No fire in two cylinders?

Hi,

There is a chance it is the coil. This design fires two cylinders at the same time, one on a compression stroke and the other on an exhaust stroke.

The PCM is what provides a ground path based on which pair needs to fire. So, if you could let me know which two are the problem, I can check to see if they are functioning from the same tower on the coil and signal from the PCM.

If you aren't sure, have the computer scanned. Most part stores will do it for you free of charge. Here is a quick video showing how it's done:

https://youtu.be/b2IJGfImVvw

Let me know.

Take care,

Joe

Hi,

The power supply is provided via 1 wire, a brown wire with a white tracer. From that point, a ground supply is provided to different parts of the coil to complete a circuit and create the spark.

Take a look at the pics below. Is it the brown/white wire that has power? Which one are you saying doesn't have power?

If you have a new coil and power to two of the towers, it sounds like the PCM isn't providing a ground path to complete the circuit.

Let me know.

Joe

See pic below.

Hi,

The brown/white wire is the power source. The other three are ground paths to the PCM. If you are checking them when it's running, that is why it is showing power.

That indicated there is no ground path for the dark blue/orange wire. No ground, no spark to the plugs.

So, first check the condition of the connector shown above. Make sure pin 1 (see pic above) isn't corroded, damaged, or pushed in, and the wire isn't damaged.

If that checks good, then you need to go to the PCM connector 1, Pin 7, and inspect it the same way. If it is good, then with the connector back on the PCM and the engine running, check that wire to see if there is a ground path being supplied. If there isn't, the PCM has failed. If there is, there is an open in that wire between the coil and PCM.

Let me know what you find. Also, the C1 connector will be solid black.

Joe

See pic below.

Hi,

Disconnect the connector at the coil. Using a test light, clamp one side to the battery positive. Probe the aforementioned wire (ground path) with the opposite side and crank the engine. If there is a ground path, the light will pulse on and off.

Let me know.

Joe

Hi,

Yes, it should be the same. Hopefully, it is just corrosion preventing the signal. Whatever is preventing the pulse is the cause of your problem. I have a feeling the connector is bad at the PCM or corroded.

The connector will be solid black in color. It's connector one. The wire is dark blue with an orange tracer at both ends. I attached a pic below showing which pin to check.

Let me know.

Joe

Hi,

I'm sorry to hear that it didn't take care of the issue. To answer your question, yes, they wire directly to the PCM. I attached a pic below showing the wiring.

Originally, I was thinking you had a bad connection, a broken wire, a bad pin in the connector, or something similar.

At this point, we know the coils are getting power. So, that leaves the wiring between the coil and PCM. Or they didn't fix the coil drivers. What you should do is check the wire between the coil and PCM for continuity to make sure it is complete and doesn't have excessive resistance.

Was the PCM repair done by a place that specializes in repairing them?

Let me know.

Joe

See pic below.