280SL Euro missing - PeachParts Mercedes-Benz Forum

desert · #1 11-19-2010, 02:06 PM

Need some help. My 85 280SL Euro ( 110 engine) has been running fine but this morning when I pulled it out of the garage it was missing on a couple cylinders and when I gave it gas it was blowing smoke out the back. A couple of blocks later it was running on all six and no smoke. I live in Arizona and it runs great when the weather is hot/warm but now the nights are turning a bit cold ( in the 40s) and this is when it starts acting up so it must have something to do with the temperature. The car only has 60K original miles on it and doesen't burn any oil. Local garage ( non Mercedes) said maybe valve stems leaking oil but I'm thinking something to do with the fule injection.Any advise appreciated....Thanks.

RadioTek · #2 11-19-2010, 04:31 PM

Do you live in a section of the state where the fuel mixture is seasonally adjusted? If you do, you may have a rubber part in the fuel system that is being affected by the additive.

How long has it been since your last tune-up?

There may be an advance issue due to a leaky vacuum hose or fitting.

If I understand your description, it runs poorly until it gets warmed up. That sounds like a spark advance/timing issue.

You might be ahead of the game to pro-actively go through the vacuum hoses under the hood and replace everything you can get your hands on. It may cost you some time and tubing, but you could fix and/or prevent a LOT of problems. These things are known to have a finicky attitude toward vacuum issues.

Just tossing out a few ideas,
Scott

desert · #3 11-19-2010, 04:52 PM

Thanks for your suggestions. I don't think we have fuel adjustments here in the Tucson area at least I've never heard of any but will ask local garage. I agree that vacumm hoses could be the problem but why would lower temperatures affect them? Wouldn't that be a full time problem not related to temps? Plus many of the hoses have already been replaced. I haven't had a tune for a two years so that could be my next step but not many miles maybe 20K since the last tune. Isn't the fuel injection system influenced by changes in temperature? Could that cause it to run real rich for a while while it's cold? I'm just trying to narrow down what the problem could be before taking it to a shop and have them replace parts until they come up with the solution. Think I'll take it out in the sticks on hwy77 tomorrow and blow it out and see if that helps. Thanks again...Desert

desert · #4 11-20-2010, 10:05 AM

Correction and update.....Correction is only 5,000 miles since last tune up two years ago, not 20K, must have been thinking of my other car, 2004 E320 wagon. Update....took SL out early this morning, same temps in garage and outside, everything was perfect, ran fine, no smoke so now I don't know what is going on but guess something to do with temperature. Will still blow it out and then keep fingers crossed but will appreciate any suggestions or ideas....Thanks Desert

Walrus · #5 11-20-2010, 12:21 PM

Quote:

Originally Posted by desert

Think I'll take it out in the sticks on hwy77 tomorrow and blow it out and see if that helps. Thanks again...Desert

Italian Tune-up!

petesmga · #6 11-20-2010, 07:38 PM

I'm up in Mass so not the same temps but I had the same problem with my 79 280sl a few days age. Water had condensed inside the distributor side of the ignition leads !. And before you say it the cap, plugs and wires are all under a year old and bosch. My parts guy is giving me a new set of wires but I'm going to put some of that water repelling grease on them. BTW the car was in the garage and my 84 280sl which was left out was fine.

ctaylor738 · #7 11-21-2010, 01:41 PM

I would start with a check of your warm-up regulator (control pressure), and cold start valve. Sounds like you are getting too much, or maybe not enough enrichment with the colder temperatures.

As a quick check, try disconnecting the electrical lead on the cold start valve and see if it still does it.

desert · #8 11-23-2010, 02:57 PM

Update...Thanks for all the replies and suggestions, I'll print them out for future reference. I did take it out Sunday and ran it at about 90 mph for quite a while ( in the desert) and that seems to have solved the problem at least for now. I don't drive it very often and when I do it's usually never over 50 mph max so I think it just loaded up on me. I have to go up and down a pretty big hill to and from home so in the future I'll kick it down every now and then to blow it out....Thanks again, Desert