Hello all. I was talking to my co-worker about some weird findings I was getting when diagnosing an intermittent fuel pump. The readings I was getting were about 30psi for a so called spec of 55-60psi. I said to my co-worker, I tried three different fuel gauges and came up with same readings every-time. Reason why, the fuel pressure kit is very sloppy and has been very abused by flaky hands. So after three gauges, I determined that the fuel pressure is exact. The vehicle in question is a E350 with a 5.4l year 2012. Client tells me he can cold start it only if he cycles the key 10 times. I have told time repeatedly the fuel pump is on it's last legs. Here is where I get skeptic. My co-worker tells me the fuel pump is fine and it is normal that I am getting readings like that so far up north and in altitude. So I went and got another e series truck with same fuel pump in it. Got 50psi. I accounted for maybe a drop or two seeping from a looses Schreader valve whilst taking readings. Truck started fine @ -37c. I can see that a drop of 5psi may account for altitude, but not 25psi. Who is right? Can altitude vary THAT much psi readings, or is my co-worker just not getting it?