After a long-winded diagnostic process, I've replaced the airbox (old one was in 2 bits) tracked down all the air leaks in the system and checked the timing.

Engine still seemed to be running rough, and seemed to be running very rich. I pulled off the black electrical connector on the cold start valve (I think - the extra fuel line going to the device on the left of the engine bay as you look in with the fuel line going to the back of the airbox) and all of a sudden the car is running much better!

So, is the valve the likely culprit, or would the input signal to it be faulty, maybe a temp sender is away or the connection is bad?

All thoughts gratefully received, cheers
Matt

 

What year?

PJC

 

sorry, an 81 3.0 SC Euro
cheers
Matt

 

As always;

1. Check WUR pressures.
2. Set CO with a proper gauge.
3. Post if you still have a problem.