williamigriffith
New Member
- Joined
- Jul 7, 2009
- Messages
- 11
- Reaction score
- 0
- Points
- 0
- Vehicle Year
- 2003
- Make / Model
- Ford
- Transmission
- Automatic
I believe I have a very lean condition that I have described in an earlier post. I routinely get the following codes: misfire on 4,5 and 6 with a lean bank 1. If I drive gently around town, no problem. If I make the truck work harder, particularly a long grade at 60 mph, it cannot maintain speed and the CEL immdediately starts blinking. If you depress throttle until downshift, it knocks like crazy at the higher RPM and you have to let up on the throttle. Bottom line, I have replaced air filter, fuel filter, plugs, wires, cleaned MAF and TB. I don't think it has anything to do with the catalysts, as the engine seems to rev ok to 3k under light load (accelerating in lower gears at low speed) All that seemed to be left to look at was O2 sensors and Fuel Pressure. Today I measured the fuel pressure, and I am a bit confused.
When I just turn on the ignition and don't start the truck, the pressure is between 14 and about 20psi, it is never exacatly the same. When I start the engine it goes up to 60 psi at idle, and stays there. From what I got from other sources, I thought the fuel pressure was supposed to drop a bit from ignition on not running to engine idling. Does the above sound normal? If the pump is supposed to be running until optimum pressure when the key is on, this one doesn't do it. On the other hand, pressure seems quite normal when running.
Any comments on the correct fuel pressure or the lack of power would be much appreciated. Thanks to several of you that have already suggested "seafoaming" and checking out O2 sensors.
Griff
When I just turn on the ignition and don't start the truck, the pressure is between 14 and about 20psi, it is never exacatly the same. When I start the engine it goes up to 60 psi at idle, and stays there. From what I got from other sources, I thought the fuel pressure was supposed to drop a bit from ignition on not running to engine idling. Does the above sound normal? If the pump is supposed to be running until optimum pressure when the key is on, this one doesn't do it. On the other hand, pressure seems quite normal when running.
Any comments on the correct fuel pressure or the lack of power would be much appreciated. Thanks to several of you that have already suggested "seafoaming" and checking out O2 sensors.
Griff