Hard starting, further continued

Pressure is holding at 40+PSI when not running? How long did he leave the pressure gauge on during this stage?Fuel pressure about 75PSI when running?

Longer cold and hard hot start at the same time? How hard of hot start do you have? Hot engine, and 10 minutes later is like forever and must step on gas pedal to get it started... that once it started rough as hell?

Not sure, at least overnight (I know that), but it may have been more.

Generally

A little longer than usual, but not too much longer. Maybe 3 seconds.

Occasionally it will take forever to start and I'll step on the gas and it will stumble to life, and then smoothed out. When he richened the mixture, it helped a little bit, but it made the car run rough at idle and in neutral. Richard

Ahh... okay. How is the cold engine acceleration? Hesitate a bit? Until warm?

I have eliminated fuel pump, accumulator, pressure compensator on the fuel distributor. The above answer will tell me about your warm up regulator.

I don't want overnight pressure reading. The pressure can be zero and car would start up fine. I want the pressure reading in 15 minutes... to 40 minutes.

The only problem is warm up regulator would not affect hot starting.

Nope. The only thing is that sometimes when it starts (hot or cold) it stumbles to life, but there is no hesitation when cold.

That's not the little thing that pumps hot air into the engine is it? That was disconnected.

Really, the overnight pressure could be 0 and it would start up fine? Didn't know that. I can only assume that they checked it out properly.

If the engine is too rich, would that also effect starting? I suspect this because the mechanic had set the lambda to 2volts, and then when I told him it wasn't starting right, he richened it beyond that. Once he riched it beyond that (very little), it started shaking a little at idle, especially in neutral. Richard

Warm up regulator is not at fault here as you said... it is that thing in front of engine with two fuel line hooked up on the top... very expensive sucker but can be obtained cheap if you buy Delorean's version instead... same thing.

Enrichening doesn't help in your case... I don't know what to tell you Rich...we eliminated everything except the fuel distributor.

Rich would start alot easier than too lean but too rich is also too hard to start. I don't use voltage to set the fuel mixture. Tell him to set it leaner then normal to see if it helps.

What do you use? Thanks, Richard

Believe it or not... I learned this from MB only mechanic who has been working on it for over 35 years... a can of carburator cleaner...

Take the filter housing off... the adjustment is as this... counterclockwise is leaning out... clockwise is enrichening fuel mixture.

You start by leaning it out (counter clockwise) until it gets rough then back off... do a bit of a turn at a time... 1/8 of a turn... and keep count so if you (for any reason) want to bring it back to original setting.

Once it get rough... back off... enrichen again so it is smoother. Squirt a bit of carb cleaner into the intake and listen carefully... if the engine slightly hums higher, enrichen just a bit more... a very slight raise in RPM.

You want to get to the point where you can't feel or hear any diffference in engine humming. Very small adjustment is needed.

If the engine stumbles, then it is too rich.