To check spark, grounded a plug on the block and found constant spark from all plug wires with the ignition turned on, not cranking, what is causing this?
Do mean that the plugs are firing even though the engine is not cranking?
here is a little theory for your information and I included a lot of information because I did not see which engine you have in your vehicle.
My diagnoses follows ****
DIS is a distributorless system used on 1.9L, 2.2L, 3.1L, 3.4L, 4.0L and 4.6L. The 2.4L uses a similar system referred to as the Integrated Direct Ignition (IDI) system. The operation of DIS is quite similar to operation of the C3 I system. Systems consist of 2 (4-cylinder), 3 (V6) or 4 (V8) ignition coils, ignition control module (located under coil pack), a camshaft position sensor, 2 Hall Effect crankshaft position sensors, necessary wiring, and the ignition control and fuel metering portion of the PCM. On the 2.4L IDI system, ignition coils, ignition control module and spark plug connectors are all combined into one unit which plugs directly onto the spark plugs.
Spark is timed by a signal sent from a crankshaft position sensor mounted through side of engine block instead of from a crankshaft position sensor mounted at crankshaft pulley (such as C3 I). This signal is received by PCM (through ignition control module) and is used to trigger each coil at the proper time. As with the C3 I system, each cylinder is fired consecutively with the cylinder opposite it in the firing order. On V8, cylinder No. 1 is paired with No. 4, No. 2 with No. 5, No. 3 with No. 8 and No. 6 with No. 7. On V6, cylinder No. 1 is paired with No. 4, No. 2 with No. 5, and No. 3 with No. 6. On 4-cylinder, cylinder No. 1 is paired with No. 4 and cylinder No. 2 is paired with No. 3. Each pair of cylinders is fired by its own ignition coil.
On all models except Saturn and 4.6L, crankshaft position sensor is mounted on bottom of ignition control module, or near the ignition control module. On Saturn, crankshaft position sensor is mounted under the intake manifold. On 4.6L, crankshaft position sensors ("A" and "B") are mounted on side of engine block between cylinders No. 4 and 6. On all models, the crankshaft position sensor protrudes through the side of engine block to within .05" (1.3 mm) of an internally-mounted crankshaft reluctor ring. Sensor position is not adjustable.
The reluctor is a piece of metal, cast with the crankshaft. On all models except 4.6L, reluctor has 7 slots machined into it, 6 of which are equally spaced (60 degrees apart). The seventh slot is spaced about 10 degrees from one of the other slots and generates a synchronization pulse signal. On 4.6L, reluctor has 24 evenly spaced notches machined into it and an additional 8 unevenly spaced notches for a total of 32. On all models, as crankshaft rotates, notches in reluctor ring change the magnetic field at the tip of position sensor. This creates an induced AC voltage signal in the sensor windings, resulting in RPM reference signals which are sent to PCM by the ignition control module. This allows PCM to compute crankshaft position and RPM
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However, the only way you are going to get spark is that the PCM must see a CKP signal
Therefore, if the engine is not cranking and you are still getting spark then you have some type of electrical interference feeding into the CKP circuit
Assuming you do NOT have any aftermarket items installed then we have to seek what is causing the feedback
Additionally, we need to seek A/C voltages
That being said though, almost everything in your car is suspect
The most common would be the MAF
Start unplugging all sensors and electronics while watching the phantom spark
When the spark goes away you found your source of interference
If all else fails, the feedback could be internal to the PCM
Personally, I have never seen anything like this in 20+ years
The closest I can recall is a coil that is saturated at all time but that was the old days when a car only had one coil
Let me know if there is anything else I can do to assist you in your diagnoses
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If the light is not coming on at all it is
possible that the computer actually went out. However I would suggest
that you start with the battery , just to be on the safe side. Check
the voltage of the battery, you may want to take it out and have
someone bench test it.
Also measure the voltage at the starter
during cranking, when the key is turned (if battery is charged) you
should see 12v at the starter.
One more thing (before check the computer) you can
check is the ignition switch and check the wires at the ignition, even
though I am convinced the computer has gone out.
Tell us news.
If it has a distributor, lift the cap and look for spark traces, black
lines that show where the spark has been following a crack or other flaw
in the distributor. If you see any problems in the distributor cap,
replace it and the problem will probably go away.
If that isn't it, check the spark plug wires. Run the engine at night,
in the dark, and look at the spark plug wires to see if there are any
sparks. If there are, replace the wires
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If you are getting a good spark, then the next place to look is fuel. When you turn the key on do you hear the fuel pump run for about 2 seconds?
Car not starting or turning over indicates towards multiple possibilities.
It can be issue with battery or weak battery. But if battery checks out ok, then
it can be starter issue or faulty alternator or problem with low fuel pressure
or no spark at spark plugs due to dirty spark plugs or faulty
ignition coil or injectors getting cracked or dirty and needs to be cleaned.
To confirm the problem, the basic troubleshooting is required.
Click this link below and follow the troubleshooting:------
http://technoanswers.blogspot.in/2012/02/car-starting-issues.html
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This will help.
Thanks.
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Engine will crank, occasionally fires, sometimes backfires. Should not have the constant spark should I? What could cause the constant spark?
Battery is good, the question is why the continuous spark without the engine cranking?
An expert would know a 99 Lumina doesn`t have a distributor.
Yes, that is the question, what could cause there to be spark without the motor cranking?
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