misfiring, not injectors!!!

Hi, help please

We have a freelander td4 x-reg(2000)
It is misfiring in idle and also sometimes when driving, it has a bit of a wobble in idle.
We were told it was the injectors so bought 4 from the internet.

My hubby has today unplugged the injectors and they all seem to be working(should have done this before we bought the injectors).

Any ideas what it could be ?
thanks

maf sensor, fuel filter, Hole in a vac pipe, Dodgy supermarket fuel

All have been reported for similar problems to this

Try unplugging the maf sensor at the left side of the air filter

Un plugging injectors shouldnt make it fine, Every injector unplugged should make a deterioration in idle, If one doesnt then its faulty

Injector pipes

If he unplugged each injector while the engine was running,(which you shouldnt do anyway)to see if it slowed the engine down - you cannot be sure that you will have the right answer.The only way to diagnose them properly is with Testbook or remove them and have a fuel shop test them.
Try Testbook first,as they are famous for being gits to get out.I made a slide hammer adapter out of an old injector top cap to do it.

thanks, he did pull them out whilst engine was running!! and thats when he thought it may not be an injector.
We are going to a land rover dealer for the diagnostic test before we do anything, we do have a diesel shop that repairs injectors, any idea if they can test them?

We wont know which was is faulty and dont really want to change all four(as if what people are saying they are a mare to get out).
Will a fault with the injectors come up on a diagnostic test?

thanks