Got a 96 12v, 472,000 miles. While pulling the camper home on I-80 I began a slow loss of speed and power when encountering even the slightest grade. At cruising speed in OD, I'm doing 70mph at about 1750 rpm. Anytime I begin to ask a little more from her (uphill), I begin a slow descent to about 60 and 1500 rpm, throttle on the floor the whole time.

I have excellent high pitch turbo whistle however I do not have any guages to tell me the boost. Frankly I don't know much about turbos.

Everything is stock, except a K&N and a straight pipe.. I have the history since 30,000 miles, always had good care.

Do turbos lose their spunk after a while? It doesn't blow smoke and I get about 14-18mpg.

I equate this to an asthmatic patient in a bout of status asthmaticus, only I can't give a molotov of albeuterol and atrovent or install a CPAP machine.

I drove an non turbo diesel vehicle with a trailer at the fire department recently and I can equate it to that.

Sorry for the long story. Please give me some advice or things to check.

 

need to check fuel pressure at the injection pump inlet, sounds like one of three things, pluging fuel filter, failing lift pump, of failing overflow valve

 

One thing I might add is that nothing major has happened lately. It still starts good, drives good and nothing is out of the norm. Only when I am asking for some power. There is always a lot of talk about the power and torque with the cummins. If this is how they act as they age, then I am not sure about what is so good with them.