T4 'rough idle' to 'stutter' to 'stall'

[OttoT4]

My '96 petrol T4 has just started to play up big time for me!
When the van is started it generally runs as it should, but occasionally when it starts you can feel that it isn't idling correctly and feels a little out of time so to speak. HOWEVER, when the van has been driven say, 5 minutes of regular driving, when stopped at an intersection, etc, where it's in neutral/ the clutch is pushed in, it will idle correctly, then start to run rough before correcting itself, and almost immediately following it will drop its revs right to the very brink of stalling (oil and battery lights come on) before kicking itself back into normal idling until the cycle repeats!
It's now got to the point that itWILL stall if I don't catch the revs before they drop with a little push on the accelerator.

PLEASE HELP

[Kiels3927]

I had the same problem myself back when I had one.

It turned out that one of the (air?) sensors was belly up & didn't show up on the diagnostics. Forget which it was, but the foreman at Western Star trucks, Rocklea (which serviced VW commercials at the time) picked it.

[OttoT4]

Yeah gotcha, do you have any idea what sensor?
I ended up getting a call-out mechanic today and he said there's no way to fiddle with the idle on the T4 because it's all controlled by the computer, which apparently can't tell you if it itself is faulting? Spending 3k on fixing the computer system isn't ideal if it turns out it's just an air sensor...

[Kiels3927]

Hate ti say it this way but it was one that the mechanic could pull out leaning over the front of the van. Maybe lowish driver's side?

[Seano]

mass air sensor on the intake after the air filter?

[OttoT4]

That's what I thought it might have been, I gave it a quick research and the only thing that turned up was about diesel T4's?
Might have to have another look when I'm a little less tired 😅

[jets]

If you end up not getting the correct answer on this forum you could try the Vortex forum. Although most posters are from the Americans there are some on there that have experience with your engine. The Eurovan, same as the T4, was sold over there with almost the same engine.
Vans and Transporters - all years

[LogicprObe]

Does it do this when it is raining only or all the time?

[OttoT4]

It was doing it all the time, but it's fixed now! Went out on a limb and went to a wreckers and found a 'new' mass air flow sensor in decent condition and swapped it over, when I had a look at mine it was buggered to say the least! The wire was flapping about unconnected to one side of the sensor
Thanks heaps guys!