VL missing on cold starts

[tomfrh]

Hi,

I have a stock VL auto. It is misses once every few seconds for a few minutes during initial warmup. It only misses at low RPM. Once warm it drives great. It will only miss during the day's first warmup.

It has done this for a couple of days now.

Plugs/leads etc were done maybe 1000kms ago, well before this problem started.

All the sensors are connected and look ok, and the ECU doesnt display any fault codes.

Do you guys have any idea what might cause a problem like this? Any sensors in particular that could be failing? Cold start equipment etc?

Thanks,
Tom

[SNY.3LT]

im not too sure about this someone else might be able to offer a bit more help but there is a sensor near the top radiator hose... its a wire plug and it pulls accross, usually black in color its tiny but that tells your ecu what the coolant is doing.

during warm up the vl ecu tells the computer to run a (richer???) different fuel air mixture im pretty sure this is done to try and eliminate the cold start problem.

This sensor usually becomes corroded and a small file or anything to get it looking shiny again usually does help... ive heard of this sensor also adding to poor fuel economy.

or

your afm could be starting to play up and these could be the early warning signs... or a fouled plug... or check all your leads and make sure they are sitting on properly becuase i had a problem with a lead that got hot and worked its way off the dizzy just slightly but enough to have intermittent contact

[RankONE]

true!! my vl does the same thing but never really worried about it.Is it something i should get fixed, did any1 figure out what it is?? and how do i check the ECU for fault codes? any advice would be greatly appreciated!

[seventh path]

i agree with SNY.3LT....it prob the coolant temp sensor.....they make the car run richer when the engine is cold and they can also add to poor fuel economy.....make sure the plug is on and not deteriated and try getting a wire brush on the brass section...if that doesn't work then a new one is fairly cheap from memory...

[VL Berlina 5speed]

i read some where (think gergorys manual) that on cold mornings ur spos2 slowly pump the accelrator down then bak up slowy once, then start the car, it said 2 do this for cold starts,
but i though a vl is efi so wouldnt this have no affect because its all electroniclay conyroled un like a carby where it would prime it,

this missin ur on about happned in my old car a 5spd vl in the mornuing it missed till it got warm BUT that car got written off and i got the motor and trans transferd in to my currnt vl and it dosent do it any more so im thinking its not a motor problem, could b coolant temp sensor or afm (highly dout it thought)

[BigDaz]

i think most older cars will have a similar problem, just the fact that they are old. Parts get cold and seize up a little, im sure a full re-build with brand spankin new parts would fix ur problem but who's gunna do that ...

[VL Berlina 5speed]

i would

give me a nice cheque and ill do it defantly