We just put in a new V8 5.2 liter engine to replace the old one and it will start but it will only idle for about 30 seconds and then it dies. We can hear the fuel pump turn on, we replaced the fuel pressure regulator. We checked the throttle body sensor it seems to be okay. The fuel pressure is about 40 before we start it and within the guidlines of the chiltons manual while idle around 18. Is there any suggestions out there? My husband is a diesel mechanic and has a very creative mind but he is at his witts end and I don't know how else to help him. Any suggestions are welcome.