1996 Aerostar with fuel pressure problems.

[teltek]

I have a 96 Aerostar that sat unused for a couple of years. Had engine trouble, so my nephew put a used engine in it(I think from an Aerostar). After replacing various things it seemed to run very well. After a few days it started running very badly with white smoke coming from exhasut. I replaced all ignition parts with no luck. I finally replaced the fuel regulator and that fixed it. I did not have a fuel pressure tester at that time. It ran great for a few more days and then the same problem returned. I bought a fuel pressure tester and the pressure was about 65. But it would not hold. If you turned off the key or engine it would go to 0 immediately. With the engine running I removed the vacuum hose from the regulator and gas came out. I put a new regulator on and the problem went away. It runs great. But I fear I may have too much fuel pressure causing the regulators to go bad. After replacing the last regulator, the fuel pressure ocillated between 65 and 85 with no ill effects in engine running that I could detect. After a few minutes it seemed to stabilize at about 65. No black smoke that I can notice. It runs fine for now. Is my pressure too high and if so what can cause it?

Thanks

Haven't had any replies yet. Hope somebody has some ideas. Wanted to add that I retrieved the engine codes when it first happened. Consistantly had misfire codes, rich fuel mixtures codes and high EGR flow code. While replacing the ignition components I also replaced the EGR valve. Like I said none of this helped until I replaced the fuel pressure regulator. Since replacing the EGR valve I consistantly get low EGR flow code. Even now after repalcing the FPR the second time and it running fine, I still get misfire codes, rich fuel codes and low EGR flow. One last thing, I know everybody says I should get black smoke with too much fuel, but when the FPR fails, I get white smoke from the exhaust and it smells of gas.

 

[BrooklynBay]

Welcome to this forum! I've moved your thread into the Aerostar section. Do you have a list of code numbers? Did you replace the engine coolant temperature sensor?

 

[teltek]

Thanks for replying. Codes I get are 300,1132,401,and 172. I talked to a Ford tech and he felt sure with that high a fuel pressure that I had a restriction or problem with the return line. The third fuel regulator has now failed due to the high pressure. I guess the diaphragm can't handle that pressure. I have not had a chance to check it out yet. What do you think? I have not replaced the coolant temp sensor by the way.