1980 350sl

[bwheitman]

Friends,
I bid and won a 1980 350SL for 2k. The title is lost and it doesn't run, but hey, I need something to do during the winter months.

The seller has told me that the engine will start if he pours fuel down the throught, but just temp, so the fuel system is defective, probably because it has been sitting for 4 years. What kind of issue can I expect with this fuel system? What kind is it and is it mechanical or electronic distribution?

I can not find any reference to a 1980 350sl, is this car for real? has it been misbadged? The pics show a V8, it has 57k on the odometer. (Who knows)

I may have just bought a car for parts, or I may have just got something fun to play with. I am going to have to rent a space for it since I can't keep my SL320 outside. I am going to pick it up in Houston on Saturday.

Any advice would be appreciated from the forum. Thanks again for this valueable resource and all your help, it makes owning an MB more enjoyable to know there are others like me out there!
Regards,
Brian

[Robert Mowbray]

Good luck with the car. It is most likely a 450sl, that's what mine is. You might want to do a search of the site for fuel injection for answers to your questions. I've never worked on mine.

[maheath]

There was a "euro" 350SL in 1980. It's a Continuous Injection System (CIS), i.e. mechanical. K-jetronic fuel injection. The engine is the M116.984. The 3.5L M116 engine with K-Jetronic fuel injection was never sold in a U.S. model Mercedes. That basically means that getting accurate information on it here in the U.S. will be like pulling teeth. In fact, the last 3.5L M116 sold in a U.S. model was in the 1971 280SE 3.5 and 300SEL 3.5. I'm not even sure if those were fuel injected or not. I don't think they were.

If you need to fool with the fuel injection at all, I would recommend the book Bosch Fuel Injection and Engine Management, by Charles Probst. You can find it on amazon.com for about $21 new.

If it's been sitting for four years, you will need to go completely through the fuel delivery and injection system. Whatever gas is currently in it, get rid of it. You may even want to get the tank professionally cleaned. Start at the tank and go forward. Check the hoses for cracks, see if the fuel pump is getting power, replace the fuel filter, etc. The book has an excellent troubleshooting section. You'll need a CIS-specific fuel pressure gauge. There are a few out there, I got mine at J.C. Whitney.

Based on your description, my guess would be the fuel pump or the fuel distributor. Pray to God it's the pump. The cost of a new fuel distributor would be about as much as you paid for the car. And it's not like there's a bunch of used ones laying around. If it comes to that, look for a 1976-1980 350SL, 350SE, or 350SEL. All are euro models.

I don't mean this to sound condescending, but how do you pay $2000 for a car that you know nothing about, haven't seen, and didn't do any homework on?

[bwheitman]

Mike,
Thanks for the information. I have not seen the car, but I am driving to Houston in the AM to look at it, and if it is a rust bucket, I just won't get it. I have been wanting an older SL to tinker with and this one was just so cheap I couldn't pass it up. There were only pictures of the car and a discription and as long as the seller is being honest about his description I should be ok. If he is not, he misrepresented the item and then it is up to me to accept or not. I am thinking it might be misbadged and be a 450, since you say the 350's are very rare, it has the small bumpers on it and the interior has been re-done in cloth. You seem to know a lot about these SL's I only know the 129's, I joined a classic car club and I want to fit in, that is why I am trying to find an older SL, since I just love the cars so much. My first MB was a 73 280C, great little car. My favorite MB was my 140 chasis, but the sedans hardly retain value, so I play with the SL's. Hopefully I will not be dis-appointed.
I am having the car shipped, so I don't have to deal with that hassle, and then I will probably start with the fuel system as you suggested, I would think from your post that it is a mechanical distributor, so hopefully it isn't bad. Should I remove the injectors and clean or replace those as well? The 129's have the gas tank between the trunk and ragtop storage area, is that the same on the 107's? Hopefully so i don't have to get under the car, I still need to buy jack stands! I will keep you all posted! Take care!
Regards,
Brian

[maheath]

WIth small bumpers and cloth seats (and a 350SL badge), it's almost certainly a euro car. If so, the VIN will start with WDB107043.

U-Haul rents 2-wheel and 4-wheel car trailers. A 107 SL on a 4-wheel trailer will run a little over 5,000 lbs, if you have anything that can handle that.

It is a mechanical distributor. A plunger controls the fuel flow. Buy the book I recommended and you'll understand exactly how it works.

The injectors may need to be cleaned, but I wouldn't replace them without going through the tests. They cost $20-$25 a piece, so don't pay anyone to clean them. Might as well replace them at that point. Just use Techron after you get it running.

The fuel tank is in the same place on the 107s, but the only access is from below.

[ctaylor738]

You should definitely buy the book - it's excellent.

Definitely drain the tank, clean the strainer, change the filter and put some fresh gas in it. Then see if you can run the pump with the return line unhooked into a container to get all the old gas out of the system. Then you may get lucky and get it running.

Even if you don't need injectors, you will almost certainly need injector seals.

Check out the Vintage Board for David Speed's adventures getting a long-dormant 280CE running - good lessons there.

Good luck!