Intro...first Benz, advice - PeachParts Mercedes-Benz Forum

sikbrik · #1 10-22-2003, 02:16 PM

Hello Everyone,

I stumbled across this board and I'm so thankful for it! Many of you seem to really know these vehicles! I'm an ex-mechanic with most of my experience in newer EFI compact vehicles and classic domestics. I haven't tinkered with MB's at all.

I just purchased a 1976 280C automatic. Is there anything in particular I should look for when I go over the car? It was a steal and it runs so I bought it without much regard for what will need to be done.

For now it will just be a fun driver to cruise to work in every now and then. I manage car shows for a living so having a somewhat "different" car has always appealed to me. Ideally in the future, I'd like to convert the carb to injection. I'm not sure if the best way to go is to retrofit factory mechanical injection or to go with aftermarket EFI. I'm sure that's all dependent on what I want from it...a factory look/serviceability vs. ease of tuning/efficiency.

Are there any other useful resources to read in addition to this board? Thanks in advance for any tips you can offer! I look forward to being a contributing member of this community!

Regards,
Mike Kelsch

sikbrik · #2 10-22-2003, 08:16 PM

That's what I'll do. I appreciate the tips. I'll be driving it stock for a while.

As far as aftermarket FI, I planned on using an existing stand-alone system I have with a "homemade" fabricated intake. That makes it easy!

psfred · #3 10-22-2003, 08:36 PM

Check the condition of the windshield gaskets and replace if hard -- otherwise you will flood the car every time it rains and the floor will rust out. Repairable, but a HUGE pain.

Other than that, just the usual old car stuff -- expect all the rubber (front subframe mounts, rear subframe mounts, support for the driveshaft center bearing, door gaskets, etc) to be dead or dying.

Keep the area behind the headlight buckets scrupuluously clean, this is a serious rustout point if you let dirt collect there, there is no inner fender.

If you have leather upholstery, get some Leatherique and treat it well before it rots away!

I love the W114 chassis!

If you have carb troubles, a Holley spreadbore will make a VERY nice replacement. I've never been all the fond of Quadrajets -- they work fine when you finally get them set up correctly, but they are a huge pain, and a Holley of the same size will use less fuel every time. I've been intending to look up the correct size for the Holley -- my brother has a book with the sizing charts. Get one with vacuum secondaries.

K-jet fuel injection off a later M110 engine requires the manifold with cold start valve and fuel distributor, the idle control and cold enrichment valves, and the fuel pump with tubing (the hoses from the carb engine won'd hold the pressure). All the fittings install easily -- you must remove a couple plugs on the block. No computer before 1980.

Peter

ctaylor738 · #4 10-22-2003, 08:36 PM

To my knowledge, there is no aftermarket FI for this car.

Probably the best course if you are really determined is to get an entire car with Bosch K-Jet injection (280E, 280CE, 280SE) to get all the pieces (fuel system, computer, relays, wiring, head, air cleaner, etc.).

For a lot less money and trouble, you can convert to a Weber or Holly (Quadrajet) carb.

Otherwise, make sure that valves are adjusted, clean the points and check the dwell once a month. Make sure that the choke gap is right. Clean the crankcase ventilation valve. Enjoy!

sikbrik · #5 10-22-2003, 09:17 PM

Thanks psfred...quite an informative post.

I've just looked under the car and the drivers side floor is rotting up front, almost into the firewall (or bulkhead...whichever is the right term).

I guess I'll be spending the weekend doing a search for water leaks on this forum as well as tearing out the interior to see where the water is sitting. I did read a few posts about replacing floor pans already. Sounds like a chore. I've helped do this on a full frame car but never a unibody.

I'll also be looking at replacing the window gaskets/seals. Is there a preferred source for these parts?

I just hope the interior rockers aren't beyond repair!!! I'm sure you'll all be hearing a lot from me now!

Oh yeah, I'll search through the forums for all of the details but if somebody knows off the top of their head...is the Holley spreadbore a bolt-on affair or does somebody make a kit?

Thanks again.
Mike

neileg · #6 10-23-2003, 10:42 AM

You should look for rust here:
- The seam between the floor and the inner rocker panels
- The floor where you have found it
- The outer rockers
- Under the bottoms of the front fenders where the extended rocker makes a wonderful mud trap
- Door bottoms
- Top of the inner fenders (if that's what they are called in the US) under the hood shut panels
- Nasty place round the back of the windscreen wiper motor
- Trunk floor
- The valence under the front bumper
- The bottoms of the rear fenders behind the wheel

Guess how I know....

#7 10-23-2003, 01:56 PM

$20 paperback which combines a history of the cars with what to look for good / bad in most models. Think he had good things to say about the cute coupes. You'll learn a lot in a well organized format.

psfred · #8 10-23-2003, 07:34 PM

Complete floor pans are available, I believe, and this is the way to go. You will need to completely strip the car (sigh), but you can then cut out the old ones and weld the new ones in place. Factory look, all the bolt holes will be correct, and you won't end up chasing rust pockets like my brother and I did. Given the time and effort we spent, next resoration gets new floorpans, period, no patching!

Fenders are also available, as are repair sheetmetal for the rears. Not a terrible car to restore, just time consuming.

The Holley will fit after you enlongate the mount holes a bit. Air cleaner won't, you will have to manufacture an adapter or adapt another air cleaner housing somehow. Quadrajet will be similar, although I seem to remember that there is one that will drop right on, not sure.

Peter

#9 10-24-2003, 08:23 AM

repair sheet metal...I've been happy with what they supplied for my 123s.

murray720 · #10 10-24-2003, 08:46 PM

psfred,

Quote:

If you have leather upholstery, get some Leatherique and treat it well before it rots away!

Can I use Leatherique on the MB Tex upholstrey? I imagine I can but just thought to ask.

thanks,
mur-dawg

sikbrik · #11 10-24-2003, 10:02 PM

the floors weren't as bad as I had imagined...but there were many "small" holes. I found the source of the water leaks...the grommets in the firewall were disintegrated and the holes began to rust leaving large entry ways for water. It was pooling in the car and creating the rust.

Spent the day with small "patches" of sheetmetal, some spot welds, some fiberglass, and some reinforced resin...oh, and some rubberized undercoating and silicone to fix the holes where the grommets were. Also used "flowable silicone" to seal the old windshield and backlite gaskets. I'll fix all of this the right way someday but I wanted to get it patched up to get inspected before winter. I did source full floor pans for both sides for $100 each. I'll probably order them now so I don't get too happy with my quick repairs.

The best news is that I got into the car a little bit mechanically and it's already got what appears to be the JAM Holley conversion. Many of the transmission linkages were unhooked but all in good order so I simply reconnected them and adjusted the carb to the best of my ability and everything seems to be running well. A tune up and oil change tomorrow and we'll be ready for state inspection!

Other notable items:
-Original Becker radio is there but not operating (no power.)
-Original antenna is there but not operating (again, no power.)
-A/C was converted to R134A and blows cold.
-Heater control valve is siezed.
-Cruise control is all there but not hooked to throttle...missing tiny grommet at linkage.
-Carpet was trashed from the water. Rest of Tex interior looks great. All seat supports are very solid. Wood trim finish (urethane?) is cracking.
-Speedometer and odometer not operating...I'll assume it's just a cable.

-There is a blue vacuum line running along the driver's side under the stainless trim. It runs toward the trunk. Whatever it was hooked to has a nipple broken off so now it's just sitting there hooked to nothing. I thought maybe the antenna motor but does that run off of vacuum??? Anybody know what this is off the top of their head?

Oh, and the cockroaches living in the rusted out sections of the unibody left once I pounded & shaped sheetmetal against them and they smelled the fiberglass resin!

I still have MANY questions and I'll be watching this forum closer than I watch the Brickboard (have to keep my Volvo running, too, after all.) Thanks for all of the help.

Regards,
Mike

1976 280C - not a leaker anymore!

psfred · #12 10-24-2003, 10:14 PM

Do the seat back catches work properly (that is, seats locked with doors closed, unlocked with door open?

If not, that vac line is probably for the vacuum servos for the seat backs. Otherwise, I don't know what blue would be for unless this is a replacement line. Normal routing for the trunk and gas filler lock hoses is down the passenger side.

Proper tunning for idle mixture on a Holley is to open idle mixture screws till you get max rpm, then slowly close til the rpm drops by 50 rpm. Then close 1/8 turn more. Or use an exhaust gas analyser (you have one in your back pocket, right?).

Leatherique makes a product for vinyl. Using the leather stuff probably won't hurt, but it will also do nothing, it's emulsified oils to soften and re-oil the leather, and they won't penetrate into the vinyl.

Peter

Catrinus · #13 10-25-2003, 12:22 AM

The blue lines are definitely the vacuum lines for the seat back locks. Mine don't work, either!

Post a picture of your new baby, OK? I think that other than the carb (which you said the prior owner already swapped out) you will enjoy the car a lot. Lousy gas mileage and mediocre power, but style all the way to Sunday (in my humble opinion).

Send me your address (catrinus1@netscape.net) and I'll make you a copy of the dealer service manual on CD-ROM. It's quite good. Why pay $10-40 on eBay when all those are just copies that someone made for $.40 at home. I'll also send you some parts (mechanical and interior) places I've found that have been quite good. Lastly, the moderator of this forum (Chuck Taylor) knows more about these cars than anyone else outside of Germany, I think. Search for some of his postings.

Catrinus
73 280C