[gazw]

Hi people,

I've a P reg corsa b 1.2 trip with 116500 miles on the clock.

The problem I have at the moment is on first start up from cold the engine fires up fine but idles really lumpy like it's running on 2 cylinders for say around 10 to 20 seconds and then just clears and runs and sounds sweet as a nut.
No EML comes on.
Sometimes does the same thing when warm but not all the time but all the time from cold.

Have searched this site and can't really find my problem so hopefully someone out there can help me out please.

Cheers
Gaz

 

[taurus]

Sounds like a lazy plug (or two), or worn HT leads.

Check if it's got the dizzy type of ignition or a DIS module. If it's a dizzy check the 5 cap contacts and rotor arm.

On both kinds check if the HT leads are old - if so replace them.

Check if the plugs are old - and if so replace them as well.

 

[gazw]

Yeah it's got the dizzy type ignition. All the dizzy cover, arm and leads were replaced not to long ago along with the spark plugs.

 

[taurus]

In that case give it all a spray with WD40 in case there's damp getting in there. Have a look at the plugs as well - make sure they are gapped right and aren't fouling.

 

[gazw]

I'll spray with WD40 tomorrow. The spark plugs are gapped right but are really black. I don't do many miles in the car less than 2500 mile a year.

 

[taurus]

The plugs are fouling then - if you only do short journeys that will cause it, or try a new CTS. They can cause an over-rich mix if they begin to fail. Make sure the air filter is clean, and also check the vacuum pipe running to the MAP sensor.

Given the miles you're doing I suspect it's just too many short journeys.

 

[gazw]

i'll have a look at these things tomorrow and let you know how I go. Thanks for your help up to now anyway.

 

[gazw]

Right I've cleaned the spark plugs and re-gapped them. Air filter is brand new and the vacuum pipe for the MAP sensor is fine.
Think i'll try a new coolant temperature sensor like you stated in a previous post.
This CTS in the Haynes manual says it's located on the right hand side of the inlet manifold but I can't find it but there is something sticking out of the left hand side at the rear of the manifold next to the alternator, is this the CTS?

Oh and forgot to mention that it doesn't really like to start when hot. It will start but takes longer than when cold and sounds very lumpy and has cut out recently twice whilst driving.

Oh and for the life of me I can't find the right coolant temperature sensor anywhere only at the main dealers can somebody shed some light on this for me and point me in the right direction.

Cheers
Gaz

 

[taurus]

The Haynes uses 'left' and 'right' to refer to the side of the car facing forwards, whereas we tend to use 'left/right' as we look into the engine bay.

The CTS is down the back of the inlet manifold more or less in front of the driver's position. It's a 19mm spanner to undo it and due to the design you can't use a normal socket on it. I use a 19mm ring spanner sawn in half for them.

You ought to be able to find one from a decent factors without a problem - or give Autovaux a call and tell your reg. no. - they'll send you the right one 01924 376003.

If it's struggling to start hot it's almost certainly a dud CTS and that will foul the plugs.

(You might find the main dealers aren't too bad on price for a CTS - I've got them over the parts counter and not paid over the odds for them)

 

[gav93]

around £16 from vauxhall i bought one the start of this year ive had a few 1.2 8v's and always replace the CTS its really worthwhile improves the running and i notice a huge increase on my MPG around 7 litres(£10 worth) gets me around 50-55 miles which isnt too bad considering most is city driving and a few motorway runs.

they are bullett proof engines but usually previous owners dont take note of some running faults or replace many sensors such as CTs so you should see a dramatic change.

 

[gazw]

Well thanks for all your help. I will get one asap and let you all know hows it's going.

Oh by the way is a water temperature sensor the same as a coolant temperature sensor? It's just that seems to be loads of the water temperature sensors on ebay.

Cheers
Gaz

 

[taurus]

They vary - some cars have three things, a sender for the temp. gauge, the CTS for the ECU mix control, and the thermoswitch to control the radiator fan. The earlier ones tend to have all three. Later ones often use the CTS to cover all three functions.

 

[gazw]

Just an update. Fitted a new CTS the other day and my car is now running sweet as a nut:laugh:

So just a big thank you really to the people on this forum who helped me out.

Cheers
Gaz