300teman

I have a 1993 300te 4matic for about a year now. It has always had
The cold start issue. So far I have change both Fuel Pressure check valves in fuel pumps, fuel filter, accumulator and still no luck. I thought
That I was just losing fuel pressure. I check the ohms on the Cold Start Injector and I get tone. But when I check the power on the connector when cracked I get no voltage. Is the Cold Start Injector the issue? I have also read
On another forum it could be the engine temp sensor.

Need help bad.

MyBigBenz

Cold start problem? Can you explain your symptoms a bit more so we can properly diagnose the problem? The engine temp sensor is plausible, but hardly likely if you problem is actually in getting the vehicle started. It would more likely cause runability issues regarding power, etc.

300teman

Thanks for replying.
In the morning or if the car has sat more than a hour it takes multiple key turns to start it
If I do not press on the gas just right. Then after it starts it will rough idle for about 5 seconds then it's fine. It accelerates fine on the highway and traffic but it starts like I described everytime if left sitting for an hour or more.

300teman

I just purchased a MB diagnostic tool. Waiting for it in the mail. Any help will be great.

loclark757

Which diagnostic tool did you get? How's your fuel pressure?

300teman

I have not checked it with a gauge. When the car is warm it runs fine.
I read 1500 ohms (cold) on the cold start sensor in the rear of the engine. And 300 ohms when warm. I also got tone on the cold Start injector.
Here is the diagnostic tool
http://cgi.ebay.com/ebaymotors/Diagn...2#ht_855wt_948

loclark757

Wow very nice! That's the one I've been looking for...

Keep us posted!

Thanks!

300teman

Ok I have looked at the cold start valve. I get 12v on the connector when I try to crank the engine. But when cranking it with the injector on I get no mist. I tried a used one and still no luck. Took the valve off and i crank it and get good fuel pressure Well at least I am getting closer.

300teman

I got a tested CSV off ebay and when I crank the car no mist. I am beginning to think it's not the CSV. I get voltage on the connector I am stumped. Could it be the Engine Temp Sensor?

300teman

I placed 12V DC on the CSV terminal using my voltage generator and I heard it click. I called George Murphy a veteran MB Tech and he said that means its a good valve. I even put 11.5V on it and it still clicked. I get 11.5V to 12V on the connector in my car. I wonder is the fuel pressure is strong enough.

Ameen

so any word on this?? my car does this also and its annoying as hell

300teman

I still have this issue. I have downloaded the Ke Jetronic fuel system manual and it says the thermal timing switch turns on the Cold Start Valve. I looked for it on my 103 engine and cold not find it. The dealership told me it was the 4 prong sensor in the rear of the head next to the fire wall. They said it was a multi functional sensor. Engine temp/thermal timing I change it and still the same problem. I have read threads and people have changed everything plugs, injectors, OVP, MAS, fuel pumps, check vavles and no change. I have read more people being defeated on this issue than succeeding.

300teman

Ok I put 12v to the cold start valve using my dc generator I could hear the solenoid clicking on th CSV. I started and it fired up not strong as I thought but that could be because the solenoid was going so crazy it was cutting off the fuel too soon. I will try it again. I read on a forum a guy wired a button inside his car to turn on this valve manually )

Ameen

have you tried this??

http://www.landiss.com/mixture.htm

BlackStar Stig

Have you tried changing the OVP yourself?
That's where I would start I think, perhaps borrow a working OVP with the same serial number from someone just to test it out before spending money on one..

300teman

I will check with one of the shops that Have a few 300E parts cars for a working OVP.

@Ameen I have not tried those adjustments. I heard about this on a forum and they guy said it was very risky.

Ameen

Risky? Dunno.. Seems like a multimeter should
make it pretty straight forward..

A lot of people with similar problems have fixed it completely by doing the adjustment..


Just sayin...

300teman

I am willing to try anything at this point. I feel like you this is a very annoying problem Merc should not start like this no matter how old they are I had a 77 Cadillac Seville fuel injected and it started first key turn everytime. I will wait till the weekend to try it. Have you tried it yet?

Ameen

Not yet... But I should be this week.. My cars response and power sucks and misfires like crazy during cold start but clears out when it warms up..