knob or a diesel engine. The computer said no, difficult to dispute but it won't happen again. The AA guy said avoid switching off a cold petrol engine.
Last edited by: Old Navy on Sun 21 May 17 at 20:43
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Yes. I had the same aggro with daughter's Yaris.
Call out man related the same story but said for some reason SAABs did not cause the problem.
Yes. Sunday, back it out of the garage, wash it, polish it and pop it back in its snug. Next day a dead motor.
After many failed tries he said the next action was to pull the fuse for the fuel pump or disconnect i
it and give it some wellie. One last try and it fired up.
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The lancer would always start in a couple of revolutions of the starter. Sometime that led me to turning the key off before it had fully fired. Always, without fail the engine would be flooded if i did this, and would take two minutes of cranking to fire it up, with the smell of fuel.
It was my fault every time.
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Cranking the engine with the accelerator depressed will activate "flooded" mode in the ECU
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That makes sense, must be what the AA guy was referring to.
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I first came across this problem with a Nissan Micra K11. They were apparently notorious for it. I also found the fuelling was 'switched off' if the throttle was fully opened. Impressed the family when I sorted it each time.
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Here is a useful guide to various ECU modes of operation.
www.gmtuners.com/tech/modes.htm
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>> Here is a useful guide to various ECU modes of operation.
>>
>>
>> www.gmtuners.com/tech/modes.htm
>>
Thanks for that, although I knew some of that it is helpful to a computer controlled engine geriatric virgin.
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I've never had that with a carburetor engine with a real choke. I fire it up with lots of choke, and then push the choke in until the engine idles nicely with minimum choke.
There's no excess fueling and no flooding.
Automatic chokes were notorious for over-fueling, but the fix was to scrap the thermostatic gadget and fit a manual choke.
Progress.
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As for fully depressing the accelerator I dimly remember that this was also recommended in my 1970s BL cars. So not just modern ECU equiped cars. Seems counter-intuitive but someone more technically knowledgable might comment?
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On carburettor fitted cars it would open the throttle wide to allow maximum airflow through the engine while starting to clear the excess fuel. On modern cars there is no mechanical link between foot and throttle valve.
Last edited by: Old Navy on Mon 22 May 17 at 08:49
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I don't know, I bet there's a few new cars with ecu and a cable connected to the throttle.
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There is a slight difference between computer controlled electric string and a Bowden cable.
Last edited by: Old Navy on Mon 22 May 17 at 09:01
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Correct, not all ECU controlled cars are the same.
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I vaguely remember a temporary fix for a broken throttle cable which involved redirecting the bonnet release cable and controlling the engine revs with the bonnet release knob. Try that with an ECU.
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>> I vaguely remember a temporary fix for a broken throttle cable which involved redirecting the
>> bonnet release cable and controlling the engine revs with the bonnet release knob.
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Many moons ago on holiday in Malta the Avenger hire car, when out of town came to a halt one "lunch time".
No instant help available so, on investigation I found a nut had fallen off the mechanical linkage to the carburetor.A copious amount of string wound around the linkage was a fix that got me back to the hire co.
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With my first car, I quickly learned to never start up and shunt a car around without driving it round the block a couple of times. It's a habit that I'll never break either and I've seen people on the street, friends and family get caught out doing that.
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One of my colleagues used to have a Mazda with a wankel engine. An RX7 I think it was. From all accounts you never just got it out the garage and switched off the engine. It needed warming up else the engine could hydraulically lock up with the unburnt fuel in the combustion chambers.
Last edited by: VxFan on Mon 22 May 17 at 10:16
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"One of my colleagues used to have a Mazda with a wankel engine. An RX7 I think it was."
That's exactly the one my sister's husband had, with the little suicide doors. He's a teacher and because there were always too many teachers, too little space, if anyone needed to leave before 3.30 it meant shuffling cars around. I once asked him if it was the dream car that he'd always wanted, he said yes but it keeps breaking down at school for some reason. Breaking down?, I asked. Yes, he said, it keeps happening if I just move it to let another teacher out early.
Don't be the last person arriving at school then, dummy.
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>> with the little suicide doors
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Probably an RX8 ...
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We all knew what "you've flooded it!" meant in the carburettor days, but what caught me out with the Panda was that I had never had that problem with a car with an ECU, and assumed that something else was preventing it starting due to lack of fuel or spark.
It's quite a smart idea to make the remedy the same - crank it with the throttle wide open. Had I been either more ignorant or less ignorant of how the car worked, that is exactly what I would have done instead of sending for the RAC man to do it.
In my banger days, it was always the Fords that were "bad starters", the BMC cars usually started on the first crank if they were going to. SUs of course don't have accelerator pumps, and I think that was probably a large part of the difference.
I had an Escort that could be a pig to start, until by trial and error I discovered that two pumps, then holding the accelerator to the floor before touching the key then cranking it was infallible. I think that was the routine; anyway, whatever it was, when I randomly looked at the manual one day I found that was the manufacturer's recommended method for cold starting.
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>>In my banger days, it was always the Fords that were "bad starters",
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My 1600E was a brilliant starter every time.
It had as standard a "cold start" coil set up.
I.e. a 9 volt coil. when cranking 12V was fed to the coil and when the key was released a ballast resistor dropped the volts back to 9 for normal running.
My later Ford had the dreaded auto choke so the carb was swapped to a Webber with a manual choke - sorted.
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>> With my first car, I quickly learned to never start up and shunt a car
>> around without driving it round the block a couple of times. It's a habit that
>> I'll never break either and I've seen people on the street, friends and family get
>> caught out doing that.
>>
That's something I do too. If I have to start the car to move it I always give it a long enough run to at least get the temperature needle off the floor. It annoys the hell out of Mrs O'Reliant when I wash her car by the side of the road and then disappear for a drive on her fuel before parking it on the driveway.
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Wash her own fuffing car then. Wimmen eh!
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>> Wash her own fuffing car then. Wimmen eh!
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It's that or the dishes.
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Good point well made Sire.
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>> There is a slight difference between computer controlled electric string and a Bowden cable.
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True, but it doesn't need either. Opening the throttle wide is a last resort when you have already flooded the engine.
All it needs is a management system that can adjust the start-up mixture to meet the circumstances. The problem was solved over 50 years ago by means of a knob on the dashboard.
But I thought the warning about restarting a modern car was that the necessarily richer starting mixture contaminated the catalyst, which if not burnt off by continued running until warm had to be left to evaporate or else damage would result. The ECU is clever enough to realise that so prevents immediate restart.
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I think you're right Cliff...the RAC bloke said that the behaviour was intentional to protect the catalyst...I'd forgotten that.
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My first car was a '68 Beetle, I lived at the bottom of a hill, in the winter the auto choke snail cam would flip over as I went up the hill at 7am so I had to stop at the top and run around to the back with the engine doing 3000rpm plus to flip the flipping thing back. Not the quietest thing Beetles, the people who lived at the top of the hill must have cursed it.
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I was often called out to cars which wouldn't start. If it was in the depths of winter I would whip the plugs out then spin the engine over and ask the punter to stick the plugs in the oven ... while he was making the tea :)
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I had a Volvo 850 GLT that if moved in the manner aforementioned and turned off refused to start, end of. It could flatten one battery without starting then required jump leads and eventually it may have started with a flat to the floor throttle, but it was a pain in the derrière.
I let an employee use it and informed him of the likely situation. One day he called to say it wouldn't start and I called him a liar. I told him that he'd moved it and turned it off which he vociferously denied. I stood my ground, he capitulated and because he had wrecked an early start on a very important day he was given the tin tack.
The moral of the story is never try and kid a kidder.
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Seems like it only affects Japanese cars then?
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Pandas aren't Japanese.
More likely a function of what Bosch/Denso/Delphi or whomever have programmed into them, and they are probably mostly similar. And petrol of course.
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>> Pandas aren't Japanese.
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No they're Chinese aren't they ...
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>> Seems like it only affects Japanese cars then?
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The link above shows that GM ECUs have a "Clear flood" mode.
Last edited by: Old Navy on Fri 26 May 17 at 13:15
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Happened to my 1.8 A4 once after moving it on the drive. Had no idea you could flood a modern car with ECU until it happened.
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It never happened when I had a car with a manual choke, these modern electronic infested cars are obviously a different matter. They do run better than pre electronic cars once they have decided they are going to start. At least there is an easy fix, pity it is not in the handbook!
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>> Had no idea you could flood a modern car with ECU until it happened.
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I suppose "flood" just means the plugs are wet with petrol?
If that's the case, I'd have thought it would dissipate away over a few hours, but seems that's not happening.
I wonder if it might even be condensation that's there, from the short run-time of a stone cold engine?
Last edited by: Bill Payer on Fri 26 May 17 at 15:34
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The ECU starts a cold engine on full choke. Repeated cold starts literally floods the engine with petrol. If the plugs are wet with fuel they will still spark but if the mixture is too rich it will not burn.
Last edited by: Old Navy on Fri 26 May 17 at 15:57
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>> The ECU starts a cold engine on full choke. Repeated cold starts literally floods
>> the engine with petrol. If the plugs are wet with fuel they will still spark
>> but if the mixture is too rich it will not burn.
The point is it's programmed not to start in certain circumstances. It might be flooded, it might not. If it was just the excess petrol it might start, it might not, and it would probably cough and splutter a bit; but the ignition and/or fuel are cut off for a period to protect the catalyst from unburnt fuel. It's as good as dead, or immobilised, which is why people (as I did, ignorantly) so readily call the breakdown service.
This protection is overridden, and probably other parameters changed, when the pedal is held right down - again, because it's programmed that way.
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I can't push the choke in! - Manatee
