90 power ram

ok so the truck runs then will shut off, i can pull over and it will start right up and drive like it should then it will just shut off and will repeat this for as long as i am driving it. so i called about the codes the only one 1693 with the key trick. he said its the lift pump and in might be the inj pump, so i asked about replacing them its a Bosch inj pump for 1230 and 300 for install its good for 1 year warranted and a carter lift pump which i forgot the price. but i have an airdog 150 that came on my truck should i try replacing the filters on the air dog or just order a new one i don't know any thing about the air dog since it was on the truck when i bought it.is there some thing i should look at before i start throwing cash at it.

thanks shane

whiskers

1693 is a companion code that says there is no communication to the computer. Very common and on it's pwn tells you nothing. Problem sounds more like lift pump than the Injection pump. I had the same problem on one and it was a piece of foil from a fuel additive that had fallen into the tank, gotten through the pickup screen and would block off the pick up mtube, then when it died the pressure would release and it would run fine until it got sucked up again. Might be 2 miles , might be 200. Dealer spent 500 of my bucks replacing crap until I pulled the tank myself and fixed it for free. Don't throw cash at it until you isolate the problem, unless it is to put on a fuel pressure gauge to find out the problem. but i would start with are you getting fuel to the pump and on to the IP.