Problems with 7.3

[gaboy013]

I have a 99 7.3 SD 4X4. the PCM went out about a month ago it took the guy working on it 3 weeks to figure out it was the PCM. I got a used PCM from Ebay from a trusted seller and the truck ran ok for about a week until today I never had the power with the newer PCM that I had with the old one and it just did not seem right today it just lost power and it will crank and idle but has No power ..... I noticed that when I turn the key on for the glow plugs to warm that the little vaccum pump is not running on the left side of the motor area would this make the truck run like this???

[matts7.3]

im no tech, but I have the same year and ran into somewhat the same probs. mine ended up being the CPS, clogged fuel filter and an exhaust leak on one of the uppipes. I know the 4x4 and a.c run off that vacuum pump but not sure on anything else. If you havent already you may want to check all your fuses, when I first bought mine used, it ran even worse but found a couple of fuses blown and seemed to run better after replacing them.