E320 Starting problem

[Jstrack]

My 1994 E320 (73K) will not start properly. Normally it should start within 3 seconds and not to depress the foot feed. Now after the engine cranks for a few seconds a depression of the foot feed is necessary, and it chokes a little before going to a smooth idle. This always happens when the engine is cold. The warmer the engine the less effort there is for it to start.
My mechanic could not find the problem. Says need to be dealer looked at. They had it once along with another problem, but this one did not get corrected.

Any Ideas on my problem would be appreciated!

Thanks

Jim S.

 

[Francois]

It is difficult to pinpoint an exact cause of the problem, but it would sound like there is something wet somewhere.

Have a look at the distributor cap and see if it is not wet inside. Spray some WD40 or something simmilar inside and on the rotor. Make sure there are no cracks in the cap and that all carbon residue is cleaned from all contact points.

Have a look at the HT leads. They may have a break in the insulation that would throw away spark and result in a weaker spark.

Take out the spark plugs in the morning before first starting the car. See if there are oil on them. This could also be the cause of your problem. If there are oil on them, then it would take a few cranks to start the engine.

Try to see if there are petrol in the petrol line before starting the car. There could be a leak somewhere that causes petrol from leaking out of the pipe while it is switched off. The petrol pump then needs to fill up the petrol line before petrol gets to the engine. This will also cause a slow start.

Hope this helps!

 

[mjtray]

Jim,

On a E320 you do not have a distributor cap. Its sounds like you have a classic problem that effects the M104 engine.

The problem in question is likely to be your OVP relay (Over Voltage Protection relay) which is located behind the battery and behind the plastic shield that covers your ECU. Next to the ECU is a silver relay which has a fuse on top of it. Its about 4 inches high and is held in by two bolts.

The OVP relay has a known design fault, which results in the internal soldering breaking down. The classic symptom is if your car starts getting harder to start when cold and then idles unevenly. In time you may also start to notice that your car stalls for no good reason.

Replacement is a 5 minute job once you have removed the battery.

The your local dealership will sell the relay for @ £45.00

Hope this cures your fault.

If in doubt, do a search on this forum and others for OVP related queries.

Cheers

Martin