GEN 1 Misfire - 4 cylinders

[randyb]

Before sending to the shop, I am going to switch 02 sensors and see if it moves from side to side. I don't think it is this as I ran more diags last night and am getting firing signals from PCM to coils and spark plugs are firing. Compression test also showed compression good but leak check showed otherwise. I am afraid that I have an issue with valves which would be better than rings at least.

As for the wiring possibilities, before I got the tools seen in pics below, I took off the fender flare and the inner fender to trace wires. I didn't find any issues but did identify where the possible issues could be, there is a prong that sticks out from firewall towards the lower part of the head on passenger side which I could see might cause rubbing through the wiring loom, luckily I have no issues there. I also found where the wiring loom goes up immediately behind the head/exhaust and can get very hot if the aluminum wrap was to fail, luckily no issues here either but I will be wrapping them all again while its in the shop.

The S/C was installed by Hennessey back in 2013 and I would hope that it hasn't been running bad ever since. But it is obvious that the previous owner (I am the 3rd owner) had it tuned by some folks that weren't up to speed and now I am dealing with those issues. At least I know who to stay away from but the guy I am dealing with is top notch and helping me out.

And I ended up getting some good test tools for future issues. Signal detectors, spark plug and coil testers.

I will let you all know what I find when I take the head off of it.

 

[CoronaRaptor]

Once you get it all figured out, rip that stupid decal off of the supercharge. Sorry, had to.

 

[randyb]

Well its been awhile since my last post. Change in jobs, addition of a grandbaby to the family and a few other things took me away from the forum.

So here is where we are now. Y'all aint gonna belive this. Engine pulled from truck, definately easier to remove with cab off like we do with diesel truck. 2 hours to pull cab beats fighting with the torque convertor bolts. Anyways, everything internal of engine was replaced because I figure that since I had it opened, I might as well. There honestly was no issues with anything other than a ring on piston 2. Cylinders all looked great and machinist was impressed by how they looked. Heads were removed and flow has been improved, valves and springs checked and replaced. All 8 coil packs replaced, all 16 plugs replaced, MAF sensor cleaned, supercharged oil changed, belt changed, power steering pump replaced. New battery Optima Red Top installed. No chagged wires found on the harness, no cracked wires found either. Reloaded tune to the truck.

Fired her up and within 10 seconds got the "P0352 Ignitiion Coil B Primary Control Circuit/Open" message. At this point the only thing we can figure out is the PCM has a bad driver on it for circuit 2 and either needs to be reprogrammed or a new PCM needs to be installed.

Thoughts?

 

[Old-Raptor-guy]

Need to check all the wiring and connections. PCM is very good at detecting open or shorted circuits and that is what it is telling you the issue is. In my experience PCMs are not real good and detecting problems inside themselves.

 

[Gen1TillDeath]

It’s interesting that the much higher misfire counts are on cylinders 2 & 4 and MUCH lower counts on 1 & 3. There was a member a few days ago having ALOT of misfires on all cylinders but it was only on 1 bank, think he said ended up being a clogged catilytic converter. Just something to think about.

 

[randyb]

Need to check all the wiring and connections. PCM is very good at detecting open or shorted circuits and that is what it is telling you the issue is. In my experience PCMs are not real good and detecting problems inside themselves.

in your experience would you be leaning towards replacing the PCM? I'm struggling to think that new Coils with wires would be the issue especially since the problem is only staying on Cylinder2.

 

[FordTechOne]

in your experience would you be leaning towards replacing the PCM? I'm struggling to think that new Coils with wires would be the issue especially since the problem is only staying on Cylinder2.

I would not. Old Raptor Guy is suggesting to check the wiring between the PCM and the affected coil. It’s much more likely that a wire or connector/terminal is damaged than the PCM has failed.

 

[Old-Raptor-guy]

I would not. Old Raptor Guy is suggesting to check the wiring between the PCM and the affected coil. It’s much more likely that a wire or connector/terminal is damaged than the PCM has failed.

Exactly and I assume you would agree. Why is it wiring/connectors always seem to be the forgotten red headed step child of vehicle repair?

 

[FordTechOne]

Exactly and I assume you would agree. Why is it wiring/connectors always seem to be the forgotten red headed step child of vehicle repair?

Yes, agree. I think a lot of times wiring/connectors are overlooked because they are not a “wearable” component, but heat, vibration, moisture, etc will induce any number of harness issues.

 

[Old-Raptor-guy]

Yes, agree. I think a lot of times wiring/connectors are overlooked because they are not a “wearable” component, but heat, vibration, moisture, etc will induce any number of harness issues.

just ask any Ford Contour owner. Showing my age again.