Been troubleshooting the van and been through most of the suggestions. Today I took it for SMOG. It passed. The tester noted it would "die" and then recover. It did this real bad when I started it this morning, but on the way home it was fine. Guess warming up helps. it was still doing the jerking under load thing though. The tester suggested swapping out the computer and I might try that if I can get one. I see a 90 B250 in a local pick a part, so I might go down there.
injectors - i watched them with the car running and the air filter off. They were quite noisy but they were throwing fuel consistently onto the butterflys, even when the engine died
computer - as above. All the connectors were cleaned and looked very clean even before
sensor cleaning -I removed and cleaned with the deox stuff, every connector I could find
engine computer ground at coil to intake manifold connection - still to check but the coil was replaced so this should have been tightened up and messed with recently
battery to engine ground - deoxed and tightened up
ground to frame? - yet to do, i will put a jumper cable between batter and frame and see how that goes
fuel pump - was replaced
fuel pressure regulator - was replaced
battery cabling and battery itself looks good. Battery was replaced recently
ballast resistor - cannot be located.Here is where it should be but there is nothing there not space for it. Maybe my model doesn't have one?
vacuum hoses - I checked them all again, all looks fine
inlet manifold vacuum - even with the 2 little pipes that go to the flying saucer thing in the air cleaner open, the vacuum held at about 23 units of whatever it is, it seemed pretty consistent. When the engine tried to stall the vacuum would drop, it wasn't immediately clear if that was cause or symptom but nothing happened to suggest cause.
heat riser tube - fine
choke kick solenoid - to do
crankcase breather filter - was replaced
exhaust - looks in great shape; California car
throttle kick down- i checked it all and it is clean and slides just fine. At idle when the engine was dying it didn't move.
I'm leaning to wards this being an electrical issue. The fuel system was virtually all replaced. When the die/surge at idle happened before I replaced the o2 sensor and it went away. Not sure why a two year old o2 sensor who chew itself up, but I ordered a new one. The one in there was 10 dollars, I've gone for a better brand this time @30 something
Open to further suggestions!
As I'm not getting anywhere I have booked this into the local auto shop for a diagnosis on Monday. Maybe I can figure it out by then, in which case i will cancel, but if they find what's wrong and it costs be two hrs of labour I will be cool with that. Even though someone else working on my vehicles where I have failed goes against everything I stand for, I've tried!