Misfire when starts

[Jack92]

Hi guys,

Haven't really had a chance to look at the issue yet but when the rocco is started sometimes it decides to misfire and then will run fine afterwards.

its like it running on 3.

first thought from me are the cold start valve as it goes away after its run for about 30 seconds.

Was just wondering if anyone else has any ideas before i start pulling bits apart :)

thanks

[mark1gls]

I guess your car is injection? If so could be leaking injectors, fuel is slowly leaking into the cylinder so the car has to much petrol on start up, you might fine the problem goes away when its really cold. You could try unplugging the 5th injector electrical plug so it does not spray fuel into the engine on start up and see if that helps but you may find you need it working when it gets to the winter, it does not cost anything to try this so give it a go.
When was the car last serviced? HT leads, spark plugs, dissy cap, rotor arm, air filter.... These could also be at fault.
Blocked AAV.
Air leak in one of hoses.
The list goes on.....

[Jack92]

erm not 100% when it was last serviced would have been within 6 months as the previous owner serviced it and said he owned it for 2 months, and ive only had it 2 weeks now.

He did say he unplugged the 5th injector but it didn't make a difference (if i recall correctly)

[Jack92]

HT leads, spark plugs, dissy cap, rotor arm, air filter.... These could also be at fault.
Blocked AAV.
Air leak in one of hoses.
The list goes on.....

As for your list, if it was any of them wouldn't it continually miss fire?
(spark plugs have been changed + filters)

[mark1gls]

Yes proberlly would misfire when driving but these things can be over looked as they are not changed every service so depends when they was last changed pop the dissy cap off and have a look inside to see what it's like in there.
When ever I change my HT leads every 2years you can tell the difference in starting and the car is a little more responsive.
Have a look for any paper work/receipts for any items..

[Jack92]

will do mate thanks, i was planning on changing the HT's anyway as they do look a little rough, was thinking about the blue igniter ones and seeing if that makes a difference

http://www.candrenterprises.co.uk/shop/ ... 992-6.html

[bensspares]

Most misfires on start up are due to leaky injectors. the fuel has leaked into a cylinder/s causing flooding. if a rev of 2 cures it, almost certainly the issue. I would check them as per haynes before spending any money. Note. when the injectors are removed, there is a posibility that the seals will need replacing as they harden with age.

[Jack92]

Most misfires on start up are due to leaky injectors. the fuel has leaked into a cylinder/s causing flooding. if a rev of 2 cures it, almost certainly the issue. I would check them as per haynes before spending any money. Note. when the injectors are removed, there is a posibility that the seals will need replacing as they harden with age.

that exactly what happens. would it be a case of replacing the injectors if that is the case?

thanks

[bensspares]

Yes, replacing the injectors will be the best money you will spend on performance.. The difference will we remarkable.

I bought Bosh from euro carparts, came with all the seals in place Approx £50 each.... Expensive but worth every penny.

[Jack92]

Ok great thanks, I'll ask for a price when I go next

[Jack92]

Went earlier quoted me 31.50 each on my account so not to bad :-)thanks for the advice

[PeteGLi]

It could also be a fuel system pressure problem. You should get the system tested.