[Interior Flaire]

I recently upgraded to a 20G, PE850s, APS inlet, and TGV deletes and had Clark Turner tune it but am having some problems.
After the install, I used a "safe" map for a week Clark sent me to get around with the daily driver. During the week, the car was dying off-throttle and I was getting misfire CELs. It was a real PITA to drive.
Clark stated during tuning that the car was misfiring at idle and that "my plugs were fouled". I am running one-step colder NGK Iridiums and they are pretty new. I also had Clark delete my O2 and TGV CELs during the tune.
Clark was not able to completely tune me because of boost creep issues and I now have an EWG in my garage ready to go on.
Anyway, I keep getting a CEL w/blinking cruise, checking it on my AP and it tells me the CEL is ?????. That's right, 5 question marks. I reset it, reload my RT map, the CEL goes away and then comes back. I believe the CEL occurs at idle. The car revs to cold start level when I first start it up then kind of studders a couple times and settles into normal idle. I can hear it popping out the tail pipe at idle and idle is kind of inconsistent and rough. I took the car to my buddy's shop yesterday to have him check the code and his high-dollar diag tool didn't even recognize that the car had a CEL even though it had one. Huh?
I bought new plugs today and replaced them and the old ones were FUBAR. The average gap was around .040+. The center electrodes were fried. WTF??? I mean these plugs were gone!
I started the car afterward and it did not studder as before and I am hoping the problem is gone. Will see tomorrow.
Has anyone had these types of issues after a tune/upgrade path? If the plugs were gone and causing a misfire, why wasn't the CEL a misfire CEL?
Why would the plugs be so fried? Any help is appreciated.

CB

[DigMaster-STi]

Well if he deleted you O2 CEL's, then thats probably whats popping up as ?????. He prob just deleted the code of O2, and not the actual CEL is that makes any sence. Also, maybe you should take the car to a better tuner. Sounds like nothing mechanical is wrong and just tunning issues need to be figured out.

[Interior Flaire]

That would mean that my O2 is bad and the system is just not displaying the code. I doubt that.

Update: I started the car this morning and it did its little studder couple times and settle in. I let it warm up, checked for a CEL...nothing. Cool! Went in the house, come out and here the popping sound out of the tailpipe. Look at the dash-CEL!
Checked it-same-????? Reset, reflashed RT map, and hauled ass to work.

The car is phenomenal on throttle. Once I get my EWG on and tuned, this thing is gonna be a monster.

Any help?

CB

[siusti]

I got that as well.. the ?????.. Mine was followed by misfire codes for cynliders 2 and 4.. Turns out we didn't have fuel going to them.

Otherwise.. I have no idea what the ????? means. I would suggest you check the connections to the plugs and ensure they are tight. I would also check all your fuel lines and ensure something isn't leaking.

[WXRTSI]

That happened recently to a friend of mine on his jetta. He had just installed a gt30 i believe, maybe a gt28r or something along those lines and we couldnt figure out why only cylinder 4 was loaded with missfires. Then, he noticed a fuel rail spacer was loose and the problem was solved. So, I would suggest chekcing the fuel rail and then all the coil packs and plugs.

[Interior Flaire]

Well, I REPLACED all the plugs and triple checked all coil packs and connections just last night. I will check the injectors/rails.

CB

[styyy]

Im getting the same ,stuttering,popping and stalling @ idle speed. I am waiting for Clark to come to NY in a month to tune my car,so hes supposed to send me a temp base map.

[Interior Flaire]

I think the problem lies in a) large injectors and the stock ECU b) allowing enough time (and WOT runs) for the ECU to completely learn a given setup.

CB

[ninjaboy76]

CB, are you still suffering from this problem? The ????? code is due to misfire. If your tuner removed the codes then they won't show up, but I guarantee that is what the code is. I had the same issue with my 04 STI with my SZ55 setup running the same PE850 injectors. I was tuned in Nov. 05 and not more than a month later I started having this problem once the cold weather set in. The reason I had this issue was because my first tuner set my idle to low with the larger injectors. This was causing the fuel to stumble and hence causing misfires. I had the car retuned in Jan of 06 by a different tuner that corrected the issues buy raising my idle from 750 to right around 950. If you haven't done so, I would have your tuner adjust your idle up and put the misfire codes back on. This should correct the issue.

[Interior Flaire]

No, I am not! Once I got the EWG hooked up with the AVC-R controlling it and did many, many WOT runs to redline while tuning the AVC-R, the ECU learned more and the CELs went away. At one time, idle was absolutely smooth until I changed batteries and the ECU lost its learning again. Argh!

So, with my experience with these large injectors, you have to thrash the crap out of the car to settle the ECU into a place where it is happy. The ECU with the AP just does not like large (PE850s) injectors.

Oh, another thing. The problem seems to be voltage dependent as well. I have an Unorthodox Racing underdrive pulley (came on the car) and the idle is affected more by the fans coming on, AC cycling, or anything else that makes the voltage dip. Seems PE850s like a stiff source.

CB