Compress Ingnite, thank you for the reply. you gave me a lot of info to look through. I have not looked through all of it yet. Let me answer some of your questions. I installed the BERU brand glow plugs part #GN858. I checked the OHM of them installed at the five pin plug as in the Diesel Giant guide. I have a cheap meter simular to his, same brand. At the same OHMs setting (200) , and subtracting the resistance from leads, all five would be at .5 OHMS. That should be good. I tested the five pins at the glow plug relay and through the wires .I am getting the 12 volts power to all places and to glow plugs. The light works right in the dash, and the car starts up good. The problem is at cold start, the idle not staying steady ,bouncing around too low (600 or lower),then up to where is should be at staying steady, (750). I am thinking 750 RPM's would be about right, this is from what I have read, I just got the car. I have a buddy with a 190D with the 2.5 , non turbo. He says his car will raise the RPM's on idle at cold start, then will lower when warmed up. On the fuel issue, I have drained the tank and put in fresh fuel in along with new filters. I have added some injection cleaner to the fuel. The car has ran at least a hour or two on new fuel and through new filters. This is at idle and drives down the road and back. It runs good warmed up. I poured a clear glass jar full of the fuel I drained out of the car. It had no black specs floating. Instead of just the green tint, it had a dark or grey tint also. I could not really see through it. It just looked old or not clean. I wouldn't think any or enough of the old fuel could be left to cause a problem. The primary filter shows nice clean fuel with just a tiny air buble in it. One other thing could be a clue, the exhaust on cold start up is a transparent grey color then a puff of black as the motor bounces back RPM's.It's not a blue smoke. It's not a thick grey smoke, like burning anti freeze. I did do a coolant system presure test. It held 15 pounds pressure for 15 minutes. That should rule out a head gasket problem, I would think. I am new to this car, but from what I've read and how my buddy's car act's, the car should raise the idle speed higher than it is on cold start up. If the EDS controls this, should I go in the computer codes direction? YUK! I have read the post on reading codes with analog meter. I don't have a analog meter, but I could get one. Again, thanks for your time and thoughts on my problem. Charlie Klippel