Fitian, I think I know what your problem is now. This morning I installed the original Delphi cartridge that came with my new CAV when I broke the glass on my original one. After 30 km or so, I began experiencing the same symptoms as you did with the car losing power, and I had to switch over to diesel for the rest of my journey home from Newcastle to Maitland. As you know, I have a heater in front of my lift pump as well, which boosts my oil temp to 100degC. While on the way home, I had two more attempts at running on Veg, and on each occasion the 300D started to stutter, so I had to switch to diesel quickly.

I know that the system was primed OK, as I have done the routine many times before, and my trip down to N/C on veg was quite normal. I'm almost positive now that it is the Delphi cartridge that is the culprit.

I've just opened up the Delphi. As expected there was no plugging of the paper element (it was NEW). However, one thing was obvious, the element was holding a lot of oil - much more than I noticed when I pulled the Fleetguard one apart.

What I think is happening is that the heat affects the Delphi's paper element in some way which causes it to swell and block the passage of the oil, thus causing fuel starvation. When you added biodiesel, it thinned the oil enough that it was able to pass through the filter OK, so your car then ran without a problem.

Try another brand of filter cartridge, as I'm 90% certain now that it is the Delphi causing the problem. I'll be 100% certain on Monday once I've travelled to and from work without problems using a Fleetguard cartridge.

If anyone is using the Delphi CAV filter housing, what brand of filter cartridge are you using successfully?

__________________
Cheers
Bruce
http://oztayls.blogspot.com/

1976 W123 300D (3 litre 5-cyl NA diesel running on SVO since June 2006)
1982 W126 280SE (Sadly is For Sale)
1993 W124 300D (3 litre 6-cyl NA diesel - being converted to SVO)