| Author | Message | ||
     Dave (Discoverover) New Member Username: Discoverover Post Number: 39 Registered: 11-2002 |
My 96' 4.0 discovery (5 spd.) has misfires in the #3 cylinder. The crank sensor (flywheel) has been tested and seems to be the problem. Out of curiosity, has anybody had misfires linked to the crank sensor or flywheel? | ||
| Paul Long (Humveewannabe) New Member Username: Humveewannabe Post Number: 30 Registered: 03-2003 |
I've had misfires blamed on valves. Two days ago my DII would not start. Cranked fine, no spark and no fuel. Read my own OBDII codes, "crankshaft position sensor fault". Removed it, to be sure it was clean, looked fine. For the hell of it, I reinstalled it, and since the battery neg. cable is removed to properly remove this sensor, I put it back on to try it. It started. Don't know if the sensor is going bad, or if it's possible that the ECM didn't pick up that bit of the program. I'm not driving it until I replace the sensor since there is no "limp home" or back up strategy. When this sensor fails, the vehicle will not start. Here is a list of other failures this sensor can cause from my factory manual. A 14 mm spacer is used with manual gearbox. A 18 mm spacer is used with auto gearbox. "It is vital that the correct air gap is maintained, if the air gap becomes too wide the CKP signal becomes too weak, causing possible engine misfires to occur". 1. sensor assy loose 2. incorrect spacer fitted 3. sensor open circuit 4. sensor short circuit 5. incorrect fitting and integrity of sensor 6. water ingress at sensor connector 7. ECM unable to detect the software reference point 8. ferrous contamination of crank sensor pin/reluctor In the event of a CKP sensor signal failure any of the following symptoms may be observed; 1. Engine cranks but fails to start. 2.MIL remains on at all times. 3.Engine misfires(CKP sensor incorrectly fitted) 4.Engine runs roughly or even stalls. 5.Tachometer fails to work. 6. Flywheel adaption reset - ferrous contamination. This info was found in chapter 18, page 13. "The CKP sensor is the most important sensor on the vehicle and without its signal the engine will not run. The signal produced by this sensor allows the ECM to determine crankshaft angle and speed of rotation. The ECM uses this information to calculate ignition timing and fuel injection timing." Sounds like a good part to keep in the glove box, even Nathan has to order mine from the UK..... about a week wait. Good thing mine quit in the driveway. I'll know after replacing mine if it may have been causing misfires while on its way out.... |
