Has the new coolant temp sensor changed anything?

As for checking the cold start valve, sorry, I can't help. I've never had trouble with it.

RayH

unplug your maf and try to start any temp.If it starts your maf needs replacing

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1999 w140, quit voting to old, and to old to fight, a god damned veteran

Not that sort of MAF, can't unplug it.

R

5 years later, were you able to solve the problem?, I’ve been experiencing most of your symptoms and I was not able to solve the problem yet...

It's funny you should ask - at this particularly time! I had never resolved the problem satisfactory, but car still continued to run "OK"...Earlier this summer, I finally broke down and took it to a local Indy and they said - after having the car for 6 weeks - that I needed a new fuel distributor. They quoted me an $1800+ bill, so I took the car home.

Just this week I sent the FD off to have it rebuilt - haven't heard anything yet, but I'll try and post back.

ryan

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RG Newell

1984 300D
1972 250
1986 560SL
1991 300CE

when the fuel distributer on these cars wears it leaks from the actuater piston underneath into the intake ,anifold. when you stop the car it drips and drips into the manifold. then when you try to start its a no go. also the cold start valve can leak too, start there. it a LOT cheaper than the distributer.

i have 2 300ce i ripped off the fuel injection and smashed it with a hammer. adapted a 48mm weber idf. and a 1975 ford distributer. *****en kitchen

An update:

I received the FD back and installed it last week - got the car started for the first time in months...I had to back off (lean out) the mixture screw 4 full turns to get it to start...

Now, I'm still having trouble with cold starts -don't know if I need to further bleed the FD (first time to remove and install one of these), or if I need to continue tweaking the mixture some - but the car is hard to start when cold. I have to crank it for 5-10 seconds and then it will finally fire...runs pretty good from there, although I occasionally have a pretty severe 'off-idle stumble/hesitation.' Warm and hot starts are much better...

ryan

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RG Newell

1984 300D
1972 250
1986 560SL
1991 300CE

Try richening the mixture a 1/4 turn at a time until your cold start issue goes away. Have you correctly adjusted the duty cycle?

Sent from my XT1080 using Tapatalk

Look at this nearby thread:

1991 300ce m104.98 Intermittent Start Problems

and read post #5

Duke

I have been steadily leaning the mixture (CCW turn of mixture screw)...I had to go this way to get it to start...

I can not get the duty cycle to cycle - stays on 20% (I think)...I have had trouble with this issue for years! I know about the accumulator - haven't been able to check it yet. I am still having the hard cold start issue and a - seemingly random - stutter from stop, usually after driving for a bit, coming to a stop sign and then trying to accelerate from the stop...

Car will start in the morning, but takes 5 seconds of cranking and then seems to barely catch, and then fires right up!

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RG Newell

1984 300D
1972 250
1986 560SL
1991 300CE