Smiley diesel automatic Engine light lose power

[theretrolad92]

Hi Guys i need some advice and help with my transit 1996 2.5td automatic with lucas pump.

Every now and again the engine management light comes on and the van looses power and slows right down and will not accelerate. The fault normally clears after turning engine on and off, this is inconvenient and being an automatic the gearbox has to be in park to be restarted. The van starts first time and sometimes the light comes on in a few minutes or i can do say 30 mile or more before it comes on. i have done around 800 miles this month with it coming on intermittently but i think its getting more regular.

I have read that timing belt stretch can cause the pump timing to go out so i have checked the timing using the 13mm, 8mm and 6mm pins and they all locate in the holes perfectly. Is there any more checks to be done here or adjustments?

i have tested the turbo actuator with vacuum gauge and this moves nice and smoothly and holds vacuum
when testing the EGR with the vacuum it doesn't hold vacuum and slowly drops off. would this bring a fault on? could a blocked valve cause the problem?
I have not yet tested the waste gate actuator with the vacuum, the rod seems very stiff and i don't think i can move it by hand is this meant to be like this?
the red silicone hoses coupling the turbo intake do not appear to be split and are in good condition.

Any Advice would be greatly appreciated
Mark