Misfire after Unitronic Stage 2 IS20

[jeffdemara]

I'm just gonna say. You should not need to mix ethanol in to the tank to get rid of misfires or excessive knock in a OTS tune. This is crazy.

@jeffdemara
The lean area after the shift could be because the ECU is not reverting to the full load table after the shift. My car exhibits this problem also, but I just tune around it by making the the last row in my part throttle fuel table match what I want a full load.

What are you using to log and display the log?

Uniconnect+ cable and their logging software

 

[ZuMBLe]

Uniconnect+ cable and their logging software

Kudos to Uni for giving you what looks like proper logging ability!

 

[jeffdemara]

Haven‘t heard back from Uni yet. They are supposed to look at my logs...

But in the mean time, going today to pick up some RS3 coils. Will be interesting to see if that’s all this is, or if it’s just something with the tune. Will keep everyone posted either way though.

 

[Mk7tsi3door]

I’d try the decreased plug gap too! I remember someone posting about a sport wagon in another thread going though misfires on unitronic tune and that’s what helped them, I don’t remember what gap it was though, maybe when the guy from page 2 replies you can try that!

 

[jeffdemara]

Unitronic is basically saying because my turbo inlet elbow and intake are stock, it’s causing the wastegate duty cycle to go way too high during a shift, and causes a misfire (based on what they see on the log anyway).

Has anyone else done Stage 2 IS20 with Unitronic and encountered no issues while using the stock airbox and turbo elbow?

 

[TwinDad]

Unitronic is basically saying because my turbo inlet elbow and intake are stock, it’s causing the wastegate duty cycle to go way too high during a shift, and causes a misfire (based on what they see on the log anyway).

Has anyone else done Stage 2 IS20 with Unitronic and encountered no issues while using the stock airbox and turbo elbow?

That's a bunch of horseshit. Do you have a modified stock airbox?

 

[jeffdemara]

That's a bunch of horseshit. Do you have a modified stock airbox?

Grate has been removed. But still on stock filter as I read so much contraversy on drop in filters or even full intakes not really making any difference in performance (just sound).

 

[ZuMBLe]

Unitronic is basically saying because my turbo inlet elbow and intake are stock, it’s causing the wastegate duty cycle to go way too high during a shift, and causes a misfire (based on what they see on the log anyway).

Has anyone else done Stage 2 IS20 with Unitronic and encountered no issues while using the stock airbox and turbo elbow?

They said what?!?!! *throws everything off the table* WHAT?? They didn't tell you that you were low on boost fluid?

Can you post the log file?

 

[victorofhavoc]

I had misfire issues on a uni tune when using the rs7 plugs. Called them up and they kept repeating "stock plugs, stock gap". Coils likely won't be your issue.

I've also had a lot of misfires from blow by in track use, and those resulted in cylinder shutdown. Not saying that's exactly what you're dealing with, but oil surge can definitely be an issue if something isn't properly tightened down around the oil lines to the turbo or gaskets. If oil gets in and blows at your plugs, the misfires come up. In track use, it's the g force overwhelming the pcv valve when oil floods forward into the pickup.

I would ensure you're running correct plugs/gap first and then focus on your other changes (turbo), like someone else mentioned.

 

[jeffdemara]

They said what?!?!! *throws everything off the table* WHAT?? They didn't tell you that you were low on boost fluid?

Can you post the log file?

Not with Unitronic’s log files. They‘re encrypted and I can’t save them as a file to post. All I can do is include a screen shot..

 

[ZuMBLe]

The only time I've had misfire issues was when I was boosting it on ethanol with the fuel light on.

 

[jeffdemara]

I had misfire issues on a uni tune when using the rs7 plugs. Called them up and they kept repeating "stock plugs, stock gap". Coils likely won't be your issue.

I've also had a lot of misfires from blow by in track use, and those resulted in cylinder shutdown. Not saying that's exactly what you're dealing with, but oil surge can definitely be an issue if something isn't properly tightened down around the oil lines to the turbo or gaskets. If oil gets in and blows at your plugs, the misfires come up. In track use, it's the g force overwhelming the pcv valve when oil floods forward into the pickup.

I would ensure you're running correct plugs/gap first and then focus on your other changes (turbo), like someone else mentioned.

I just swapped to new OEM plugs gapped to .024”.

 

[victorofhavoc]

I just swapped to new OEM plugs gapped to .024”.

Perfect.

Also of note, and this almost throws a little credence to the statement you got from uni, I installed a p34 intake a while back and have been troubleshooting an intermittent misfire with crazy iat. I thought it was heatsoak and spent a lot of time working on airflow (which did help a ton), only to eventually find the p34 has been the culprit. I don't think it plays well at all with the uni tune, and I'm pretty sure the stock airbox performs better with their tune.

Why they'd point at the inlet elbow though, I'm really not sure. I had zero issues with the stock inlet elbow.

 

[ZuMBLe]

Not with Unitronic’s log files. They‘re encrypted and I can’t save them as a file to post. All I can do is include a screen shot..

Weird that your wastegate is shut at 20 psi to 4000 rpm - I wonder what the target is. Can you display the target pressure? Or torque request vs torque actual?

 

[jeffdemara]

Weird that your wastegate is shut at 20 psi to 4000 rpm - I wonder what the target is. Can you display the target pressure? Or torque request vs torque actual?