The only way you can prime a diesel is to popur or squirt a fuel into the intake manifold of air cleaner.

P E H

After thinking about it I am going to place my money on Oldsouth's suggestion of the glowplugs. If it is a glow plug that is bad, maybe the dash light is only an indicator when the plug is really bad.

By the way, where is the glow plug relay?

The glow plug relay resides inside a square black plastic covering on the drivers side of the engine bay in front of the fender. You will see the wires leading to the glow plugs.

__________________
Chris

'04 ML500 - 53k, Inspiration Edition, Desert Silver
'11 Audi A4 Avant - Brilliant Black
'87 300SDL sold
'99 C280 Sport sold
'85 190E 2.3 sold

When I was looking for the glow-plug relay, I noticed that the return fuel line that goes between injectors #1 & #2 is very wet at one end. I still think that my problem is fuel related, not a glow plug. This might explain why the car fires up instantly, without the glug plug ligh acting abnormal and why the second I hit the gas lightly, the idle smooths out instantly. I think that the small leak on the return line is letting enough air come in to cause a bad idle.

Dang CJ, just test the glow plugs, return has nothing to do with running. The lines are probably old and brittle. Order some new line material (only mercedes metric line will fit)

CJ,

Other than the same problem you are having, my benz is doing fine.

I do not think its a glow plug problem (at least not with my car). I had ALL of them replaced by MB dealership and they tested them and so far all good. Since they are brand new, they wouldnt be coated with carbon.

I changed fuel filters too, still have the same problem.

If you ever find out what is causing it, please let me know. I will let you know if I find anything with my car. Goodluck.

Well I just tested the glow plugs and they are all fine. I am leaning towards the idea that this is fuel related. I will keep you posted.

Any other suggestions?
Thanks for everyone who has contributed.

CJ!

Did you ever try extending the glow process an extra 20-30 seconds AFTER the light goes out prior to starting?

__________________
Chris

'04 ML500 - 53k, Inspiration Edition, Desert Silver
'11 Audi A4 Avant - Brilliant Black
'87 300SDL sold
'99 C280 Sport sold
'85 190E 2.3 sold

Another thing - if your problem were fuel related, the vehicle will idle rough ALL the time.

__________________
Chris

'04 ML500 - 53k, Inspiration Edition, Desert Silver
'11 Audi A4 Avant - Brilliant Black
'87 300SDL sold
'99 C280 Sport sold
'85 190E 2.3 sold

I have extended the glow plugs, until the relay clicks, no difference.

How did you test the glow plugs? Current test or taking glow plug out and seeing how red hot it gets are only real way to test the glow plugs. A resistance test may detect a bad plug but not one that is marginal.

You may have one cylinder that has low compression and won't fire until it is slightly warm. Have you adjusted the valves lately?

P E H

The OM60x engines have hydraulic, self adjusting, valves and do not require adjustment. That is, unless things get really out of whack!

PE's point regarding visually inspecting the glow plugs is a good one.

__________________
Chris

'04 ML500 - 53k, Inspiration Edition, Desert Silver
'11 Audi A4 Avant - Brilliant Black
'87 300SDL sold
'99 C280 Sport sold
'85 190E 2.3 sold

Due to the mileage I may just replace all the glow plugs. The compression was checked about a month ago and is still within 5% of the specs for a new engine. This problem started all of a sudden, it was not gradual. Last year I hhad a glow plug go bad, but I the car ran & started fine. I just noticed that my glow plug light on the dash would blink. Crazy problem but I do appreciate everyone's input.