Trouble Restarting Engine After Stalling?

[Mackass]

The engine revs go up so extra fuel is added by the engine management ready for the higher engine speed and hence more fuel requirements, however your clutch control suddenly stalls the engine and this extra fuel doesnt get burnt.

When you come to start the engine again this extra fuel make it difficult for the mixture to ignite. Its taking a while to start as when your cranking the engine over the air is 'cleaning' the extra fuel out and then it can start.

Try opening the throttle a little when you start it to let more air in.

Thanks Simon.

So, before turning the ignition, I would press down on the gas a little, and keep it at that position until the engine turns over? If so, how far down do I need to press the pedal until the throttle opens enough for the extra air to get in? I would guess 2/3 inches, would that be enough?

Also, do you have any ideas why some cars can restart straight away without needing to 'remove' the excess fuel?

 

[Simon]

Thanks Simon.

So, before turning the ignition, I would press down on the gas a little, and keep it at that position until the engine turns over? If so, how far down do I need to press the pedal until the throttle opens enough for the extra air to get in? I would guess 2/3 inches, would that be enough?

Also, do you have any ideas why some cars can restart straight away without needing to 'remove' the excess fuel?

I'm just guessing at that theory, might not be right.

All depends on the car/engine/ecu. Personally I wouldn't worry about it and just try not to stall as much.

 

[L0rdMike]

Thanks Simon.

So, before turning the ignition, I would press down on the gas a little, and keep it at that position until the engine turns over? If so, how far down do I need to press the pedal until the throttle opens enough for the extra air to get in? I would guess 2/3 inches, would that be enough?

Also, do you have any ideas why some cars can restart straight away without needing to 'remove' the excess fuel?

It depends on what your pedal is like, 2-3 inches is likly to red line it.

You only need a few cm's

Did you mean two thirds of an inch?

 

[Mackass]

I was gonna say.....my clutch is practically digital and operates an inch off the floor yet I don't stall it

My biting point is quite high up though, which makes it a little more tricky. But as I said, I've only been driving for a couple of weeks, over time I shouldn't stall.

 

[Mackass]

I'm just guessing at that theory, might not be right.

All depends on the car/engine/ecu. Personally I wouldn't worry about it and just try not to stall as much.

But will the theory work though?

i.e. will I be able to restart the car quicker this way by opening the throttle?

 

[L0rdMike]

But will the theory work though?

i.e. will I be able to restart the car quicker this way by opening the throttle?

Only one way to find out.....

 

[Mackass]

It depends on what your pedal is like, 2-3 inches is likly to red line it.

You only need a few cm's

Did you mean two thirds of an inch?

Yeah, kinda the same amount of gas as I would use when moving off, which is around 1500RPM or so.

Sound about right?

 

[Mackass]

Only one way to find out.....

Will it do any harm?

Starting the engine with the throttle partially open?

 

[L0rdMike]

Will it do any harm?

Starting the engine with the throttle partially open?

If it does im screwed as I do it when its wet, if I dont one of my belts slip.

Really dont think it would do any harm.

 

[Mackass]

If it does im screwed as I do it when its wet, if I dont one of my belts slip.

Really dont think it would do any harm.

Alrite cheers mate.

First I'll make sure not to stall it anymore, secondly I'll try that method if I have one of those off days.

 

[thedazman67]

This happened to me once, i got out from work started the car less then a minute later i had to slam on the anchor to avoid 2 chavs on bikes riding straight in front of me. I tried to restart the car imediately after it would turn over but not fire. i left it for a couple of minutes then started fine with a bit of throttle applied while starting.

thedazman

 

[saitrix]

I was gonna say.....my clutch is practically digital and operates an inch off the floor yet I don't stall it

I stall it. I would have been fine with more practise!

 

[Lashout_UK]

Aye, you needed no excuse it's not the easiest thing to drive by far

 

[Mackass]

This happened to me once, i got out from work started the car less then a minute later i had to slam on the anchor to avoid 2 chavs on bikes riding straight in front of me. I tried to restart the car imediately after it would turn over but not fire. i left it for a couple of minutes then started fine with a bit of throttle applied while starting.

thedazman

Imagine that happening in busy traffic.

 

[CypherPunk]

Firstly a fuel injected engine should not get flooded (excluding Mazda rotary engines), assuming you don’t stall in the first couple of minutes of driving on a cold engine it shouldn’t happen, and it definitely shouldn’t happen every time you stall, thedazman67 gives and example of when an engine will flood, a very harsh stop on a cold engine without using the clutch will flood an engine, stalling while pulling away shouldn’t.

What causes the excess fuel if you don't mind me asking? Also, how does that prevent me from restarting the engine straight away, as I've managed to do this before, but now now. Could I get this fixed at a garage?

If the problem has only started recently I think that also shows that something is amiss, it could just be that the engine is running rich, which would increase the chances of it flooding, have you worked out your fuel consumption recently? If it seems higher than it should be then this could be the source of your trouble.

You can usually tell when an engine has flooded by the characteristic sound it makes when you eventually start it, one cylinder at a time will begin to fire so the engine sounds like it is almost stuttering back into life.

Also starting an engine with the throttle pushed down or pumping the throttle can actually cause it to flood, if the engine is turning over without ignition occurring then opening the throttle will simply cause more fuel to be pumped into the engine. If, for example, you have no spark, holding the throttle down while cranking the engine for an extended period of time will increase the compression because of the excess fuel in the cylinder, which can lead to all sorts of trouble.

 

[Mackass]

Firstly a fuel injected engine should not get flooded (excluding Mazda rotary engines), assuming you don’t stall in the first couple of minutes of driving on a cold engine it shouldn’t happen, and it definitely shouldn’t happen every time you stall, thedazman67 gives and example of when an engine will flood, a very harsh stop on a cold engine without using the clutch will flood an engine, stalling while pulling away shouldn’t.

If the problem has only started recently I think that also shows that something is amiss, it could just be that the engine is running rich, which would increase the chances of it flooding, have you worked out your fuel consumption recently? If it seems higher than it should be then this could be the source of your trouble.

You can usually tell when an engine has flooded by the characteristic sound it makes when you eventually start it, one cylinder at a time will begin to fire so the engine sounds like it is almost stuttering back into life.

Also starting an engine with the throttle pushed down or pumping the throttle can actually cause it to flood, if the engine is turning over without ignition occurring then opening the throttle will simply cause more fuel to be pumped into the engine. If, for example, you have no spark, holding the throttle down while cranking the engine for an extended period of time will increase the compression because of the excess fuel in the cylinder, which can lead to all sorts of trouble.

So I should really get this checked out then, as it's an indication of something not being right, if my engine shouldn't flood when it stalls. My fuel consumption hasn't really changed, I still get around 40MPG depending on how I drive it, so I don't think it's 'running rich'.

Once I manage to restart the engine, it sounds fine, there aren't any indications of the cylinders firing up one by one - if the engine does stutter or sound strange, I would definitely notice it, so maybe it hasn't flooded - but I do get a smell of petrol once I get out the car.

As for starting the engine with the throttle open, I actually done a little research and was going to question whether it will make the problem worse - sending more petrol into the engine.

Either way, I should be able to restart my engine instantly when I stall, as I've managed to do it before, so there's definitely something that's gone wrong then. I've got a three year warranty on my car, and this should be covered as a fault, so I'll get it checked out by a garage.

*Edit*

I sound as if I stall all the time, but I don't. It's easy to say don't stall and you won't encounter the problem, but the fact that there is a 'problem', I want to get it fixed.

 

[Chronos-X]

My car has a worse problem - if you stall or otherwise stop the engine after a period of cooling fan use (i.e. when crawling through a busy street slowly) - theres no turn over at all when you come to crank the ignition

This has happened 3 or 4 times now, once on a busy roundabout. All you can do is push the car to the side and wait 10-15 minutes for something to "click" and the engine will spin again like nothing's wrong. Its not like its becoming discharged, as when it will turn its not at all sluggish. I've cleaned off all the earthing points I can find - what can I do?

 

[CypherPunk]

Either way, I should be able to restart my engine instantly when I stall, as I've managed to do it before, so there's definitely something that's gone wrong then. I've got a three year warranty on my car, and this should be covered as a fault, so I'll get it checked out by a garage..

Yeah, if you've got manufacturer’s warranty use it, that's what it's there for. If the car isn't that old then it definitely shouldn't have this problem.

My car has a worse problem - if you stall or otherwise stop the engine after a period of cooling fan use (i.e. when crawling through a busy street slowly) - theres no turn over at all when you come to crank the ignition

This has happened 3 or 4 times now, once on a busy roundabout. All you can do is push the car to the side and wait 10-15 minutes for something to "click" and the engine will spin again like nothing's wrong. Its not like its becoming discharged, as when it will turn its not at all sluggish. I've cleaned off all the earthing points I can find - what can I do?

That’s a more interesting problem; do you hear anything at all when you try to crank the engine? Do you literary hear something click before the car will start? Finally does the car have an auto gearbox?

 

[Mackass]

Yeah, if you've got manufacturer’s warranty use it, that's what it's there for. If the car isn't that old then it definitely shouldn't have this problem.

It's not a manufacturers warranty, it's an additional warranty which I purchased when I bought this vehicle - which is seven years old by the way. But thanks for the advice above.

 

[Chronos-X]

That’s a more interesting problem; do you hear anything at all when you try to crank the engine? Do you literary hear something click before the car will start? Finally does the car have an auto gearbox?

Its manual. When turning the key you hear a high pitched whirring noise (very quiet) - thats it.