Engine Stalls / Difficult to restart

[cheekeemonki]

Hi Guys,

I am new to the forum as well as a new Mercedes owner. I picked up a
220SEB (1965) 6 CYL Automatic on ebay for CHEAPPPPPPPP.... and now I know why

Problem:
Car will start after sitting but idles rough (surges and dies down low sputters and quits) for a few minutes (unless you give it gas) and stalls out. Will not restart until you give it about 30 minutes to regroup. I can drive it but taking foot off gas is not an option.

I have had some work done on the car such as the timing reset, fuel pump cleaned, new fuel filter (which now looks like crap), new plug wires and plugs and new distributor cap and rotor.

Thanks for you help!

[kpb]

hey monkee, welcome. (cool screename )

If the new fuel filter now "looks like crap," there lies a tip for a major issue. Old partly gummy fuel, or. more likely, rust in the fuel delivery system. You are gonna get lots of ideas here, so, be ready...

[t walgamuth]

also check your grounds. bat to chassis and engine to chassis. also may need an auxiliary ground from battery to a starter mount bolt.

i had a similar problem on my 62 fintail 190c about 30 years ago.

this is not to discount the above post.

good luck

tom w

[Tomguy]

You sure that's a V6 and not a straight 6? Otherwise it's not the original engine, and a problem arises in that people dont know where to start with troubleshooting it. If it is a V6 conversion, what engine was used, and show us pics!

Check the plugs - you say they're new so they shouldnt be black and crudded up, they should be even in color. If it's the original straight-6, pull all the injectors out and soak them in carb cleaner overnight, they're probably filthy.

[cheekeemonki]

Tom...

It is the original engine "6 Cyl". Sorry for the confusion! As far as pulling all the injectors out (that would require me to get my hands dirty J/K)... Would fuel injector cleaner work?

[tram]

Start with the basic stuff. You obviously have a fuel contamination issue, so I'd start by addressing that and going from there. I'd highly suspect your electric fuel pump back by the tank is either worn out, full of junk, or both. If it isn't pumping the proper volume of fuel to the inj. pump, you'll have exactly all of the symptoms you describe. Over the years, I've noticed that these cars tend to blow black smoke if the rear pump isn't delivering ENOUGH fuel volume, and that often fools the observer into thinking that the car is running too rich and that the fuel volume is OK- like it's an injection pump or injector problem. I've had great success running these cars with an electric pump off of a fuel- injected VW Bus or Vanagon (1975- 91 model years) with a slight amount of rubber hose replumbing, and I use a clear plastic fuel filter inline between the tank and the electric pump to keep junk out of the pump. the VW style pump works great and is tons cheaper than an OE pump- if you can even find one. Had a VW pump on my 6,3 for years.
After you get the tank reasonably clean and adress the rear electric pump issue, just for giggles I'd get a valvecover gasket and do a valve adjustment. Then see how it runs. The big injection pumps and injectors are pretty bulletproof. I'd make sure, as I said, you've got clean fuel and a 100% working pump at the back. Then, valve adjustment.
Check the point gap, and check the distributor shaft for wear and wobble.
Remove your canister fuel filter at the engine and replace the element. Fill the canister with a fuel system cleaner such as Techron before you install it. Put another bottle in the tank.
As someone else previously suggested, check your electrical cables, connections, ground straps/ wires.
It'll take a bit to get her started with the Techron in the filter, but work through that, and then drive the car until you get up to op temp. If all seems well, take it on a drive. Run the bejesus out of it.
This may just solve your issues. Remember, if the basic stuff isn't right, the car isn't right!

[meltedpanda]

Here is your homework, read this....


1971 220

[Shab]

My recently purchased 1971 280SE W108 6 cyl was doing the same thing. Cold start up on high idle, then idle down to normal where it would just sit there and rock, chug & sputter miserably. After a while, it wouldn’t even do that, just cranked until the battery almost went flat. I believe it had been sitting for a while before I got it.
Here’s what got mine going. Cap, rotor, points, condenser, plug wires & air filter all brand spanking new when I got it. Someone did all that but didn’t bother with the spark plugs! Put in new plugs, gapped correctly (the others were not). Tank full of fresh 93-octane gas and a can of BG 44K, which I learned about on this site, to run through the system. Turned the key and instant WHOMPH, started right up. Coughed and sputtered a bit but then settled into a decent idle. Puttering around the block it would stall whenever I came to a stop sign. Did this for a few days. Refilled the tank with more fresh gas and got it out on the highway for the first time, after hours, no traffic and drove, and drove, and drove through the cool of the evening. As the previous poster mentioned, I also "Ran the bejesus out of it". The stalling has ceased and it’s purring like a kitten. I still intend to go through everything, especially the fuel filter and make sure things are clean as the guys here recommend. What a difference fresh quality fuel, additive and new correctly gapped plugs made. Next is checking dwell & timing but for now I will leave well enough alone. Runs good, starts instantly hot or cold and gobs of power. I definitely got lucky.

[robertbrown29]

after giving everything a good cleaning and checking all connections check the ceramic resistor .you may have two.they should be located near the coil on the drivers side fender.if it appears loose or brittle replace it.you can also bypass it temporarely. if this makes a difference,replace it.also make sure the engine is timed correctly.this forum has helpe me bring many mb's back from the dead.good luck