Dodge: cummins engine idle, cummins diesel engine, diesel mechanic

Question
I own a 97 dodge ram with a cummins diesel engine. When i start it i have to depress the accelerator half way down. it will not idle by itself for about 5 minutes. when it warms up it idles around 600 rpm. it's an automatic and it stalls all the time. you almost have to drive it with one foot on the fuel and one on the brake. it's the last year with the old style injector pump(12 valve cam engine). I've changed the fuel pump(lift), fuel filter, and air filter. please help. I've asked everybody and every dealership. everybody said it was the lift(fuel) pump, it wasn't. The engine has 115,000 miles on it and i bought it with 100,000. it hasn't got any worse and i've tried raising the idle, nothing works! Please help me!

Answer
Matt,
I am going to forward this to a friend of mine (diesel mechanic) i will let you know when i get a response.I read the manual about checking the fuel pressure but it is too long and drawn out,This guy will know what the problem is.I will respond soon,Maybe i can help you!RamMan