Advice for a newbie

[kingnothing]

Hi all,

I was given a car last year by a friend and I was taking lessons but with the 'rona pandemic I've had test after test cancelled so I haven't got my license yet. It's been a bit of a nightmare really. Anyway, I have a 2000 Corolla 1.4 hatchback and as it wasn't getting any use during the lockdowns, I was letting the car run for 20 minutes (to keep charge in the battery) every week just parked up outside my house. Fast forward to about a month ago and the engine started dropping revs and felt as though it was on the verge of stalling; up until then it was running great. Then a couple of weeks ago a check engine light was illuminated on the dashboard so I did a bit of research and found that you can check what is causing the check engine light to come on with an OBD2 reader. I borrowed a code reader from someone at work and when I went to check my car last night, she was completely dead. So my question is, what should I do next? Do I need a new Battery or can I charge it up? Can I jump start it to charge the Battery? 

Cheers,

Tom. 

[TonyHSD]

Hi, 

you can charge the Battery properly with charger or jump start the car, let it run for a while and in the meantime do check for fault codes with your diagnostic tool, see what codes will come up and you will take it from there. It may need just a new Battery or some sensors or spark plugs or coils, or perhaps may need some diy cleaning like throttle body and sensors., new air filter, can be anything but diagnostic is the starting point. 
Good luck 

[kingnothing]

54 minutes ago, TonyHSD said:

Hi, 

you can charge the battery properly with charger or jump start the car, let it run for a while and in the meantime do check for fault codes with your diagnostic tool, see what codes will come up and you will take it from there. It may need just a new battery or some sensors or spark plugs or coils, or perhaps may need some diy cleaning like throttle body and sensors., new air filter, can be anything but diagnostic is the starting point. 
Good luck 

Thanks Tony,

my concern is that if I jump start the engine and let it run ,while there is a fault light on, will this not be bad for the engine?

[TonyHSD]

Just now, kingnothing said:

Thanks Tony,

my concern is that if I jump start the engine and let it run ,while there is a fault light on, will this not be bad for the engine?

Should not be a problem, but if unsure you can connect jump cables put ignition into acc mode no need to start the engine and do diagnostic first to check what fault codes are and then if you want you can jump start it. If you are afraid doing it that way then best to recharge the Battery with external charger., or replace the Battery. Sometimes fault codes can be triggered by low voltage in the car electronics, but again you will need somehow to read the codes first. 👍

[kingnothing]

1 hour ago, TonyHSD said:

Sometimes fault codes can be triggered by low voltage in the car electronics, but again you will need somehow to read the codes first. 👍

I'm guessing low Battery voltage wouldn't cause the engine to drop revs while running though would it?

[TonyHSD]

2 minutes ago, kingnothing said:

I'm guessing low battery voltage wouldn't cause the engine to drop revs while running though would it?

Perhaps not, but run the diagnostic first and then you can have a better clue. 

[oldcodger]

Hi,

Agree with what @TonyHSD has said, but a couple of general pointers.

When you  say you let the engine run for 20 mins to charge the Battery, are you letting it run at idle speed, eg around 650 rpm?  - if so that will not really do a lot of charging, its better to keep the revs above 1200rpm.

In your situation think using a Battery charger would be a better way, loads of cheap "smart" charger on the usual sites eg £11, use one myself.

Also try and see how old the Battery is, if its more than 5 years then it worth replacing for something decent.

If the battery is disconnected  for a while or runs low, the ECU can loose its way and reverts to "learning mode", so you will find at low revs it really drops very low, sometimes stalling, it needs a drive for a few miles to re-lean.

The Engine Check light error code will be lost oif you disconnect the battery, though I would not worry about it as its probably to do with the battery problems, if not it will come back on again.

If you finally get a new or rechaged battery fitted, its worth checking that the alternator is charging properly.  This can be done with a simple volt/multi meter test which should show around  14.2v DC across the battery terminals, but you must up the revs to around  1200 -2500rpm.

 

[dannyboy413]

One thing to bear in mind Tom, you do not have a licence. I am sure you have thought of that, but if the necessary tests etc need to be done on a public road, get someone else to do them.

[kingnothing]

16 hours ago, oldcodger said:

When you  say you let the engine run for 20 mins to charge the battery, are you letting it run at idle speed, eg around 650 rpm?  - if so that will not really do a lot of charging, its better to keep the revs above 1200rpm.

I'm pretty sure it was idling at around 900rpm and I was giving it any gas. Someone actually told me not to rev it if the car is not moving as it can flood the engine. Not sure how true that is. 

16 hours ago, oldcodger said:

In your situation think using a battery charger would be a better way, loads of cheap "smart" charger on the usual sites eg £11, use one myself.

Could you recommend a smart charger? I don't really have a clue what I'm looking for. Also, can I remove the Battery to charge it as I would struggle getting a power lead to where my car is parked?

 

16 hours ago, oldcodger said:

If the battery is disconnected  for a while or runs low, the ECU can loose its way and reverts to "learning mode", so you will find at low revs it really drops very low, sometimes stalling, it needs a drive for a few miles to re-lean.

Good to know and could well be the issue here. 

 

16 hours ago, oldcodger said:

If you finally get a new or rechaged battery fitted, its worth checking that the alternator is charging properly.  This can be done with a simple volt/multi meter test which should show around  14.2v DC across the battery terminals, but you must up the revs to around  1200 -2500rpm.

Thanks, I'll do this. Thanks for all your other advice too, I realise I've got a lot to learn. 🙂

[kingnothing]

16 hours ago, dannyboy413 said:

One thing to bear in mind Tom, you do not have a licence. I am sure you have thought of that, but if the necessary tests etc need to be done on a public road, get someone else to do them.

Do you mean like checking the Battery voltage when you say 'necessary tests'?

[oldcodger]

Hi,

1.  Not sure if you have injectors or carbs, but flooding not been a problem I have ever experience from reving any engine a bit ??

2. Bought one of these cheapies, a few years ago, see pic below,  currently £11 delivered, works fine for us, plenty around with various brand names.You can spend lots more if you wish, Ctek are currently the best on the market  if you want to splash the cash .  Better to remove the Battery to charge it from flat. might take 24hrs to full charge  / follow the chargers instructions.

3. When starting up any car the 'auto choke'  keeps the revs higher, up to 1200rpm, until it the temperature is increased, after that it should slowly drop and typically idle at around 650-700rpm, but the Corollas can feel a little lumpy at 650rpm though thats not unusual.

 

 

 

[c90]

It was a problem with car standing during the pandemic, but I did manage to get at least a 30 minute run nearly every day throughout the pandemic.

I don't like revving car or bike while standing.

[dannyboy413]

On 8/3/2021 at 11:33 AM, kingnothing said:

Do you mean like checking the battery voltage when you say 'necessary tests'?

No, I just meant any tests that you might carry out on a public road. If the tests are carried out 'off road' it does not matter whether you have a licence or not.