Missing misfire counters and fuel trims always 0

I have a 2007 Dodge Caliber R/T race car that I've supercharged and campaign in the 24 Hours of Lemons racing series. The car was tuned with HP Tuners and up until last week was running quite well.

The car developed a serious misfire that we cannot track down. We were getting some crank sensor codes, but those have gone away. We now just get cylinder 1 misfire code and no other codes. We've swapped injectors, coils, plugs, etc. Our next step is to check fuel pump pressure and look for a vacuum leak.

During troubleshooting, I discovered that the fuel trims are always 0 and that I cannot find the misfire counters. I'm not sure if the car always had 0 fuel trims and no misfire counters, or if it was a side effect of the engine tune, or a recent development? Does anyone else know what could cause this or how to fix it?

Thanks!!!

Attachment 145758

Here is a log and my engine tune.

Attachment 145759

Attachment 145760

You have an O2 sensor code. Might be why it won't go into closed loop.

I don't have an answer for your misfire counters. do you know how to add a channel? They won't automatically show up in your channel, or pid list. You have to add them.

As for the misfire on cylinder 1, you need to do a compression and leak down test. Because it's supercharged it's more likely to hurt a piston.

Quote:

---

Originally Posted by edcmat-l1

You have an O2 sensor code. Might be why it won't go into closed loop.

I don't have an answer for your misfire counters. do you know how to add a channel? They won't automatically show up in your channel, or pid list. You have to add them.

As for the misfire on cylinder 1, you need to do a compression and leak down test. Because it's supercharged it's more likely to hurt a piston.

---

We've had the downstream CAT 02 sensor disconnected for a few years with no issues (there is no cat).

In the next few days we will inspect all engine harness connectors, check fuel pressure, compression, look for vacuum leaks and look at the waveforms on the coils, injectors and sensors with an oscilloscope.

How do I add a channel?

right click : )

Quote:

---

Originally Posted by LilSick

right click : )

---

Ok, I see that and did that. There were no misfire counters in the list.

It only had a "Monitor Status: Misfire (SAE)" but when I added that it displayed "Not Enabled"

How do I enable it?

Again, I'm pretty sure my car should have misfire counters because I've seen it on other Dodge Calibers.

I thought you had Sean Church tune that car?

Quote:

---

Originally Posted by ErrorMargin

The car was tuned with HP Tuners and up until last week was running quite well.

The car developed a serious misfire that we cannot track down.

---

It turned out to be a bad ECU....

Here are the symptoms I had:

P0300 Random Misfire
P0301 Cylinder 1 Misfire
P0304 Cylinder 4 Misfire
Rough running
Very low power
Flashing check engine light
Using my Autel OBD scanner, the computer was showing 31.54 inHg at idle (obviously implausible), but my analog vacuum/boost gauge showed 14 inHg

Here is what I tried to find the issue:

Swapped coils
Swapped spark plugs
Swapped injectors
Swapped MAP sensor
Swapped crank sensor
Looked for vacuum leaks
Checked engine bay ground points
Compression Test (185 to 191 psi on all cylinders)
Tested coil and injector harnesses for continuity to ECU, no cross talk, etc.
Fuel pump pressure test (58 PSI, this is in spec)
Visually inspected engine harness and all connectors for damage and corrosion
Thoroughly cleaned all engine harness connectors with electrical contact cleaner

None of that worked.

We did not know what else to try, so we bought a remanufactured ECU from ARES Technologies. I put the ECU in the car, flashed it with our tune using HP Tuners and it solved the problem.

I drove the car for an hour yesterday. It ran great and no CEL! Just in time too...I race at Thunderhill in a few weeks.

Still no misfire tables. I am open to suggestions on how to enable them.

Quote:

---

Originally Posted by LilSick

I thought you had Sean Church tune that car?

---

Yes, he did. I have over 15 hours on the track with his tune in the car and could not be more satisfied.

He did a great job, the car runs strong and does not overheat.

I highly recommend Shawn Church.

Attachment 146085