The fuel line between the fuel filter and the tank will have a non-return valve to prevent the fuel from running back into the tank when the engine is not in use. If this is faulty then the fuel pump will have a struggle to suck fuel each time it is started.
If the primer fails to firm up it will either be due to an air-leak, fauty non-return valve or the rpimer bulb itself may be porous.
Thanks MadNoel for the explanation.
We will definitely give that a go, but I have to say,
my car was worse than ever today and it wasn't that cold..
6*c at 7am this morning and 9*c when I left work at 1pm.
The car normally starts fine on my return trip from work (16 mile round trip) but today it started, stalled - started up again fine, ran lumpy at idle for 2 minutes .. the throttle worked this time - but when I tried to hold the revs at 11,000 the rev needle jumped up and down 1,000 - 12,000 til the lumpy feel disappeared after 5 mins .. it's the first time it's done that.
The sound isn't something you can hear from the engine itself - it's something you can feel from inside the car -
not massive - but definitely not normal!
How much does the
valve do at start up and idle?
I'm beginning to think it's that.