idle surge - any help please

[chalkys1966]

ok i have a NF2 windsor 5.0l engine. standard intake - after market headers and exhaust. goes well BUT GRRRRRRRRRR idle surge!

anyone who has had this problem will know what i am on about. the issue is fixing it. ive read all sorts of posts and issues but i finally took it to ford in epping. they have told me after several hours of searching its the fuel pump. i dont believe it !!

the problem is the car will idle surge - sit say at 1000 rpm then drop to 600rpm then back to 1000rpm etc. also its hard to hot start and blows a heap of black smoke when it fires. ive done a few checks myself with voltages and resetting idle. ford did all the tests and found no electronic faults. its not missing or misfiring - apart from this idle surge it goes nicely.
anyway if someone agrees its the pump ill go get one and fit it myself (ford wanted $700). any help out there? ive reposted this as the pub seems to get lots of attention! :

[FordFan86]

Checked all hoses? I had a similar problem, was a small vacuum leak from something to somewhere... put it back on and it settled down.