"lumpy" Engine

[steve]

I am sure this is a real easy one but now the cold weather is coming my car is a bit "lumpy when its cold. once its heated up it fine.

 

i really noticed it the other day going up a slip road and was trying to accelerate but not much was happening. then all of a sudden it was like a rocket again.

 

any ideas before Lou has a go???

 

cheers

 

steve

[strees]

Is your car parked outside? If so, could be water in the dizzy cap/spark plugs. If so, spray liberally with WD40.

[steve]

It is parked outside but it happens every day and always gets better when its warm.

 

could it still be water in the dist cap?

[strees]

Possibly. Mine did this (and also had a problem accelerating) until the engine had warmed up. I sprayed the HT leads spark plugs and dizzy cap with WD40, which did the trick.

 

Also wondering whether your IACV is dirty or needs resetting, i.e. it is not mixing the fuel/air correctly when cold. Try resetting with the 5 presses of the accelerator trick.

[steve]

Oops - you lost me there!

 

IACV? 5 presses of the accelerator? I'll do it... but what am i doing????

 

I'll also give the HT leads and dist cap a spray of WD40 as you suggest. (i understand that one!)

 

thanks

 

steve

[Bramble111s]

Since its been cold, sometimes my revs start at a flickering 1000, only after its warmed up do they settle back to the 900 mark. But I would guess this would be a similar problem?

 

I haven't tried hard acceleration, as I am on the commute and would be up the backside of the car in front.

 

This might be the best place to warm up any cold knobs?

Is this too far??

[Mark H]

Sounds like damp as strees mentioned.

[strees]

Steve,

 

To reset the IACV (Idle Air Control Valve):-

1. Switch ignition on(all lights on dash lit)

2. Make sure immobiliser is not on

3. 5 slow full presses on the accelerator

4. start engine. Some people say to then switch ignition off, but I have always been told to start.

 

I do however believe it is damp related.

 

You can also by ignition sealant spray from Halfords which might do a better job than WD40, but as I already had it in the stable I used WD40 and it worked.

 

Cheers

 

Simon

[steve]

Thanks for that, i'll give it a try!

 

Steve

[Bramble111s]

Steve,

Sorry for my unhelpful reply.

My car really does flicker in revs, although this would seem like a normal thing to do in the cold?

Very interesting to hear about the idle air reset,

will be curious to find out if it helps.

[steve]

I've reset the IACV (ooh, look at me - i know what i'm talking about now! ) but the weather hasnt been so cold recently so i dont know if its had any effect.

 

I'll keep you posted though!

 

Thanks again guys!

 

steve