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Ricardo Hohl
Ricardo Hohl, Master Certified Tech
Category: Dodge
Satisfied Customers: 4300
Experience:  Automotive instructor at Porter and Chester institute
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2000 dodge neon: bucking..rpm..the cam and crank sensor

Customer Question

I have a 2000 dodge neon that has thrown the P1391 code. It starts bucking and missing once the car heats up and it gets around 3k rpm or so. I have replaced the cam and crank sensor and still no fix. I/ve checked the ends on the wires and still no change. Is there anything else that I need to do that will fix this problem? I've also tried adding octane booster and fuel system cleaner, still no change. The car would stop messing up sometimes for a week or so but then it comes back.
Submitted: 7 years ago.
Category: Dodge
Expert:  Ricardo Hohl replied 7 years ago.
hi, its possible that you have a target magnet loose or crack remove the cam sensor and check the magnet on the cam shaft see if loose or crack, let me know
Customer: replied 7 years ago.
could this problem possibly have anything to do with a bad fuel pump?
Expert:  Ricardo Hohl replied 7 years ago.
hi if P1391 code keeps coming back after you had reset and replace the cam and crank sensor then the problem is on the synchronization of this two sensors , they are supposed to synchronize them self in to one signal at hi speed and if they don't then is either power, ground, or signal wire problem, but first we need to check the mechanical part of the cam shaft were the cam sensor is mounted, if the magnet is crack or loose this problem will happing .
Customer: replied 7 years ago.
How do you check the power ,ground and signal wire. Where are they located ? If one of those is bad do i replace the whole wire or what ? Thanks for all your help.
Expert:  Ricardo Hohl replied 7 years ago.
the power and ground to the sensors can be check with a multimeter just look for 5 volts with key on at the sensor harness connector or just follow the wires to see if broken or rubbing against metal. but i really think you should remove the sensor and look inside on back of the cam shaft see if the magnet is ok, if ok then check the wires and if damage wire is found then replace the wire. they go from the sensor strait to the computer.
Customer: replied 7 years ago.
I checked the camshaft magnet and it's not that . what else could it be?
Expert:  Ricardo Hohl replied 7 years ago.
ok, have you check the timing belt?, if is of by 2 degrees it will st this code
Customer: replied 7 years ago.
Will the timing belt just skip teeth like that? Because it was fine and this happened all of a sudden.
Expert:  Ricardo Hohl replied 7 years ago.
yes it will the best thing to be sure is to check if is one or 2 degrease of then that is going to prevent synchronization of both cam and crank, make sure the tensioner is secured and the belt is tight , align the belt and then try again, because at this point that is the last possible cause other then the computer. do you need a picture on the timing marks ?
Customer: replied 7 years ago.
Yes that would help me out alot. Thanks.
Expert:  Ricardo Hohl replied 7 years ago.
ok, here it is can you please copy or print this page right , to prevent deleted pictures.away, like now!
  1. Remove accessory drive belts.
  2. Raise vehicle on a hoist and remove right inner splash shield.

Fig. 69

  1. Remove crankshaft damper bolt. Remove damper using Special Tools 1026 three jaw puller and 6827-A insert (Fig. 69).
  2. Remove lower torque strut.
  3. Lower vehicle and place a jack under engine.
  4. Remove upper torque strut.
  5. Remove right engine mount to engine mount bracket through bolt.
  6. Remove power steering pump assembly and set aside.

Fig. 70

  1. Remove engine mount bracket (Fig. 70).

Fig. 71

  1. Remove front timing belt cover (Fig. 71). CAUTION: Align camshaft and crankshaft timing marks before removing the timing belt by rotating the engine with the crankshaft.

Fig. 72

  1. Insert a 8 mm Allen wrench into the hexagon opening located on the front of the belt tensioner pulley (Fig. 72). Rotate the pulley counterclockwise until it contacts the stop. While holding tensioner pulley against stop, insert a 1/8" or 3 mm diameter pin or Allen wrench through the hole located to the left of the hex opening (Fig. 72). While pushing pin into hole, allow the tensioner pulley to rotate back. Almost immediately, the pin should engage the locking hole to prevent further movement of the pulley.
  2. Remove timing belt. CAUTION: Do not rotate the camshafts once the timing belt has been removed or damage to valve components may occur.


Fig. 74

Fig. 73

  1. Set crankshaft sprocket to TDC by aligning the sprocket with the arrow on the oil pump housing, then back off to 3 notches before TDC (Fig. 73).
  2. Set camshaft to TDC by aligning mark on sprocket with the arrow on the rear of timing belt cover (Fig. 73).

Fig. 75

  1. Move crankshaft to 1/2 mark before TDC (Fig. 75) for belt installation.
  2. Install timing belt. Starting at the crankshaft, go around the water pump sprocket and then around the camshaft sprocket.
  3. Move crankshaft sprocket to TDC to take up belt slack.
  4. Remove the pin or 1/8" or 3 mm Allen wrench from belt tensioner.

Fig. 76

  1. Rotate crankshaft 2 revolutions and check the alignment of the timing marks (Fig. 76).
  2. Install front timing belt cover.
  3. Install engine mount bracket.
  4. Install right engine mount to engine mount bracket through bolt.
  5. Remove jack from under engine.
  6. Install upper torque strut.
  7. Install power steering pump assembly.
  8. Raise vehicle and install lower torque strut.

Fig. 77

  1. Install crankshaft damper using M12-1.75 x 150 mm bolt, washer, thrust bearing and nut from Special Tool 6792. Install crankshaft damper bolt and tighten to 142 Nm (100 ft. lbs.) (Fig. 77).
  2. Install accessory drive belts.
  3. Install right inner splash shield.
  4. Lower vehicle and perform camshaft and crankshaft timing relearn procedure as follows:
    • Connect the DRB scan tool to the data link (diagnostic) connector. This connector is located in the passenger compartment; at the lower edge of instrument panel; near the steering column.
    • Turn the ignition switch on and access the "miscellaneous" screen.