QuestionQUESTION: Every time I drive my car for an extended period of time, when I try to turn it on after having it off for more than a few seconds it turns over, but refuses to start. After I wait for 10 min to up to 2 hours (depending on how long it was driven), it starts up without problem. I'm actually typing the message on my blackberry as I wait... frustrated. I assume that it's related to heat; i.e. the more I drive, the hotter the car gets. At first, I thought it was electrical. I had gotten a jump from someone the first couple of times, and it started. So, I bought a new battery, and it did the exact same thing when I tried to leave the parts store. This, of course was post new battery installation. The parts guy said that the jumps were just coincidence because the car clearly has enough electricity to make the 4.6 litre turn over along with powering up all lights etc. I hear what I believe is the fuel pump when I turn the key before starting, but still nothing. I'm working on a colloege student's budget and my first car was n 84 crown vic. That said, I'm very familiar with and far from afraid of just buying a part to install myself. Please help.
ANSWER: IS or HAS the CHECK ENGINE light ever illuminated on the dash while driving the vehicle ?
Do you have more difficulty in restarting the car after it has been run for awhile if the fuel tank is FULL or when it is under 1/4 tank remaining gas ?.
The gasoline is what cools the electric fuel pump and when the fuel gets low, The gas is not covering the pump and can cause it to get overheated and cause low fuel pressure.
Fuel pump test:
1. Get yourself a helper.
2. remove the gas cap.
3. have one person listen in the gas tank at the gas cap opening.
4. have the other person turn the ignition switch to the ON position ONLY so as the dash lights come on. Do NOT attempt to start the engine.
5. As soon as the ignition key is turned to the ON position, The person at the gas tank should hear the fuel pump run for TWO SECONDS and then it should STOP.
6. Does it ?.
If you do NOT hear it run, in most cases the fault is the fuel pump relay or the fuel pump..
As soon as you turn ON the ignition switch to start the engine a 2 second ONLY battery voltage signal is sent from the computer to the fuel pump relay and from the relay back to the fuel pump in the fuel tank. This runs the fuel pump for ONLY 2 seconds of which pressurizes the fuel system in preparation to start the engine.
Once the engine starts, The computer BYPASSES the fuel pump relay and sends constant contionous battery voltage from the computer to the oil pressure switch of which is now CLOSED because the oil pressure is UP because the engine is running. Therefore the battery voltage flows thru the oil pressure switch back to the fuel pump to run the fuel pump constantly until you turn OFF the engine. If the oil pressure light remains ON after the car starts the most likely suspect would be to replace the oil pressure switch,.
---------- FOLLOW-UP ----------
QUESTION: 1) The Check engine light has come on while driving the car. I assumed it was because of the oxygen sensor because it went off while driving.
2) I have not tried to observe any correlation between the fuel level and the starting problem
I'm pretty sure the fuel pump is coming on. I hear fuel pump run for the two seconds when I'm sitting in the car, but I can do the 2-person test for clarification.
A little history:
The car was sitting for maybe 2 months or so before I got it. When I took it over, I drove from 1) Washington DC to
Virginia Beach, VA , 2) VA Beach to Philadelphia PA and back, and 3) again to DC and back. This was within the course of weeks or so. I had no problems with it starting. I then drove it from VA Beach to Charlotte, NC and back and had experienced the first signs during the drive back. I stopped to get gas and then the car did not start back up. I assumed it to be electrical, got a jump and it started right up.
I later had some problems with too much gas burning in the exhaust on account of the spark plugs & wires (which I consequently changed). The check engine light came on some time after that, but I didn't look into it too heavily. I assumed that the O2 sensor had gotten partially clogged due to the prior exhaust problem.
ANSWER: If you know how to retrieve the CODES from the computer, Do so. If not, Look at my ANSWERS TO PAST QUESTIONS on the allexperts site for the procedure and let me know what codes you get.
---------- FOLLOW-UP ----------
QUESTION: First, the "Service Engine Soon" light comes on after initiaing.
P039 History
P071 History
P083 History
I039 Current (I think this is the air suspension)
No ACP Codes
No SIR Codes
No TCS Codes
No RSS Data
PCM?
AnswerIF the fuel pump pressure/volume tests OK, I would manipulate the wiring to the cran sensors and the ignition control module just to see if you can and intermittent fault in one of the sensors.. If the problem continues and the fuel system remains OK, I would replace the ignition control module as they have a tendency to have internal intermittent faults due to high temperatures as they become heat sensitive.
