I have a 1999 Chrysler T&C Limited w 3.8L engine. It has just under 140K mi les and has served our family well in the 15+ years we have owned it. It wa s starting and running great up until a week ago when it died without warni ng while traveling at about 50MPH. There were no warning lights and no diag nostic codes. I pulled it off the roadway and it would start, then die imme idately. Eventually after 5 or 6 such starts, it failed to start any more. A check of the fuel rail showed no pressure and a check of the fuel pump sh owed it was getting power. In additon, the car would not start at all, but I found that it would start and run as long as I pounded on the fuel tank w ith my hand. The conclusion was that the fuel pump was defective, so I drai ned and dropped the tank and then replaced the integrated pickup/pump/regul ator/gauge float unit. After replacing the fuel pump and the fuel line filter, the vehicle took a while to crank over, but eventually started and ran well. I put a fuel gaug e on the schrader valve on the front top fuel line and it read 50 PSI while it was running which I believe is the proper pressure specification. Now that I have explained the background, here is the current issue and why I am asking for advice here in this group. The vehicle continues to be ext emely difficult to start (cranks for about 30 seconds., then catches and ru ns great) when it sits for even very short periods of time. My understandin g is that the fuel rail is supposed to stay pressurized between starts, but when I check it it shows 0 PSI. So why is it behaving this way? Is the new integrated pump assmebly or the fuel filter I installed somehow defective? (If so, exactly how does it work sicne there are two lines running from th e filter to the fuel pump assembly? Any theories?) By the way, there are no fuel leaks anywhere. All of the pressure clip fit tings seem to be good. Also the ASD relay and fuel pump relays are working correctly as well. I am certain that I got the large O-ring on the retain ing ring installed correctly and tightened down securely. I also believe th at I correctly re-connected the fuel tank connections (2 evaporative emissi ons lines and the filler tube).
Lastly, here is the procedure I have come up with to make the car start pro perly till I can get this fixerd permananently. I cycle the ignition key f rom off to the on (no start) position about 10X. I can hear the fuel pump run for about 1/2 second each time and eventually can determine the fuel li ne is actually pressurized from the slight change in how it sounds. I thne turn the key to start and it fires right up like it should normally.
My theory is that the replacement fuel pump assembly is defective in that t he back flow valve (assuming it has one) is not working correctly. Any tho ughts on what I could also check or a specific diagnoistic procedure that m ight identify the culprit here? I hate to think about draining and dropping the tank again unless I can confirm that is the problem. Thanks in advanc e for your thoughts. Bob