Car mechanics......advice please.

[sleuthey]

My money would not be on the coil pack but on a component that delivers the correct fuel to air ratio. Such as a sensor, injector or possibly the pump as said above.

If I were to take a guess I'd say the plugs are fowling up and then defoulling again when the ECU senses an over rich mixture.

Dozens of possible components. Vx diagnostics specialist sounds like a plan. Before you take it there check the very basics - clean the plugs, check air filter clean, tighten battery terminals, check fuses for pitting, use some fuel additive, try a different petrol station, check HT leads clipped onto coil pack and plugs properly.

I would not assume that a garage has serviced as per the manufacturer schedule going by my own experience.

 

[Dave7]

My money would not be on the coil pack but on a component that delivers the correct fuel to air ratio. Such as a sensor, injector or possibly the pump as said above.

If I were to take a guess I'd say the plugs are fowling up and then defoulling again when the ECU senses an over rich mixture.

Dozens of possible components. Vx diagnostics specialist sounds like a plan. Before you take it there check the very basics - clean the plugs, check air filter clean, tighten battery terminals, check fuses for pitting, use some fuel additive, try a different petrol station, check HT leads clipped onto coil pack and plugs properly.

I would not assume that a garage has serviced as per the manufacturer schedule going by my own experience.

Thanks.
50% of that is over my head but lot of it sounds right and I will try those things.

 

[I like Skol]

Do not clean the spark plugs, do not 'adjust' the gaps! Modern spark plugs don't necessarily like it.

Would guess its the alternator.

My initial hunch is close to @TissoT's suggestion and I think you should check the battery condition. Is your car still on the original battery? As the battery starts to die the drops in voltage at idle can do really odd things to the engine management.
1st thing would be to give the battery a good charging and see if that changes things.

 

[NorthernDave]

Where do you fill up?
My car developed a really lumpy tickover after switching to filling up at Morrisons - a fuel treatment and a tank of Shell's finest sorted it.

 

[Nigeyy]

I'll second the idea of a fuel system cleaner first -it's cheap and sometimes effective. Are there any warning lights? If so a quick read using an OBD scanner could be fruitful and may indicate which fuel injector is faulty, which sensor, etc....

It could be a gummed up fuel filter (see fuel system cleaner), or even bad petrol, in which case all will be fine after you get some new petrol. It could also be a vacuum leak... Probably not an air filter, but could be worth a punt and again, it's cheap and you really want your engine to breathe properly. Also could be a fouled up spark plug, or even a bad lead shorting....

Based on increasing expense and assuming you don't have any warning lights,

EDIT: i. unlikely I think, but check to make sure your battery is well connected and not loose
ii. fuel injector cleaner
iii. new air filter
iv. new spark plugs*
v. new spark plug leads*


*though misfiring cylinders should show up on an OBD reader.

After that, it will start getting more expensive -e.g. sensors or coils, and you really need more information to narrow it down such a code reader. Then again, it could be some contaminated petrol! (best case scenario). I'm sure there could be other things, but I think these are the more likely ones to start with.

 

[tom73]

We had a sort of some problem. Start with the simple stuff you can do before you need to go down the garage route.
Try the fuel system cleaner it's simple enough to do and may well sort it. Even if not it won't do any harm.
I too would check the battery health and the connections when our last car had an issue it turned out that the garage had left connections loose. Even if they look ok even a little bit loose is enough to make it hit or miss.
The car before it ended up being a fault in the engine management box of tricks lucky that was under warranty.

 

[Levo-Lon]

Defective spark plug or coil pack, whichever is fitted?

Id go with coil pack on its way out, plug or maybe a sensor? Cam or crank.
Unless its showing a fault it might take some finding.

Whats the cold start like? Good or lumpy

 

[screenman]

47 years of motor trade experience tells me to bang it on a tester first, plenty of guys even doing it mobile for not a lot.

 

[Dave7]

Do not clean the spark plugs, do not 'adjust' the gaps! Modern spark plugs don't necessarily like it.

My initial hunch is close to @TissoT's suggestion and I think you should check the battery condition. Is your car still on the original battery? As the battery starts to die the drops in voltage at idle can do really odd things to the engine management.
1st thing would be to give the battery a good charging and see if that changes things.

Thanks
New battery 2 months ago.
As I say, I gave it a good 20 mile run up the motorway but it made no difference.

 

[Dave7]

47 years of motor trade experience tells me to bang it on a tester first, plenty of guys even doing it mobile for not a lot.

When you say "on a tester" is that different/better than a diagnostic check ?

 

[Dave7]

Id go with coil pack on its way out, plug or maybe a sensor? Cam or crank.
Unless its showing a fault it might take some finding.

Whats the cold start like? Good or lumpy

No warning light showing.
Starts first time, even in the cold.

 

[Dave7]

I'll second the idea of a fuel system cleaner first -it's cheap and sometimes effective. Are there any warning lights? If so a quick read using an OBD scanner could be fruitful and may indicate which fuel injector is faulty, which sensor, etc....

It could be a gummed up fuel filter (see fuel system cleaner), or even bad petrol, in which case all will be fine after you get some new petrol. It could also be a vacuum leak... Probably not an air filter, but could be worth a punt and again, it's cheap and you really want your engine to breathe properly. Also could be a fouled up spark plug, or even a bad lead shorting....

Based on increasing expense and assuming you don't have any warning lights,

EDIT: i. unlikely I think, but check to make sure your battery is well connected and not loose
ii. fuel injector cleaner
iii. new air filter
iv. new spark plugs*
v. new spark plug leads*


*though misfiring cylinders should show up on an OBD reader.

After that, it will start getting more expensive -e.g. sensors or coils, and you really need more information to narrow it down such a code reader. Then again, it could be some contaminated petrol! (best case scenario). I'm sure there could be other things, but I think these are the more likely ones to start with.

Thanks.
Blinkin eck.....bring back my 1960s mini cooper

 

[Levo-Lon]

No warning light showing.
Starts first time, even in the cold.

Put some quality fuel in it a d maybe a fuel cleaner.

Supermarkets sell cheap fuel so a tank full of shell will work wonders.

I dont use supermarket diesel in my car or van. Its not that great.

 

[Dave7]

Where do you fill up?
My car developed a really lumpy tickover after switching to filling up at Morrisons - a fuel treatment and a tank of Shell's finest sorted it.

Sainsbury's normally.
I will try this fuel cleaner gizmo stuff (once I find out how to do it )

 

[Levo-Lon]

Sainsbury's normally.
I will try this fuel cleaner gizmo stuff (once I find out how to do it )

You simply add it when filling up, pour it down the filler