[QUOTE=bdblk12v;3053565]I'm no injector expert. I belong to a forum competition diesel. I have a 1994 dodge cummins. I know that setting pop pressure does in fact change timing. Most everyone in the diesel performance side does up the pressure. I can say from experience changing pop pressure is a good thing. I had some stock injectors with low miles at 260 bar. They idled horrible and wasn't running good. I had a new set of nozzles 200hp over stock set at 290 bar. It idles way smooth and runs great. Fuel pressure does play a large role too in the cummins inline pump. Stock pressure is around 20psi. The higher pressure helps fill the pump plungers. General 50psi or so at wot is a good rule of thumb. Hope this helps.[/QUOTE

Depending on the dodges injector pump design may make a signifigant differance. Personally I have not advocated going beyond nineteen pounds supply pressure with these older mercedes diesels.Since there are still a couple of unknowns.

If they are signifigant or not is still the question. We have a lot of new site members that would perhaps do things without thinking them through. I still think the time will come when we regularily increase the fuel supply pressure. It is pretty certain that really low fuel supply pressure can hurt things. Especially on the 616 four cylinder engine over time. That engine will run quite well at very low substandard base fuel pressures. Unfortunatly doing it can have a serious price attached to it over the long term. I have to add that is my opinion. As times move along I feel more and more certain about this. Thanks for your input. The more people share things the more we learn. These cars are very old in comparison to the dodge trucks with their cummings engines. So a lot more effort is stressed on more fuel system maintenance types of issues.

I do advocate checking the base fuel pressure on the 616 engines as a cost effective method of reducing the risk on the number one rod bearing parting company. A permanent fuel pressure gauge may be that models best friend. A twenty dollar expendature for all the parts and gauge. Less so on the five cylinder 617s. Yet to me still a factor.

I am also far from being an injector literate person. We on this site have not yet discussed upping the pop pressures. We have examined increasing the fuel supply pressures some..Actually it is still at the stage of suggesting that people just check what they have for being adaquate. Low substandard fuel supply pressure existing gives many issues.