Go back to MAF based tuning.

Have you tried the stock fuel pressure regulator

 

Go back to MAF based tuning.

Have you tried the stock fuel pressure regulator

Hello XJman ..thanks for responding! I plan to go back to MAF tuning for sure. I haven't tried taking out the stumble mod fix yet! Could that be a potential source of the problem? I hadn't even thought of it.

 

i responded on the thread in iwsti website. XJ do you think the injectors are too big for his build @XJman . i dont have the knowledge base about sizing injectors to builds

 

Yeah, sorry for the double post, it didn't seem like iwsti was gonna let me post it but

Oversized injectors wouldn't be the issue. Lack of fuel would be, lean is mean. Too much air without enough fuel would be a problem. I'm no expert, but injectors run off a duty cycle, so a larger injector doesnt have to work as hard to provide enough fuel to the engine for it to run properly.

 

Unlikely injectors are too big, it can happen, but I doubt this is that case.

Yeah, let us know about that FPR.

 

I swapped the oem fpr back in the car this morning. Reset the ecu at my tuner, drove it for about 60 miles this morning while datalogging. No check engine lights came on(they normally would after 30 miles or so), got into some real boost for the first time in months, car pulled strong, peaked at about 19.3 psi. Shut the car off, restarted it a few times. Felt a little bit of a surge on startup when the idle would come down which is where the car would usually throw a cel shortly thereafter. Thankfully it didn't. Im still a little leery about the cel coming back on. But I think a major part/source of the problem has been eliminated. I can only describe the surge as a "stronger than normal pulsation". But maybe it's just my paranoia that hasn't settled yet. I'll drive around some more tonight and datalog. Hopefully I can get all the I/M sensors to a ready state with no hiccups. I think if I make it past that hurdle, I'll be in the clear for good.

 

Sweet. Check with your tuner I don't know if the fpr is something that needs calibration in the ecu

 

I just got back from driving around for close to an hour trying to gauge how happy the car was. Noticed some small pullback around 3k rpm. I shut the car off and on a few times and unfortunately the cel popped back on. p0000 and p0304. I do believe flipping back to the oem fpr made a difference. I just wonder if it's too little too late at this point. feedback knock never exceeded 1.4-2.8, dam was at 1. and the car didn't overboost. it just does this weird surge on startup and then shortly after throws the codes. Yet again, I am stuck wondering wtf.

 

if you are sure the aftermarket items are not the source, do you think your symptoms sound similar to a timing issue? like a single tooth jumped at some point? it would have taken a hard pull/launch around the time it all started.

 

I suppose the only other possibility would be the spark plugs. They could be faulty. The main symptom of the problem is the surging on startup. .Or it's tune related. But the car doesnt seem off on the timing. Driveability is smooth for the most part. Could it be something in tune?

 

Gentleman I did want to give you guys an update. I finally was able to get the car running properly. It was in fact, the BATTERY! Lol. Went to my local Autozone on Monday night, did a check in the parking lot, it was low voltage. Apparently it had enough to start the car but not enough to make it run properly. I dropped in an Odyssey that night, completed a drive cycle, drove some more the following day and yesterday. No check engine, no misfire. Clear of codes. Also something I should have noticed sooner, my hill start assist, tcs and abs light were intermittently on and off as well, which I believe is an indicator of low voltage as well. So, there is a God, and my car now works properly, Praise Jesus.

 

That doesn't make sense unless the alternator is bad.

The battery starts the car, the alternator keeps it running. You can remove the battery from a running vehicle and it'll not have any bearing on the vehicles operation besides trouble codes.

I wonder if there is a loose ground or something somewhere that got jostled good with the battery moving around.

 

alt helps over 2k rpm -- under that if the battery is dead electronics act funny

 

Just when I thought I was out, it pulls me back in. So the accessport is showing this but the cel isnt lit up on the dashboard. She’s been starting and working fine the past few days since I swapped the battery. when I fired her up to head home from work tonight, I felt a hard start. Checked the accessport and found an “easter egg”. I even did some aimless driving to see if the car would throw the code, it didn’t. I feel like Im close to a full cure, but something small in the car just isnt right .

 

Does the accessport showing active codes but the car now actually throwing a cel mean anything?

 

The AP should be reading active codes in the ECU. So it should be showing.

 

Hello Gents,

I just wanted to give you guys a final update on my car, and where it sits as of now. I appreciate all of your feedback, and being apart of the Subaru community. I just got my car back from my local shop after installing the complete IAG fuel kit with their newest v3 tgvs rails and lines, street series Aos, A1000 fpr, and a perrin 2.4 turbo inlet. The car runs perfect now. It's so obvious that the problem was within the fuel system. Going stage2+ without a full fuel system upgrade is not something I would recommend on 2018+ cars. Stage 2+ meaning intake plus downpipe. The car was just simply leaning out too much. Even though I had thrown in the 1050x injectors and aem fuel pump, the rails and lines were also a severe weak point. They look like they came out of a base Impreza. The small diameter lines and poor construction are no bueno imo. I'm just happy to be at Stage 3 and the car feels smooth and great!