Here is a tip from a veteran MB shop owner. He advises that as our engines get some miles and age on them they tend to leak air. Thus when starting you should give a little throttle, press accelerator pedal down, then start the car.

Steve

Another trick is to turn the key On and wait for 10 sec before turning to the starter position....this assures full fuel system pressure before crank..........

Totally frustrating, isn't it?

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joel

Prayers bring forth enlightenment.

Hey just-n.... i haven't had a chance to do it yet .... I just ordered some injector seals -- and will have it this week - then planning to do it this weekend ..also it is 40 - so am waiting for warmer weather also...

I also bought a fuel filter , fuel accumulator and OVP etc -- just to be sure!!

Update. Well I changed out five of the 6 injectors, and the stumbling start is basically the same. Although the car had been running plenty smooth, it runs even smoother now. The last injector is the one right by the cold start valve so I'll change it with the cold start valve. There are also some air hoses there and I just know they'll break if disturbed. I also tried a new fuel pump relay, which powers the cold start valve but again no change to the start. So that leaves me with the cold start valve as the last item to change. I'll throw in the towel after that.

glenmore
1991 300CE
2000 C280
1990 LS400

I will be doing the same thing tomorrow. Any tips on do's and don'ts would be appreciated. Am also prepared to change the rubber underneath the cold start valve, which also connects to the ICV. That will be the real challenge but have read some tips to deal with it.

Am hoping all these work will be worthwhile. What I am trying to corrrect is the false start to my 89 300e which I suspect to have leaky fuel injectors.

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joel

Prayers bring forth enlightenment.

5 of the 6 injectors have pretty good access. I did most with a regular allen wrench but a short stubby would have been handy or best would be a ball allen. You can probably reuse the insulators but might as well change them and you'll need both new insulator O rings and new injector seals. Flare wrenches are handy. I also just changed the fuel filter. The insulators with new O rings are a tight fit. I tapped them in with a 15mm socket. Oil liberally around the new O ring with fresh oil. Take care when pulling out the old insulator. There will be a lot of dirt and grit there stopped by the O ring. Liberally oil the shaft of the new injector before you press it into the new seal. What I did was to hold the new insulator, insert the new seal into the insulator, oil up the new injector and press it in. Make sure the injector is correctly seated into the seal and then pull it and the injector back out of the insulator. Put the new O ring on the insulator and press into the block and then plug in your new injector w/seal.

I bought a new cold start valve gasket. It is just a piece of stiff paper.

The new injectors did not fix my stumble start but the car does run even smoother and throttle response seems to be crisper.

If you have and tips concerning the cold start valve, let me know. That is my next step.

Thanks,

glenmore
1991 300CE
2000 C280
1990 LS400

I'm pretty sure the your problem is related to either the fuel distributor or the black Bosch EHA valve mounted on it or BOTH.

Try to disconnect the EHA the start the car after 10 minutes to see whether it starts or not. If it started that doesn't mean that the EHA is bad but it could be the fuel distributor.

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A couple of years ago, right after a head gasket replacement, I had an intermittent hard start. I took it back to the shop and he read some codes and suggested I drive it a bit more to confirm symptoms. He probably knew at that point what the problem was but didn't have the heart to tell me right after just doing a head gasket and water pump on the car. By accident I discovered that the EHA was not plugged in. I plugged it back in and the car was back to normal.

Could you over the diagnostic again?

Thanks,

glenmore
1991 300CE
2000 C280
1990 LS400

Very good write-up:
124 chassis Idle Air Hose tricks!

__________________
joel

Prayers bring forth enlightenment.

Another post suggested bleeding fuel through the distributor by taking the metal pipes one by one.

Anybody tried this with success?

__________________
joel

Prayers bring forth enlightenment.

most likely the problem

have them sent to a pro for cleaning much cheaper

Once the Idle air lines get hard they leek so replace them,Its cheep and solves a great deal of troubles when you go one step farther and replace the entire rubber pieces of the intake and vacuum ports.Very cheep insurance!

Thats a lot of parts!