Re: [MBZ] 1987 300TDT (W124) Climate Control Problems
Steve, Sounds like vacuum pods to me. And it sounds, from memory, like the system may be operating normally with the exception of the center pod. As for the need for the breakout box, I was able to work around it with the test instructions and an inexpensive VOM. For both 123 and 124 models, the instructions include wire harness test points, test mode, and pass/fail parameters. If you need more of a hint, I'll hunt around for my markup, but you should be able to discern which component, associated power supply, ground, or signal wire is being tested in each step, to fault isolate without the breakout box. Mike Boerner 87 300SDL 125kmi 87 300D 130kmi
Re: [MBZ] dieselvolk swarm soybean oil section at Costco today
Chris wrote: "If I buy a million twinkies and feed them to my parakeets, the govt won't give a shit. Just like If I buy 200+ lbs of VO and feed it to my car." I write: Twinkies??? Will our diesels run on twinkies? That'd be great, because there seems to be an inexhaustible supply of twinkies on the planet. For those from the Philadelphia area, TastyKake Krimpets would probably serve as a suitable substitute (if you could wrest them from their owners). Next stop, Krispy Kreme Oel. These half-baked ideas should provide ample fuel for flame throwing, thereby reducing the cost of diesel fuel worldwide! Regards, Mike Boerner 87 300SDL 125K 87 300D 130K
[MBZ] Trigger points
Seems like the FI points themselves didn't fail on my '75 450SEL, but I do remember replacing the wires that went to each set. Probably cleaned the points of pitting as well. The ignition points, on the other hand, burnt up on a daily basis, from crankcase fumes leaking past the distributor shaft seal. Wish I'd been able to figure that out on my own, but my techs kept it a week before getting back to me with the bad news-a $700 distributor back in about 1986. When a catalytic converter (I believe it was ONLY $1200 per side back then!) went while I was still mulling over the distributor shaft seal issue, so did the car. Replaced it with our first diesel 300TD wagon, with nary a problem after. Funny thing was that the 450SEL ran extremely smoothly for the one day or so that it took to foul the ignition points, and reached 20mpg on the road. Once it became clear how unnecessarily mechanical and unreliable the chain of events was to fire a cylinder, it wasn't much of a decision to dump it.
Re: [MBZ] hard to start "cold"
George, I don't remember if there was a thermostat-controlled flap in the air snorkel on your car or not. If so, it may not be open. I agree with Peter that it sounds like a new air filter, but you might be able to verify by reading vacuum from a port above the throttle plates, with air cleaner on and off. Mike Boerner diesels now, 1987s, 300 sdl/d 125/130k
[MBZ] W124 sunroof kaput
Dave, You wrote: "There's a bar that goes across the width, on the rear of the opening... the left side moves back, the right side stays put. Right now it's stuck/jammed in the popped-up state, which I guess is better than wide open, but still doesn't make the car useful in wet weather. If you can remove either the polished track cover (rear three screws on the side that won't move), or the outer roof panel (scribe the bolt head positions first), you'll find the broken pieces of plastic/pot metal obstructing movement of the slide in the track. Remove the pieces and you may be able to close the roof. The manual doesn't provide any instruction at all for this operation, you're sort of on your own. Probably why most folks find it necessary to consult an experienced shop for repair. Mike Boerner 87 300 sdl/d, 125k/130k P.S. If you're Dave Meimann, You can probably do this, as you beat my time replacing the climate control vacuum motors by at least a factor of two, maybe more.
[MBZ] W124 sunroof kaput
Gabriel, Mine went about two years ago, same symptoms. Fixed it myself, but the parts aren't inexpensive. Look at the sunroof R&R procedure in the manual, it'll get you far enough into removal so you can see what's wrong, and how to remove the sunroof. ( This involves popping the sunroof headliner loose at the front with a flat bladed object, and sliding it forward til it's free). IIRC, the failed parts appear to be approximately $5 worth of plastic, namely an item that serves as a ramp for the pop-up feature (probably the angle bracket, although I don't have the parts catalog. You should buy and install both sides at the same time, as you don't want to do this job twice. I think I wound up with a parts cost of $300-$400, from EMB in Fairfax, VA, at good prices. The only problem I had was that one of the parts came fully dressed, i.e., with piece parts attached, and I had ordered the piece parts as well, due to the uncertainty caused by the part number/nomenclature changes associated with the new design. I found I was able to work around the special tool requirement (I believe a screw and wedges served the function), but I also scribed the position of every adjustment bolt to aid in its reassembly/adjustment. Exclusive of awaiting parts time, this repair consumed the better part of an entire day (once you've removed the headliner, you should be able to figure out how to lower the roof-I remember removing the roof panel, removing the broken brackets, then re-inserting the roof panel, shimming at the front sides to match the outside contour, and taping it shut for about a week til I ordered parts). Maybe I'll get it done it in 1/2 the time when my 300 sdl sunroof goes. Maybe not, judging by how little I can recall now! Mike Boerner 87 300sdl, 87 300d, 01 320ml
[MBZ] hard to start "cold"
"How tight should the choke be at that temp? should it be closed all the way(2.4 mm openening)" George, I'm pretty sure there's a specified "choke gap" adjustment. That said, the choke gap clearance depends on the choke heater covers being set at their index marks, the choke actuating rods (tensioned by the choke heater cover) being set correctly (at the rod/setscrew interface at the top of the rod), and the choke vacuum pull-off being set correctly (locknut and set-screw in vicinity of rod). This should only take a week or so to straighten out. Good luck. Mike Boerner 87 300sdl 125K; 87 300d 135k; 01 320ml 38k
Re: [MBZ] No torque (was 72 250 no vacuum advance)
George, There is another ignition failure mode that's intermittent, but I don't think it's your problem. You may want to note it for future reference. High ambient temperature operation, any speed, the engine shuts off, as if you'd turned the key off. Do NOT change the fuel pump first, like I did. The germanium transistor in the Transistorized Switch Unit (TSU) apparently grows faint in the heat (for southern folks here, I guess that means it get "the vapors?" Anyway, it faints, and stops delivering spark until it cools down somewhat. After a lot of unsuccessful troubleshooting attempts, a light wired to the output revealed the problem. The dealer probably would've known about it, as it turns out to be a known weakness with the germanium transistors. Too bad I didn't know about it in 1976. Mike Boerner 87 300sdl 126k, 87 300d 128k, 01 ml320 38k > George, how did the exhaust look? Were you getting any black smoke with > the car under load? I just wonder if your ignition system has troubles > other than spark timing. > Russ
Re: [MBZ] No torque (was 72 250 no vacuum advance)
George, are you certain your float level is set to spec? and that the float valves open and there are no dead spiders in there (don't ask why I would check there, but I found a dead one inside the valve once. sounds like low/no fuel. do the accel pump jets squirt fuel when you open the throttle? also check the clear fuel filter to see if fuel is being moved, and the fuel return valve to make sure it's not stuck open (I think it only opens at idle) Mike Boerner 300SDL 300D, 1970 280S/8 sold in 1985
[MBZ] DIGEST QUOTE APOLOGY
Sorry ladies and gents, either hit a wrong key, or was checking for light leaks through my navel. Mike Boerner 87 300sdl 87 300d
[MBZ] 72 250 no vacuum advance
George, I shifted gears on you here. THIS page 00-7 is in the 250S manual. Sorry "Should I be able to blow compressed air throught them? any easy way to activate? SORRY, SHORT OF TIME TODAY. JOB 00-74/8 SHOULD ANSWER MORE THAN I CAN, IF THE 250S PUB IS CLOSE TO THE SAME. IT LOOKS LIKE PAGE 00-7 TALKS TO MOST OF THIS. THERE DOESN'T APPEAR TO BE A SPEED SWITCH AT ALL. IT LOOKS LIKE ADVANCE IS DEPENDENT ON ACTUATION OF THE 100' THERMOSTATIC SWITCH IN THE THERMOSTAT HOUSING. WHEN GROUNDED (H20 TEMP >= 100C), YOU GET VACUUM ADVANCE. THE ONLY TIME YOU GET RETARD IS AT IDLE WITH THE THROTTLE VALVES CLOSED, CREATING HIGH VACUUM. MY FEELING WAS THAT IF ADVANCE WAS REQUIRED TO PREVENT OVERHEATING, MAYBE IT'S BETTER TO HAVE IT ALL THE TIME. I'LL LEAVE YOU TO PONDER THIS." Mike Boerner 87 300sdl 87 300d 01 320ml
[MBZ] Idle shutoff solenoid
If Rusty or Mercedes can't get it, I'd look at any carbureted VW product of the same era. I think they all had Zeniths and they all had that solenoid. Mike Boerner 87 300D 126k, 87 300SDL 125k, 01 320ML 34k
RE: [MBZ] obscure carb screw
Michael, MY 1970 280S only had one screw. A quick look at the old, ragged, 5% loose-leaf manual indicates that high idle speed is to be adjusted on the FRONT carburetor only, for thermostatic chokes. The spec was 2500-2700 rpm, warm engine, perfect idle (more about that in a sec), vacuum hose for ignitiion changeover removed from distributor (as of US model year 1970). You can only adjust the idle speed with the throttle wide open (to access the screw), so you must stop the engine for each turn of the screw. The book says 1/2 turn of the screw will get you 200-300 rpm (in=higher, out=lower), and says to repeat the check on the other (rear) carb only in case of carbs without thermostatically controlled choke valves. As far as a perfect idle, good luck!!! I found that my Unisyn carb flow meter was close enough, once I got the secondary throttle valves properly adjusted (probably closed), to balance the air intake for front and rear carbs. Irregardless, I found myself partially disassembling one or both carbs at least every couple of months, for a rough idle/idle miss, invariably caused by plugged idle jet (the long tube with an extremely small origice at its bottom). I'm not sure I ever conquered the problem, or identified its true cause. Dirt and an occasional spider would find their way into the float bowl, despite clean fuel and air filters, good gaskets, plastic plugs over the choke linkage,etc. Clearing the idle tube would always return the car to full, smooth power output at idle and off-idle. The only other early maintenance headaches I recall were the exhaust heat valves hanging up, but I believe new thermostatic springs and the right lubricant finally fixed that problem. The factory service manual I have doesn't list 250S, but if you can't find anything else, make me an offer of less than $20, pay for shipping or pick it up in Herndon VA, and it's yours. Or try Rusty for the correct manual. I also have a chassis and or climate manual here as well for 114 and 115 chassis, of the same vintage, but in better shape. Neither of these two factory manuals has seen much use over the last 20 yrs. Mike Boerner 87 300sdl, 87 300d, 01 ml320