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Just another misfire/rough idle thread...


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  • 4 weeks later...

I hope you get everything fixed. I had a similar issue a couple of years back: car stalling at idle just after warming up (esp with AC on!). Tried a few different things. I believe I ended up replacing one coil pack. And then, I switched from a "pro-tune" (which, honestly, seemed a bit unprofessional to me) to a TA e-tune, and after that's it's not been an issue.

 

Another thing I did while I had the problem: use FreeSSM (at first, with APv1 tune) and then romRaider/ecuTune (with the TA tune) to bump up idle rpm. With FreeSSM, it got reset whenever the battery was removed, and the rpm at idle was high enough to be a little annoying, but at least the car didn't stall anymore in the middle of traffic when stopping at a light, which was much MORE annoying/dangerous.

 

I'm sure by now you've got confirmation that cyl #2 is bad, and all that, but hey - if you're willing to try something simple to save a few $K...

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What you did with your tune sounds very similar to what I did, except I use BtSsm to monitor and RomRaider/EcuFlash to play with the ROM.

 

Rescaling my MAF table really helped, and bumping up the idle smoothed things out even more. My problem is still there, but at least it doesn't stall anymore.

 

The car is running well enough to tolerate, and if I didn't get a fat tax return this year I'd probably just put off the rebuild until the motor fails. But alas, I did get a fat return and the rebuild will be sooner rather than later.

 

Does anyone know if the case bolts are torque-to-yield? I haven't found a solid answer yet and I'd like to reuse my existing bolts if possible.

Edited by StkmltS
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Just a thought, if the car is not running correctly but you made some changes to the tables to get it to run...ok, but you still haven't fixed the root cause.

 

I'm lead to believe these ECU's learn as you drive. Is your ECU learning bad things that may pop up later ?

 

 

I would want the engine running correctly (Map/tune wise) before I pulled it for a rebuild, than have issues trying to start it or shortly after the new engine is running.

 

Just thinking out loud here...

305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD).  CHECK your oil, these cars use it.

 

Engine Build - Click Here

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Just a thought, if the car is not running correctly but you made some changes to the tables to get it to run...ok, but you still haven't fixed the root cause.

 

I'm lead to believe these ECU's learn as you drive. Is your ECU learning bad things that may pop up later ?

 

 

I would want the engine running correctly (Map/tune wise) before I pulled it for a rebuild, than have issues trying to start it or shortly after the new engine is running.

 

Just thinking out loud here...

 

Thinking out loud is a good thing in my book.

 

I first noticed my problem when my idle became funky and the ECU would throw misfire codes like candy at a parade. By logging and analyzing boatloads of data, I found that my misfire almost exclusively happens at low rpm/mph. I don't understand why/if speed effects it, but it seems like it does. Anyways...

 

I really like using cruise control, so resetting my ECU became almost a daily habit.

 

  • My learned fuel trim (LV) for the lowest range (g/s) was consistently way off.
  • Stalling seemed most likely to happen immediately after an ECU reset.

Bingo! Resetting my ECU reset the LVs back to zero, which made it hard for the engine to breath properly, which caused stalling. Stalling became less frequent if I reset the ECU less frequently. I disabled the misfire codes in my ROM and my LVs stayed consistent because no more ECU resets, and stalling all but went away.

 

 

 

After cleaning my MAF sensor I started playing around with the MAF scaling table. It helped, alot. The misfire is obviously still present, but the LVs look good (within ± 5%). I also bumped up the idle RPM to smooth things out even more.

 

 

In conclusion:

Something is causing my car to misfire, something is causing my car to stall, and something is causing my fuel trims (with the stock MAF scaling table) to be way off. I'm assuming the same root cause for all three symptoms, and I'm assuming that root cause is the cracked piston.

Other than what I've already mentioned, my tune is stock. One of the tasks in my rebuild project will be to reflash the bone-stock ROM back into the ECU.

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  • 3 weeks later...

The camera diameter on that one looks a decent amount smaller than the one I have. The mirror attachment looks way more useful too. For less than $8 it's worth a shot. Unless you'll use it for something else that's 5m away, get the 2m length. Mine is 5m and dealing with all of the extra length is annoying.

 

Mine is [ame=http://smile.amazon.com/CrazyFire-2-0MP-Inspection-Camera-Locator/dp/B00EQNCMTY?ie=UTF8&keywords=borescope&qid=1463671560&ref_=sr_1_10&s=instant-video&sr=8-10]this.[/ame] It's branded as "CrazyFire" but the 'guts' are probably 99% the same as most others out there.

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The LEDs are adjustable (0-100%) so if glare was too much I just turned it down. 6 fully-lit LEDs were waaaaay more than enough inside the dark cylinder, and I think 4 LEDs would still be more than you need.

 

Creeping around under the intake manifold I usually don't even have the LEDs on.

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  • 2 weeks later...

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