Mechanics

NO SPARK OR FUEL

2001 Plymouth Neon

Electrical problem
2001 Plymouth Neon 4 cyl Front Wheel Drive Automatic 79,868 miles

replaced pcm, crank sensor, cam sensor if it sets with key on for about 15 min. Then will start and run all day
Avatar
Johnmoore
February 24, 2010.




Otherwise you mean it will crank but not start? Has the Check Engine light been coming on? If so, have you read the diagnostic fault codes?

I don't know if this applies, but it's worth mentioning. It was somewhat common for the dowel pin between the camshaft and sprocket to shear off, and the sprocket would spin slightly on the camshaft. This would mimic a timing belt that jumped a tooth. The Engine Computer would know that from seeing the change in the relationship between the signals from the camshaft and crankshaft position sensors.

When it looks as though the timing belt jumped one tooth, the computer turns on the Check Engine light and sets a fault code related to " cam and crank sync". At two teeth off, the computer shuts the engine down to prevent internal damage. At three teeth off, open valves will hit the pistons as the engine coasts to a stop and would be bent.

There is a procedure to relearn the relationship between the two sensors when one is replaced. It requires the DRB3 scanner, but I've never actually had to do that. The computer always learned the relationship as soon as the ignition switch was turned on, and the engine started right away.

Is it possible the fuel pump isn't starting up? 80,000 miles is a little soon for worn brushes in the motor, but you might have a helper try banging on the bottom of the fuel tank while you're cranking the engine.

Woops, I see you listed no spark or fuel. That would sure lead to the sensors you replaced. To prevent overlooking something simple but unlikely, try switching the Automatic Shutdown (ASD) relay with one of the other ones, but next I think I would send you to the dealer to ask if it's necessary to perform the cam / crank sync relearn procedure. I suspect the sitting with the ignition switch turned on for 15 minutes will be an important clue.

Caradiodoc

Caradiodoc
Feb 24, 2010.
Checked/switched the ASD Relay, no difference. Fuel Pump Turns on, Injectors do not activate, neither does the coil pack. If the key is left on for 15 minutes the car will start and once it's running it's fine, can shut it off and it'll fire up again without waiting

Going to check the dowel pin, noticed the camshaft is shiny around the sprocket bolt & washer like it's been spinning and wore the surface rust off the nose of the cam

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Dowel Pin is ok and timing is correct

Tiny
Johnmoore
Feb 24, 2010.
Interesting observation. Remember, it can't spin very much or the valves will hit the pistons. I hope the dowel pin is the problem, but I've never heard of it causing an intermittent no-start.

Caradiodoc

Caradiodoc
Feb 24, 2010.
Dowel Pin is ok and timing is correct

Tiny
Johnmoore
Feb 24, 2010.
Could it be the new pcm

Tiny
Johnmoore
Feb 24, 2010.
Chrysler has very little computer trouble to begin with. To have two do the same thing is even more unlikely.

Try something stupid. The next time it doesn't start, throw a battery charger on it on low charge, then try starting it right away.

Caradiodoc

Caradiodoc
Feb 24, 2010.
No go still same thing with battery charger

Tiny
Johnmoore
Feb 25, 2010.
Did see that the air bag dings and light is on after turning over for a few min.

Tiny
Johnmoore
Feb 25, 2010.
Help. I'm buried in service manuals and I can't get up!

Does your car use a Sentry key? That's a special gray key that's part of the anti-theft system. With this system, a special 4-digit code must be entered into the new PCM with Chrysler's DRB3 scanner that matches the code in the SKIM anti-theft module. There is nothing mentioned though about a 15 minute wait time if you don't.

If this system isn't on your car, let's go back to your previous comment about the pump turning on. Do you mean it runs for a second or two after turning on the ignition switch? That's normal, but it won't turn on again until the engine is rotating, (cranking or running). It can be hard to tell sometimes, so instead, use a test light or voltmeter to meaure on the dark gren / orange stripe wire at the ignition coil during cranking. If no voltage is present, we'll figure out where to go next. One test will be to measure the voltage on the two small wires on the back of the alternator, but we'll jump into that creek when we come to it.

Caradiodoc
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Caradiodoc
Mar 2, 2010.

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