My 2.8 has been running a bit oddly lately, when ticking over kept surging up and down and when pulling off faltering before it starts to pull cleanly, checked for air leaks, but all seemed fine.then decided to have a look at the idle control valve, bit of a bugga to get off, it was quite dirty, a good clean out with carb cleaner and refit,i thought it would then run better, was not that simple, car ran exactly the same, next i took off the throttle body,and found my problem, the seal from the throttle body to the manifold was knackered, being a sunday and needing the car monday, i made a card gasket, put a coat of gasket seal on it and put it all back together, tried the car and sorted, back to its sweet self, just got to get the correct seal now and fit that