QuestionQUESTION: Car stalled and wouldn't restart after coming to a stop. It acted like it was
starving for fuel. Tried to restart again and again without success. Had it
towed home and when we tried to start it it ran fine. Change the fuel filter
which was extremely dirty. Drove it about thirty miles and it stalled again and
we had to have it towed home again. Again it started when we got it off of
the truck! Fuel pump?
ANSWER: Hi DeWight,
That sort of behavior sounds more like either the cam or crank sensor is in the process of failing. They will do so by loosing their output signal which kills the spark, then after they cool off they will work normally again.
To check for sure, check for whether you get any spark after a stall, putting the shaft of an insulated-handle screwdriver in one of the spark plug caps and holding the handle so that the shaft of the driver is 1/4" from the cylinder head and then watch for a spark to jump the gap when a helper cranks the engine. If not, then that is a good likelihood. But you need to know which sensor is bad. You can get a free readout of fault codes that might be stored in the engine computer at an Autozone parts store, or around $40 at an independent shop. The 0320 is for the crank sensor, the 0340 is for the cam sensor being faulty.
I doubt the fuel pump, which you should be able to hear run for about a second or so when you first turn the key to the "run" position. It is located in the fuel tank directly under the back seat so you can hear it coming from there. That would be one clue to whether the pump is not working.
Roland
---------- FOLLOW-UP ----------
QUESTION: Hi again, Roland,
The plot thickens. I changed out both the cam and crank sensors, drove
about 20 miles and it wouldn't start again. Let it cool and it starts. Any other
suggestions? Have ignition spark at the coil but I can't hear the fuel pump
run. Can the fuel pump be intermittent?
DeWight
AnswerHi DeWight,
If by "can't hear the fuel pump run" you mean for the usual 1-2 seconds when you first turn on the ignition switch (which I assume you have heard) then sure, the pump may be intermittent, or the fuel pump relay is intermittent. If you are getting spark, then the ASD relay is working which should mean the fuel pump relay also should work as the two relays are ganged together, and you should hear it click when you turn the key to run, then open after 1-2 seconds, in parallel to the sound of the fuel pump and the ASD relay.
You could check whether voltage is going to the pump for that 1-2 seconds (and while cranking) by putting your voltmeter on pin 12 (wire color dark green/black) of the gray/light blue 12-pin plug in the fuse box behind the dash (open the left end cap for access). Put the other probe on any shiny metal body surface. If there is voltage there, and still no sound from the fuel pump then the fuel pump is indeed intermittent. If you don't have voltage but you do have spark, then the fuel pump relay is flaky. So check this out while the engine is running OK, then carry along a voltmeter to be able to check it out the next time this fails.
Roland
