Mechanics

CAR TURNS OVER BUT WILL NOT START

1994 Chrysler New Yorker

Electrical problem
1994 Chrysler New Yorker 6 cyl Front Wheel Drive Automatic 20700 miles

I have a 1994 chrysler, it turns over really strong but will not start, I replaced the : crankshaft sensor, the fuel pump, the computer, the fuel pump relay, the ASD relay, also the fuel pump fuse is good, I put the old computer back in and put another camshaft sensor in and it started for about 1 minute then it quit, I then restarted it and it ran for about 30 seconds the it shut off, finally before I replaced the coil I double checked the crankshaft sensor wiggled the wires a little made sure it was plugged in completely and the I then got fire and the car almost started, so I replaced the coil and it started right away I drove it for 2 full days with no problems, then I got in to start it and it started doing the same thing I unplugged the wire harness to the coil and then plugged it back in the car started for about 2 minutes then it shut off again, I replaced the spark plugs and the wires it turns over strong but still will not start I will try to mess with the crankshaft sensor a little more is there anything you guys can suggest before I go to my last option and pay a huge bill on diagnostic tests. My email address is : thakabu@cox. Net
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Thakabu
April 1, 2009.



A diagnostic test might be a lot cheaper than throwing a bunch of parts at it. First you need to determine if spark, fuel, or both are missing. A fast way to determine if both are missing is to use a test light or voltmeter to monitor the voltage on one of the small wires plugged into the back of the alternator. Near battery voltage should appear for two seconds after turning the ignition switch on, then it will go off. If it appears again while cranking, the Automatic Shutdown relay is turning on. That tells you the crankshaft and camshaft position sensors are working properly.

It's not likely a fuel pump would quit after it's up and running. It IS common for the ignition coil, cam and crank sensors, and other electronic parts to fail when they get warm. A MAP sensor can do this, but it will usually set a diagnostic fault code and turn on the " Check Engine" light. If the MAP sensor is bad, very often the engine will start and run as long as the gas pedal is moving.

When the engine stalls, try to observe if it's sudden, such as when turning off the ignition switch, or if it sputters and slowly dies out. Dying suddenly is usually electrical; slowly dying is most likely a fuel problem.

Be careful when replacing computers. If you put in a body computer or an engine computer from a car that has the anti-theft system and your car does not, one will self-program the other into thinking it's on the car, and it won't start. The same thing can happen if your car has the anti-theft system but you borrow a computer from a car that doesn't have it. When you put the borrowed computer back, it will self-program the body computer, and both will have to be replaced. Once either of these computers become programmed to look for the disarm signal at startup, the programming can not be undone.

Caradiodoc

Caradiodoc
Apr 3, 2009.


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