Why is my 2004 Lincoln Navigator missing or choking out with
It could be the filter agian; it could be the fuel pump, or it could simply be either a vacuum leak, EGR valve, fuel pump relay, O2 (oxygen) sensor(s), plugged injector (carburated, fuel injected); fuel pressure regulator, hole in a fuel line (look for fuel leaks under engine, and along side the driver side of car (under car).
I suggest having a fuel pressure test performed, and having the vacuum system tested, which should include EGR valve. Another possibilty, simply; could be the air filter. If it is ripped, torn, full of dirt and debris (from driving), it is possible it is clogged and is preventing sufficient air flow to the intake which will cause the car to hesitate, stall, idle roughly, or even die when accelerator pressure is released, or braking is applied. My 93 Subaru had this vary issue when I purchased it, and when upon checking the air filter, it looked as though rats or mice had begun digging (chewing) at the air filter. It was so torn that the filter was starting to get sucked up toward the intake which was plugging the air vent (hose), causing a lack of proper air intake (this mixes with the the fuel). Improper air/fuel mixture will cause a car to not even start, or stay running for a few seconds.
You can determine the fuel pump by having someone kneel down by the back of the car while you turn the ignition to the "on" position - DO NOT START the car -- when the ignition is turned to the "on" position, the fuel pump is actuated to draw fuel to the engine (this is a "primer" method"). If the person can hear the pump engage, then the pump is good. To ensure fuel pressure, after the car has sat for about an hour or so, locate the fuel rail (chrome, silver usually, sometimes black) and find the black screw port (usually black) and remove it. Carefully (cover with hand or rag etc) and depress the needle inside the port; if fuel sprays out (won't be too too much) then you have fuel pressure. If no fuel comes out, then move on to having the fuel pressure regulator and fuel pump relay replaced. Even if these are good, (no way to tell) - these being replaced will eliminate them as possible culprits.
The O2 sensors can be detected as a possible issue by having a diagnostics test performed (free usually at participating auto parts dealers; Napa, Baxter's, etc) *States, auto parts dealers vary.
Please let me know if you need further assistance.
Guru, Premium Expert @ Fixya.com
Jun 28, 2010 |
2004 Lincoln Navigator