No Spark

Hi,

Have you checked the ground between the ignition control module and engine? It is under the top cover. See pic 1.

Let me know. Also, let me know if it is only spark that has been lost. Also, has the ignition control module been replaced?

Take care,

Joe

See pic below.

I cleaned the contact points on the ground wire which appears to be rust and corrosion free. But the ICM is the original as far as I know. Could the Camshaft Sensor cause this? The ICM seems to be expensive, haha.

Hi,

The Camshaft Position Sensor (CMP) is used to correlate crankshaft to camshaft position so that the Powertrain Control Module (PCM) can determine which cylinder is ready to be fueled by the injector. The CMP sensor is also used to determine which cylinder is misfiring when a misfire is present, but it doesn't determine ignition spark timing.

The PCM sends the ignition control pulse to the ICM on these circuits based on crankshaft position signals. You have replaced the CKP already. Either the ICM is bad, the PCM is bad or there is a wiring issue. Make sure none of the pins in the connector are damaged, corroded, or bent.

I can't guarantee it, but I feel the module has failed. Are you able to retrieve diagnostic trouble codes? Is there a salvage yard where you could get a used ICM?

Let me know.

Joe

Unfortunately, none of the Salvage yards seem to have my car or its equivalent. The only code along with the blinking engine light at rough idle, is P0300. Described as a Random/Multiple Cylinder Misfire.

Added a new starter and starter solenoid today. Which allowed it to crank right up but rich gas smell and the misfires. If I very slowly give it gas. It revs up but still is missing.

Hi,

Don't run it too much like that. It will damage the catalytic converter because it is getting raw fuel into it.

At this point, are you able to get a new ICM? You could hook it up and see if that takes care of the issue. If it doesn't, return it.

Let me know.

Joe

New ICM still misfires at idle. Got 3 codes 1 for p0300 for random/misfire. 1 for O2 sensor 2. And 1 for the camshaft sensor which is the 1st time that code has shown.

Hi,

What code did you get related to the O2 sensor and camshaft position sensor?

Let me know so I can look into both of them.

Joe

New Cam Sensor, started up and after a few seconds since the computer was clear registered a P0300 code. Idles rough no other codes.

If that is the only code, it could be something not even related to electronics. Have you confirmed there are no engine vacuum leaks and the fuel pressure is within spec?

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Do me a favor. Locate the fuel pressure regulator on the fuel rail. There will be a vacuum hose attached to it. First, confirm that hose is in good condition. Disconnect the vacuum hose and inspect it for evidence of fuel in the hose.

Let me know what you find.

Joe

I found the issue I believe. Injectors 3 and 4 have no power. Swapping around the injectors I found only 1 and 2 sprays. Even when swapping around injectors, so all four injectors work in fuel rail port 1 and 2. But not 3 and 4. Moving on to try and track down a short in the wire harness etc. Any ideas?

Hi,

Each of the fuel injectors has a gray wire to it. That is the power supply and should have 12v at all times with the key on. Confirm it is a power issue first. It won't be a fuse or relay issue because all 4 injectors get power from the same place.

If you look below, I attached a portion of the wiring schematic and see where a problem can be if injectors 3 and 4 have no power but 1 and 2 do. There is a point where all four gray power wires are spliced. It is near the rear of the engine.

Take a look at the pics I attached, specifically pic 1. (I had to cut the schematic in half to make it readable). Note the splice and its location. I have it circled in pic 1.

Let me know what you find or if you have other questions.

Take care,

Joe

See pics below.

It appears with a multi meter all four injector wire harness connectors all show a steady power. So, I think that means the injector pulse is what's not working only in the third and fourth cylinders.

Not sure what to do, haha. Making a 4-sale sign now.

Hi,

You are correct. On the affected cylinders, both have a gray wire, but both also have another wire, one is Pink with a black tracer and the other is light blue with a black tracer.

Here is how it works. You have 12v to the gray wires at all times when starting or in the run position. You confirmed that is good. For the circuit to be completed, the PCM provides a ground path at a specific time and for a specific length of time. That completes the circuit and actuates the injector. So, if you have power and this happened to both cylinders at the same time, I suspect there is either a wiring issue, connection issue, or the PCM has failed.

The first thing I need you to check is if there is a ground path being provided by the PCM. A Noid light can be used to confirm this or even a test light. Here is a link that explains how to test:

https://www.2carpros.com/articles/how-to-test-a-fuel-injector

Since we know we have power, if you use a test light, disconnect the connector on the injector, identify the pink/black first and place the test light on that pin and the opposite side on the battery positive. Have a helper crank the engine. When the PCM provides the ground path, it should light. It should actually strobe on and off while cranking.

If the light doesn't strobe, here is what I need you to do. Disconnect the negative battery terminal and wait for approximately 10 minutes.

Next, locate the PCM which is on the passenger side front of the engine compartment. There will be two connectors. Disconnect the black one. The other one is blue and not relevant.

Next disconnect the injectors (cylinder 3 and 4). Using a multimeter or voltmeter, confirm there is continuity between the injector connector and the PCM connector. At the connector, locate pins 75 and 76 (see pic 2) using pic 1, identify the wire color at the injector and which pin it goes to in the connector.

If there is continuity, confirm there is no corrosion or damage at the PCM connector. The pins can break from corrosion or actually short together. Since these two are side by side, I have a feeling there is an issue with the connector, but we need to check.

If the connectors are good, the wiring is good, and there is no evidence of damage, suspect the PCM has failed. You could place a Noid light on the injector connector to see if it pulses on and off to confirm. If it doesn't, the PCM is my primary suspect.

Let me know if this helps or if you have questions.

Take care,

Joe

See pics below. Note: We need to get it running. It's worth more that way. LOL

I haven't been able to get the PCM out or disconnected. I did find this and 4 wires of the 5 were broken. Some harness that plugs into the radiator and overflow tank. I used a speaker wire to try and reconnect each one. No luck.

Thank you for all the help. I'm going to have to give up on this and sell it "as is" unfortunately.

Hi,

Those must be related to the cooling fan and level sensor. As far as the PCM, I attached the directions below for removal and replacement. Since you are only testing, the relearn shouldn't be required.

I have a feeling the connector is causing the issue or the PCM itself has failed.

If you change your mind, let me know. You can get remanufactured PCM's for a good price and they come plug and play based on your VIN number.

Let me know.

Take care,

Joe

See pics below. The last pic shows the location. It is behind the front bumper.

Replacement PCM installed. New Code P1336. Something about the crankshaft relearn procedure. Still only two injectors have a pulse. Drove about thirty miles attempting the relearn procedure for the one code. It would not learn it. Apparently, an advanced scanner tool can fix that. But I don't have one. Not sure what else to try. About 99% sure after the relearn it will just catch the misfire code again and be back to square one.

The car listed above is a convertible. Red. Needs new top brackets and top itself. Plus has some issue involving the above-mentioned. I have replaced more than even mentioned in this whole ordeal. This car is for Sale. This Vehicle is located near Searcy Arkansas.

A picture.

Hi,

The relearn is called a variation relearn. It does require a scan tool to activate the relearn. It won't reset by driving. See pic 1 below

As far as the injectors are concerned, each one has a gray wire to it. It supplies 12v with the one. Do they all have power? If not, there are two splices we need to check. If they do all have power, let me know which two injectors is not getting a ground pulse from the PCM.

Also, if only two cylinders are working, I'm surprised you were able to drive it.

Let me know.

Joe

All injectors have the same power and the same resistances according to multimeter. Also, when swapping injectors, the two that did not spray, now work. Looking at the engine from front bumper, the two injectors closest to driver side do not spray. But swapping they spray in the left side. And with all four injectors spraying they all work themselves.

I have replaced so many parts by now with everything else working well. I guess somehow, it's enough to start and run roughly and weakly with mass fuel consumption too. About half a tank every thirty miles.

Hi,

Wow! That's a lot of fuel. So, the two will not function but do have power to them. That indicates either the wiring between the injectors and the PCM are not making contact or the PCM is bad.

Have you checked them? Have you checked the connector for corrosion or any type of damage?

Let me know.

Joe