Fuel System Problem

SULLUM100

MEMBER
1999 MERCURY MYSTIQUE
2.4L
V6
FWD
AUTOMATIC
113,000 MILES

Hello, I had my car's fuel pump changed a couple months ago since it would die out on me while I was driving at any random time. Two days ago it did the same exact thing I had my air conditioner on drove it for a good hour then out of no where the check engine light came on and started to stall out then died on me. I got it to start then a couple miles it started to stall out and did not start. I had the starter replaced, the mechanic said they cannot find the problem until they see it happen, but it has not happened since two days ago, but it does not start right up like it used to, help any ideas?

1 Reply

CARADIODOC

MECHANIC
33,871 POSTS

That is not how failing fuel pumps normally act. The check engine light is proof the fuel pump is not the cause of this problem. They are not monitored by the Engine computer. That computer did detect a problem. It set a diagnostic fault code and turned the check engine light on to tell you. The place to start is by having the codes read and recorded. That will indicate the circuit or system that needs further diagnosis, or the unacceptable operating condition. It is important now that you do not disconnect the battery or let it run dead. Doing so will erase the codes and that valuable information will be lost.

The most common suspects for this symptom are the crankshaft position sensor and / or the camshaft position sensor. Sometimes the engine stalls too quickly for a fault code to set. Then the mechanic has to go by the other symptoms and observations. He will check for loss of spark and fuel pressure, but those tests are only of value when the problem is occurring.