#1 Cylinder misfires. I've noticed that the problem (wiring ) has been worked on before. I tested the connections at all 4 coil packs(3 prong pigtail type connectors)All 4 positives read 12.4 , maybe thats amps? All the lefts,grounds?, read .07 BUT...#1 cylinder's wiring connector reads 4.8 at the center prong where as all center prongs at other 3 connectors read .07 I traced it to the powertrain control module, I think, and it looks like the readings are the same as above. Do I have a bad PCM?
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Re: #1 Cylinder misfires. electrical problem
I didn't hear you say that you took the spark plug out to see if there were any deposits on it. The best way to check a spark plug wire to see if it is doing it's job is to get a spark plug tester that you can manually screw out at 20k, 30k, 40k. Then start around 40k's and see if the spark can make the distance, but do it on all of the plugs so you can have some comparsions. Then find a range where a good known wire is making the difference than try it on the bad one. If is not making the distance and the wiring is in good shape, which wiring is measured in ohm, based on the length and you would have to look up your particular vehicle to see it's requirement per inch, but if all is good at this point; you might want to refer back to it's source, providing that the spark plug doesn't have oil deposits on it since that would be an important matter conserning your misfire.
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have a compression test done and look for a moving valve seat insert
it gives the knock, misfire
as it is no 2 cylinder it is mechanical because you have moved the injectors and coils , plugs and leads and it stays at no 2 cylinder
If you want clean engine oil then change the synthetic oil out and put in diesel oil 20w40
It will not harm the engine as it is the same as petrol oil but with more additives than petrol oil
it is cheaper and has heavy detergent properties that keeps the engine internals clean
from the gunk in the sump ,it is clear that changing engine oil on a regular basis is something you don't do but if you want a reliable long lasting engine , it is must do number 1
P0304 is engine misfire #4 cylinder Several things can cause a misfire #1 electrical which you have covered #2 Mechanical Test engine compression is should be around 150 cranking and 120 running . internal valve train components can cause bad compression and the valves then self. #3 fuel injector can be the cause suggest swapping with a know good cylinder and see if misfire follows injector.
What DTC code(s) are you getting?
You performed a compression test on cylinder #1; did you test cylinder #2?
Compare the readings, if there is a significant difference in compression readings between the two, you may have a bad head gasket, a bad valve, etc.
The bottom line, the problem is internal to the engine.
misfire, only on cylinder #1 bad spark plug or wires to it or COP coil to it. bad injector bad injection signals low compression on #1
there are simple tests for each, i will not ever guess on misfire.
misfire means, in English (not slang) THIS Cylinder #1 had weak power during the POWER stock. The ECU computes Velocity of each power stroke and Reports the weak. even an air leak to #1 intake runner can cause this or the injector #1 base gasket leaking. Air.
You forst need to see if that cylinder is getting fuel, this requires an injector flow test be run by a dealer or a well equipped shop, also you at home can check for intake manifold vauum leaks with a can of carburetor spray. You should also run a compression test on all cylinders and see if that one cylinder is lower than 5% from the hightest reading.
1. Bad or fouled Spark Plug at #1 Cylinder.
2. Bad or misfiring Wire going from the #1 on the Distributor/Electronic Ignition Coil to the #1 Cylinder.
3. Misfiring at the #1 on the Distributor/Electronic Iginition Coil.
a. Unplug the #1 Wire at the #1 on the Distributor/Electronic Ignition Coil.
b. Using an Auto electrical testing: Probe, wire and ground clip electrical, stick the Probe into the opening at the #1 Distributor/Electronic Ignition Coil. Use the grounding clip - clipped to a portion on the engine.
c. Start the Vehicle and check for rhythmic spark.
d. If there is NOT rhythmic spark, the Distributor/Electronic Ignition Coil needs to be replaced.
e. Turn off the engine.
f. If there is rhythmic spark: Reconnect the #1 Wire at #1 on the Distrubutor/Electronic Igntion Coil.
g. Disconnect the #1 Wire from the #1 Spark Plug.
h. Again using an Auto electrical testing: Probe, wire and ground clip. Insert the Probe into the end of the #1 Wire and clip the ground clip onto the engine.
i. Start the engine again.
j. Again Check for rhythmic spark.
k. If there is NOT rhythmic spark the #1 Wire needs to be replaced. (Replace all Wires as a Set).
l. If there is rhythmic spark then the #1 Wire is fine.
m. Turn off the engine,
n. Remove and Inspect the #1 Spark Plug. Clean if necessary and Regap.
o. Reinstall the Spark Plug and reconnect the #1 Wire.
p. Restart the engine.
q, If the code reappears:
r. Replace all the Spark Plugs.
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