Hello guys,I am new here.Well not really.New as a member but old as a reader of all those treads that helped me so many times.Thank you all. Wright now I have a problem where I dont know what to do next. The car in a question is my wife 1989 300E m103 engine 3L.Well it first has rough idle,so I adjusted a bit air mixture, going so often to smell tail pipe like a dog chasing its tail.And it was fine for a short time, when she said that gasoline smell inside a cab.So I removed air filter to find out that EHA is leaking bedly.OK,bought new one, replaced it then starting became problem.Even before this happened the car never started at first when cold.Now becouse I have so many smart guys around me who knows everything I let one by one work on the car just to find myself with no point out.Honestly I am the one to blame,but like always it came too late to me.Now I dont know what to do next.I allready replaced spark plugs and EHA. One of the guys find that that EHA plug does not mach numbers at EHA. So he switch them. Then we find out that gas goes to distributor but does not goes to injectors,looking at bone dry spark plugs.The other brainer sugest that distributor is cloged.Poore me,I dismantled it in a pieces just to find everything is clean as a wistle. Got it back and then revers wires on the EHA plug the way it was.I dont know why, but first time I felt pressure under the air measuring plate,Before with leaking EHA there was nothing to feel.OK I said ,at least some gain.But car still dont start.I was even suspicious about timing chain,so check it and its fine right on the money.Now I am in desperate need of anyone knowing what to do next.Please help.

OVP replaced? If your getting fuel then its the best bet. The ignition coil is a good option also, no one ever seems to replace them on these cars. Check the fuel pressure, anything above 40 psi should be good.

As suggested above replace or resolder the OVP. cold starts depend on it for operation.Spray carb cleaner under air plate to test for ignition .it should run for a few seconds
The other failing item; check the Fuel pump relay .Best to clean the pins and resolder if fuel pump is erratic in operation. .
mak

Today I bought a new set of spark plugs at a local store.I know they are not BOSCH and they are resistor type,but I tought anything new will be better than those old one.These are NGK.Now I do have spark at all cylinders but still no start.At one moment it sounded like its geting to catch but it was just for a short moment til I aded a pedal a bit.That got me worry.Did I just choke it with a pedal or it will got dead anyway. Thanks for your input.I did try with used good coil ,Now I dont know is it coil or new spark plugs,but who cares there is a spark there now.For the OVP it is new one replaced not long ago,just for the safety,but I did try exchange with the old one anyway just to make sure,but with no difference.Thank you for your try to help and if you have any idea just shot .

You say you altered the mixture. Have you tried putting it back to where it was originally ?

you didn't mention the fuel filter..did you replace that too? A really clogged fuel filter could cause this...unlikely..but it could...

Thank you Mak Very kind of you.You not gonna beleive me what I found in my intake today.Down below a trottle plate it was a flood of gas and ether of numerious times trying to do the same thing.Honestly I was suprised when it did not react on ether.OK I cleaned all that pool from down under with a hand pump.Why did not start with ether got me worry even more. Not knowing what to do next I went to open new spark plugs to see is it any change.And that was in the wright direction.From all new and clean plugs I could see clearly wich one worked at least a bit by black carbon deposit on brand new porculan.Only two of tham showed some signs,while every single one was flooded with gas.That is why did not react on the ether.If system didnt get any fuel ether will start in no time.We ofen do ether on company trucks in the cold winter mornings. Some of the trucks have glass bottle of ether by the factory(only non glow plug trucks) and ether goes in the intake by fumes over the rubber hose.So just a bit of it in the intake, should show a sign of start.In my case I beleive it was to much of fuel (flooded plugs) plus the ether.

fuel filter will generally be after the fuel pump...I would replace the fuel filter, it's cheap and fairly simple and you've done everything else...why not the fuel filter?

Thanks for a good taught Kiwi but only god knows where it was

Thanks Cliffmac fuel filter is apsolutelly on to do list

I would definitivelly step on fuel supply tomorow when I got back from work.That fuel flood got me worry. Thanks to every one,for any idea you could posibilly have, just shot it out loud.Any sugestion works.