Cold Starting
 

Hello,

I just bought a 1991 300 TE and have been enjoying this forum a lot for about three weeks since. I was able to put in a new Stereo bypassing factory fader, new tie-rod ends, front wheel bearings and am loving this car.

However, it has a cold start problem. In the morning, I have to use starter fluid (!) or I risk killing my battery, it takes that long to catch. Using this forum again, I bought a cold start valve off ebay ($20) ($260 new) thinking that since the car wouldn't start when it was cold, it had to be the cold start valve. No dice.

The compression on this motor is 160 - 178 throughout (decent 165,000 miles)

Any ideas? The car starts fine if it warmed up.

Thanks for any advice,

Bowman

blown fuse in ovp relay.cover behind battery.relay with plastic cover on top.one or two fuses under plastic cover.either fuse blown and needs replacing or relay needs relacing.your description is a classic example of starting in limp home mode.when fixed you will see a power increase.these fuses are prone to blowing when car is jump started.

I second the ovp relay. It might also be a temperature sensor....either the one on the air intake or the one at the back of the engine. (with 4 pins and a big connector)

I checked the OVP relay fuse and it is good. I read somewhere that you can reset the relay itself. How do you do that? I also read on MB Forum of the UK that an Italian Tune Up solved one man's cold start problem. Ha, we'll see about that. I just a got a speeding ticket for 70 in a 55 so that's a challenge.

How can I test the OPV relay other than swapping out a known good one?

Also I noticed that the thin white plastic tube from the cylindrical thing in front of the "injection module" where the gas lines branch off to go to each cylinder, has broken off and it is meant to connect to the EGR valve. Also the Air Intake snorkel is cracked badly. (Sorry for lack of technical terms...)

Would this incomplete tube routing contribute to hard starting problem?

Thanks.

Also the ABS light is always on. I read in a thread here that it being on can't a OVP issue...

http://www.peachparts.com/shopforum/tech-help/41945-help-need-ovp-plug-schematic-4.html?highlight=cold+start

i think that is an OVP issue

What? Blown OVP Fuse, bad solder joint, OVP relay not fully seated, etc.
If your ABS light is always on (no power to ABS computer), and your engine is hard to start, then you have the classic symptoms of a faulty OVP relay.

http://i179.photobucket.com/albums/w.../OVPRelayA.jpg

http://i179.photobucket.com/albums/w...d/OVPRelay.jpg

replace the relay it is defective.the abs light being on with all your other symptoms confirms it.the other broken vac line and cracked intake air tube will have no effect on starting or running.

Solution
 

Thanks Everybody here, it was indeed the OVP Relay, I was doing up the intake system with new parts as well (plastic, sensors and filter) and now the car HAULS.

Any comments on the performance decrease a blown OVP Relay sees and also its relationship to the MAS, ASR and ABS because when I bought the car a month ago and six idiot lights on and now have reduced it to ZERO. (Two this time, ASR and ABS).

As you can probably guess this is my first Mercedes-Benz. I'm feeling like a German villain from a James Bond movie.

Wow, I gotta get me one of those TEs. Nice going.