I still have no spark I have 12V to coil and 8V to Cam sensor and have change everything that I can think of. So know I am going to change the harness inside the car. I have change cam sensor , crank sensor, knock sensor, Coil, Computer, motor harness, and steering colum. Please help
But do they have good continuity?
Use an Ohmmeter and check the resistance between the body and the engine block. It should be 0 or extremely close to it.
Also, how exactly did you check for spark?
The "old man's" way was to take a screwdriver and shove into the spark plug boot while it's not on a spark plug and hold it about an inch away from "ground". You would hear a telltale click, or if done at night a blue to orange spark. depending on how "hot" the ignition is.
By hot I mean by how much voltage is being thrown to the plugs. DO NOT be touching any ground while doing this.. it's not a pleasant experience when 15KV+ goes coursing through your arms. Dunno if this would work on a newer vehicle.
Another note, it's current that kills, not voltage. But it don't take much to do it! Under the right conditions 1/4th of an amp.
Have you ohm-tested your coil pack (just because it is new doesn't mean it can't be DOA) and spark plug wires to ensure they are within specs? Are the plugs good? The cam and crank sensors are good? In addition to the coil, the cam and crank sensors make up the three main components of the ignition system.
EDIT: Here's a list from the DSM about crank, but no start possible causes. Might help you narrow down some more testing areas:
NO START PRE-TEST
POWERTRAIN FUSES OPEN
FUEL PRESSURE OUT OF SPECS
RESTRICTED FUEL SUPPLY LINE
FUEL PUMP INLET STRAINER PLUGGED
FUEL PUMP MODULE
FUEL PUMP RELAY FUSED B+ CIRCUIT
FUEL PUMP RELAY OUTPUT CIRCUIT OPEN
FUEL PUMP RELAY
FUEL PUMP GROUND CIRCUIT OPEN/HIGH RESISTANCE
FUEL PUMP MODULE
5 VOLT SUPPLY CIRCUIT
CKP SENSOR SIGNAL CIRCUIT OPEN
CKP SENSOR SIGNAL CIRCUIT SHORTED GROUND
CKP SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE
CKP SENSOR SIGNAL SHORTED TO 5 VOLT SUPPLY CIRCUIT
SENSOR GROUND CIRCUIT OPEN
ASD RELAY OUTPUT CIRCUIT
CRANKSHAFT POSITION SENSOR
IGNITION COIL DRIVER CIRCUIT OPEN
IGNITION COIL DRIVER CIRCUIT SHORTED TO GROUND
PCM - COIL
PCM - CKP SENSOR SIGNAL
OTHER POSSIBLE CAUSES FOR NO START
ok I have now change both harnesses under the hood the only one left is in the dash and I still have no spark. I need help I have changed EVERYTHING ALL Sensors, steering colum, computer I just don't kno what to do now.
Everything you have said I have checked and everythings fine. The parts are coming off of a running 99 neon the coil starts the other car but not 2000. I am just stuck
The parts may bolt up, but internally and such, is the construction, operation and specifications identical? That could cause a problem. Other than that, I'm not sure. If you have checked everything and it is all fine, I have no idea. You have gone through every single ignition component (and wiring I'm assuming) there is. If they really all fine, you should have spark. Really, no spark is generally going to go back to the coil. You might try buying the correct part and giving it a go to make sure that isn't the problem (back to my first statement). The wiring harnesses had to cost much, much more than a $60-$70 coil pack...
Power to the coil doesn't come from the dash, it'd come from the relays under the hood. Since the coil has power, the relays must be getting power. I'm completely clueless at this point. Everything has been changed and everything works/gets power. There's no reason for no spark. Are all of the relays for sure getting power/working correctly...like the ASD?
does this car have some sort of aftermarket anti theft on it? or remote start?
1995 Ram 1500- 240,000 miles
DD 2001 Plymouth Neon-53,000 miles starting the transformation into a decent looking car.
1991 Ford Mustang LX 5.0- Built.
2002 Chrysler Neon-177,600km RIP- SOLD with 226,700km
Now that I'm home and have access to the manuals...
The Auto Shutdown (ASD) relay provides battery
voltage to the ignition coil. The PCM provides a
ground contact (circuit) for energizing the coil. When
the PCM breaks the contact, the energy in the coil
primary transfers to the secondary causing the
spark. The PCM will de-energize the ASD relay if it
does not receive the crankshaft position sensor and
camshaft position sensor inputs. Refer to Auto Shutdown
(ASD) Relay—PCM Output, in this section for
The Auto Shutdown (ASD) and fuel pump relays
are located in the Power Distribution Center (PDC).
The camshaft position sensor and crankshaft position
sensor signals are sent to the PCM. If the PCM
does not receive the signal within approximately 1
second of engine cranking, it deactivates the ASD
relay and fuel pump relay. When these relays are
deactivated, power is shut off from the fuel injectors,
ignition coils, oxygen sensor heating elements and
The PCM contains a voltage converter that
changes battery voltage to a regulated 5 volts direct
current to power the camshaft position sensor, crankshaft
position sensor, manifold absolute pressure sensor,
throttle position sensor, A/C pressure switch, A/C
pressure transducer, and vehicle speed sensor.
ENGINE START-UP MODE
This is an OPEN LOOP mode. If the vehicle is in
park or neutral (automatic transaxles) or the clutch
pedal is depressed (manual transaxles) the ignition
switch energizes the starter relay when the engine is
not running. The following actions occur when the
starter motor is engaged.
² If the PCM receives the camshaft position sensor
and crankshaft position sensor signals, it energizes
the Auto Shutdown (ASD) relay and fuel pump relay.
If the PCM does not receive both signals within
approximately one second, it will not energize the
ASD relay and fuel pump relay. The ASD and fuel
pump relays supply battery voltage to the fuel pump,
fuel injectors, ignition coil, (EGR solenoid and PCV
heater if equipped) and heated oxygen sensors.
² The PCM energizes the injectors (on the 69°
degree falling edge) for a calculated pulse width until
it determines crankshaft position from the camshaft
position sensor and crankshaft position sensor signals.
The PCM determines crankshaft position within
1 engine revolution.
² After determining crankshaft position, the PCM
begins energizing the injectors in sequence. It adjusts
injector pulse width and controls injector synchronization
by turning the individual ground paths to the
injectors On and Off.
² When the engine idles within ±64 RPM of its
target RPM, the PCM compares current MAP sensor
value with the atmospheric pressure value received
during the Ignition Switch On (zero RPM) mode.
Once the ASD and fuel pump relays have been
energized, the PCM determines injector pulse width
based on the following:
² Engine RPM
² Battery voltage
² Engine coolant temperature
² Inlet/Intake air temperature (IAT)
² Throttle position
² The number of engine revolutions since cranking
During Start-up the PCM maintains ignition timing
at 9° BTDC.
Ok The car does not have anti theft or remote start. I have change the pcm and still no spark. I just don't understand the car had spark until I change out the motor. I have when through every connection and everthing is hooked up. Thanks you guys for all this help it is greatly appreciated
What is the same year engine (2000-2005)? I believe the 1st Gen engines (95-99) used different sensors and a different computer and such. I don't believe it would be "plug and play." If that is why you mentioned the coil pack from a '99, that could very well be the problem...the engine itself. I'd have to double check on that, but I believe the above is correct.