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I have a Onan 4000 that turns over, but is not firing. I've replaced the coil, condensor, ignition controller, new spark plugs, new spark plug wires, any ideas
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If it is backfiring even during idle, there are a couple of possible issues. Check the obvious and least expensive first. Make sure you have correct OEM spark plugs, check ignition wires. Then check the ignition coil and trigger module, there is a procedure for doing that in the Cummins Onan manual. A manual can be obtained from http://www.advanced-power-technologies.com/ or local Onan RV dealer. This will give you the ignition coil resistance and the ignition module resistance. Also has anyone messed around with the carb, or has it sat for long periods, too lean a fuel mixture can cause backfiring. Good Luck ;)
If you're not getting fire to the spark plugs after changing the coil pack, it could be due to a few different issues: Faulty new coil pack: It's possible that the new coil pack you installed is faulty or not compatible with your vehicle. Double-check the specifications of the coil pack and make sure it's the correct one for your make and model. Faulty spark plugs: If the spark plugs were not replaced along with the coil pack, they could be worn or damaged and not firing properly. Check the condition of the spark plugs and replace them if necessary. Wiring issues: There could be a problem with the wiring or connections between the coil pack and the spark plugs. Check all of the wiring and connections to make sure they're secure and free of damage or corrosion. Bad ignition control module: The ignition control module (ICM) controls the timing of the spark and sends a signal to the coil pack to fire. If the ICM is faulty, it could prevent the spark plugs from firing. Check the ICM for any signs of damage or wear, and replace it if necessary. Faulty crankshaft position sensor: The crankshaft position sensor tells the computer when to fire the spark plugs. If the sensor is faulty, it could prevent the spark plugs from firing. Check the sensor for any signs of damage or wear, and replace it if necessary. If you've checked all of the above and still can't find the problem, it may be best to take your vehicle to a mechanic or dealership for further diagnosis and repair.
If there is no spark, the ignition module may be bad, or the wiring to it. Have the module ohmed out. Also the magnetic trigger assembley that is on the rotor that sweeps past the ignition module maybe broken. If they check ok, suspect the control board
Check engine light on ? Code's ? What engine ? 2.3 l 4cylinder or 3.ol v-6 This vehicle has coil on plug ignition system , not coil packs ! a coil per cylinder . If new coils an still has no spark , has no B+ voltage to the coil or the PCM isn't controlling them . Without testing i'd only be guessing as to the problem .If the repair shop you had it to can only say it had to be the coils , I'd find another shop to take it to ! Autolite Coil on Plug Ignition troubleshooting
Check the spark plug and the ignition coil for good sparking.
Get the spark plug out, or with another spark plug connected to high voltage cable, outside the motor, the outer part of the plug connected to motor ground and see if spark is present at cranking.
Check your connections, recheck them, start from the battery go all the way through in your testing. Personally it soulds like an issue at the coil not getting fire.
Before servicing the vehicle, refer to the Precautions Section. NOTETwist the spark plug boot one-half turn in order to release the
boot. Pull on the spark plug boot only. Do not pull on the spark plug
wire or the wire could be damaged.
Remove the intake manifold cover, if required.
Disconnect the left side spark plug wires from the spark plugs.
Disconnect the left side spark plug wires from the ignition coil.
Remove the spark plug wire clips from the Manifold Absolute
Pressure (MAP) sensor bracket and the heater inlet and outlet pipe tab.
Remove the spark plug wire assembly.
If replacing only one plug wire, open the retaining clips and remove the appropriate spark plug wire.
Disconnect the right side spark plug wires from the spark plugs.
Disconnect the right side spark plugs from the ignition coils.
Remove the spark plug wire assembly.
If replacing only one plug wire, open the retaining clip and remove the appropriate spark plug wire.
To install:
Install the spark plug wire assembly.
Connect the right side spark plugs to the ignition coils.
Connect the right side spark plug wires to the spark plugs.
If replacing only one plug wire, open the retaining clip and install the appropriate spark plug wire.
Install the spark plug wire assembly.
Connect the left side spark plug wires to the spark plugs.
Connect the left side spark plug wires to the ignition coil.
Install the spark plug wire clips to the MAP sensor bracket and the heater inlet and outlet pipe tab.
If replacing only one plug wire, open the retaining clips and install the appropriate spark plug wire.
Install the intake manifold cover, if required.
Fig. 2.2L Engine
Firing Order: 1-3-4-2
Distributorless ignition system
Fig. 3.1L Engine
Firing order: 1-2-3-4-5-6
Distributorless ignition system
Fig. 3.5L Engine
Firing order: 1-2-3-4-5-6
Distributorless ignition system
Fig. 2.4L Engine
Firing order: 1-3-4-2
Distributorless ignition system
Fig. 3.1L Engine
Firing order: 1-2-3-4-5-6
Distributorless ignition system
Fig. 2.2L Engine
Firing Order: 1-3-4-2
Distributorless ignition system
I had the same problem with my 85 cj7 this week, I relpaced the ignition control module, plugs, wires, cap, rotor and the the coil; still had no fire to plugs. the problem turned out to be my distributor, replaced it today and she fired right up. Most likely it was the pick up module in the distributor that went bad.
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