Hydraulic KSB.

[Baxter]

I took a AAZ.
I stuck it in my T3.
It's ace.
Anyway, my pump has a hydraulic KSB.
If I connect it, it starts on the botton, runs well.
If I leave it disconnnected, it a *** to start and runs lumpy.
If I connect it to the glow plugs, it starts fine but then runs lumpy after a few seconds from cold.
The pump is new, as is the engine.
Now, to me, the simple thing would be to just leave is connected, but I don't know enough about it as to decide what to do as this thing has a bearing on COI.
The only other issue I have is that it always starts from cold, but warm and hot starts I have to crank it for a while, usually starts when I pull the lever.
I've not had time to check the timing yet, been too busy getting the thing roadworth after being laid up since last September.
just thought I would do some thinking out loud and see if anyone comes up with owt before I waste a load of time I don't have researching it!

[Vincent Waldon]

The Bosch Yellowjackets are pretty sparse in the details about the KSB, probably because it's up to the platform maker (in this case VW) to decide how to implement, and it becomes engineers talking to engineers about the proprietary details.

All of the research I've been able to dig up on the interweb, and some conversations I've had directly with guys with Bosch training, say to leave it connected at all times.... ie bridge it with the stop solenoid and be done with it.  The pump specs assume that it's activated (the engine control module leaves it activated most of the time and de-activates it for specific emission control situations) and most engines seem to prefer it on... yours would appear to be one of them.

[Baxter]

I have the yellow jacket and as you state its not much use!
I just thought it may be related to my poor warm start issue.
It did run fine with it connected.
I'll get to checking the pump timing when I get a minute.
Egt's are a lot lower with it disconnected tho.