A few weeks ago when I got in my '97 with 6.5td, I noticed perhaps it was a bit weak on power, and when you really got on it, like entering freeway ramp, it would cut out for a split second. I thought mabey my filter was clogged even though I change it every 10,000mi. I also noticed a lack of the noise when you first turn the key and wait to start (fuel pump), but didn't think anything of it since the truck was running. My wife has been driving it for the last couple of weeks, without problem (she never gets on the gas), this past weekend I went to change that filter, opened the purge valve on top after installation, turned the key and nothing, no usual little spurt from there. I immediately thought of that fuel pump noise, or lack of, got underneath, disconnected the leads and connected directly to the battery, nothing. Swapped it out, and she purged normally and fired right up. I never thought the engine could run without a fuel pump. Is there small pump in the injector pump or something, or was it just running on suction?