3.9efi poor starting and holding back at 3000rpm

Hi
I have a T25 camper with a 3.9efi. Up until 6 months ago its been as good as gold but has now developed 2 problems.
1 often wont start unless I apply 12V across coil or it fires as the cranking is released.
2 when accelerating once 3000rpm is hit the engine will hold back (like a rev limit) with some spitting sounds out the exhaust.
Could this be a common issue like maybe ignition amp?

Thanks

James

Iggy amp is the most common cause of 'issues on the 3.9....failing that, check the dizzy advance/retard diaphram, the bob weights and the reluctor gap to the pick up....and go from there!

Some motor factors can test the iggy amp - one local to me will test it and if it is faulty, the test is free as long as you buy a new amp from them, else it is a fiver for the test!

Sounds like duff mechanical advance