This might be a long one, so please bear with me...
Anyway, I'm in no way new to VW nor TD's. Some four years ago, our last Quantum TD was sold, eventhough up untill a few moths ago I drove a Volvo 965 with a D24TIC, rebuilt with Kolbenschmidt and Victor Reinz goodies, boosting 2bar, gov-mod spinning it up to 6k rpm, etc, among other gasser cars.
Anyway, Volvo's been sitting for months, engine swap (BMW 2.5-24v+T) ran out of budget, sold most of my other gassers and I was looking for something cheap, fuel-economical (fuel prices in Europe skyrocketing...) and reliable. Narrowed it down to a QSW turbodiesel.
I found one from 1987 (last year here, I believe there were some early 1988 cars, but not sure is it production or first registration date) dirt-cheap and with taxes, insurance, registration, etc until July about a month ago within 100 miles. I bought it off of a farmer, that used it to haul sheeps, pigs and related stuff around, so condition could be described as "gone but not too far" - paint is shot, but nothing crucial and structural rusted out, albeit there is rust on doors, floor, under the rear bumper, etc. Springs and shocks new, top bearings shot; no lights were working; air filter new, oil ages old and gunky.
That was a month and a half ago. Meanwhile, i fixed bits and pieces all over the car, made it less scary and grown to like it and decided to keep it for years. Some time ago, I changed timing belt that was just about to snap and tensioner (Bosch and iPd respectively) and last sunday blue smoke blew out at highway, I coasted to the first pump, left it to cool down, topped the oil up (a bit over a liter was missing), and checked the turbo - shaft play was about 0.4 of an inch - shot. Yesterday I put another pretty good Garrett T3 (shot one was also a Garrett, initially I got a K24, but it turned out to be too seized to bring it back to life), and apart from less smoke, everything seems the same.
So...engine is a CY code - "bigger" turbos (K24 or T3, as opposed to K14 and T2), LDA pump, 51kW (70hp), non-intercooled, hydraulic lifter head. 4-speed tranny to that, 5spd swap being one more thing on the to-do ASAP list, would have gotten it these days if turbo didn't die on me.
It has the oil baffle/cover on the camshaft, but smokes white with filler cap removed nevertheless, regardless is it hot or cold. It has cable-operated mechanical advance that didn't seem to work, then when I changed the belt along with the glow-plugs (2 were shot) since it was hard to start in the morning or when left for some time parked uphill - solved that with a new filter and one-way valve inline before the filter, so I took the pump of when I was changing belt, to access first three glowplugs easier. When i put it back, I did aling crank and cam, but it was late in the night and I was really exhausted, so I didn't realize pump was off some 2-3 teeth counter-clockwise. It did start somehow and drive more-or less ok, but something clearly wasn't right. Realized the mistake the next day and fixed it. However, that night and the following morning, I could really hear the difference with the advance lever pulled out. Now, when the pump is timed as it should, pulling the advance lever again seems to do nothing. Any ideas on that?
Another thing...everything was more or less smooth before the belt/plugs change, but now it seems like it trips somewhere in the rev-range, perhaps around 1500rpm (old Motometer gauges had only clock, got a VDO gasser unit with 7k tach and digital clock but didn't get around of re-soldering it to diesel aplication, so no tach yet. If anyone has the diagram, please point me towards it...), it loses power for a split second and than continues as it should. Also, sometimes it seems to lose power for some seconds, than has too-much power, than back to normal. Anywhere in the range.
Perhaps the pump is full of soot? Or?
Maybe it has something to do with the fact that, when I was taking the pump pulley off, it would't budge, so I pounded a bit on it...once, mallet slipped and hit the shaft. Could I have killed the pump?
Also...the PO had the car for 5 years and never changed injectors. I know that they could be doing funky things, but this does seem too much even for them. Nevertheless, I got a set of NOS Bosch DNO SD193 nozzles on the way, should be here during the week.
Last night, while testing the new turbo I realized if I let it sit in neutral and rev it up to around 2k, it stays there for about 3-4 seconds before dropping. Once, it stood there for over 10 seconds, so I shut it off with the key. Seems a bit like a runaway, but isn't as it can be killed with the key or brought down by selecting a gear and letting clutch a bit, happens only when hot, only in neutral - no "cruise control" situation when in gear. Mysterious partial-runaway, or something to do with the soot inside the pump, or pounding on it? Give me your ideas...
Pump was never tampered with, I myself broke the collar on the fuel screw and turned it in about half a turn, while I had trouble starting in the morning. Brought the idle up about 100rpm and doesn't produce any black smoke, so I don't believe that hang could be related to excessive fuel... My Volvo's D24TIC had pump tampered with way, way more, blew clouds of black smoke at times, depending on the pump settings, but never had rpm hang happen, so I'd rule that out. Will turn it back out that half of the turn anyway and see what happens but I don't expect it to fix the hanging.
Anyway, what started it all was the fact that factory boost setting should be somewhere between 0.6 and 0.9bar, IIRC. However, old, tired Garett was never pushing more than 0.2bar... Then, after it broke and developed huge shaft play, I managed to boost it all the way (lol) to 0.49-ish bar. But not every time... Combustion related?
I expected the second turbo to fix that but...no! Same 0.2 with 0.3bar spikes. Of course, measured in high gear, under load...measured however, never gets past 0.3bar. I have boost gauge connected all the time and ocasionally step on it and watch it with hope, but nothing.
Thought it could be wastegate, so I unhooked wastegate hoses, but to no avail. Still 0.3bar tops. Manifold pop-off thing I have blocked shut, so it's not that as well.
Since wastegate isn't it, manifold pop-off isn't it, only thing that could be is - not enough fuel. But with fuelling already above factory threshold, how can it be?
I hope I didn't bore you all to death with too many details, but I tried not to miss or skip anything. Many questions as well... I'm working alone on the car and believe to be knowledgeable enough, and am not looking for a magic fix, rather some ideas to bounce, other perspectives, since at the moment I'm at the point where I would start throwing random parts at the engine, and that's not the route I can take at the moment.
Best regards!
Topic: Quantum of troubles... (Read 3566 times)
