Vauxhall Dash warning light

Astra N reg 1400cc petrol
Hi, just wondering if you can help a light appeared on my friends dash
oday - then the car started to run rough - so he stopped the car for ten
minuites and then started on his journey - the light stayed off for a couple
of miles and then came on again and the car started to run rough again. Once
he got home and left it for a couple of hours the light is now not on and
the cars running fine any ideas.

Bill

 

blimey, gives us a few good clues won't you!
if it's the engine management light then i would suspect the on-board pc
(emu)
is detecting a fault somewhere & is (switching) going into 'get you home'
mode
the car wants a looking at.

if it's any other light, then who knows?

mike

 

Hi Mike
its all I got from my friend, from what my friend explained its the engine
management light though
what does the engine mangement light look like? is it a picture of an
engine! I drive a peugeot.

Bill

 

Usually the light is orange with a lightning streak through it, whereas the
Peugeot has a letter K.
The codes need pulling to find which sensor is on the way out.

 

Try spraying some carb cleaner down the MAF before paying out for any
diagnostic test.

 

Is it a single, or multi point injection system?

 

single

 

That rules out the air mass meter, because the cpi doesn't have one; it
relies on MAP sensor technology. It would be worth checking to see if the
vacuum pipe to the MAP is clear and that there aren't any cracks in it.
Is the fault evident all of the time, or does it come and go? If it's the
latter, it will most likely be a sensor on the blink...possibly the MAP
(manifold absolute pressure).
The MAP sensor is an analogue variety, and if you have a dvom, I can post
the test procedure.