legacycentral bbs

so I'm having some very intermittent power loss/ laggy under boost. It doesnt seem to matter what temperature it is outside, or if the engines hot or cold, its just a dog sometimes. lack of power, floor it and count to three before it decides it wants to get aup and go. or its running perfectly , makes boost quick and rips. its an ej22t swapped na car, vf39, 255lph pump, jecs green label maf ( i have swapped in another used one, but I have no idea if it is good or bad, both have been oil soaked from mt ej22e broken ringland. ) i have a new maf, but its pricey, and non returnable once used. any suggestions on troubleshooting?

If the maf is oil soaked, get some MAF cleaner from your local auto parts store and follow the instructions on the can. I would start there since it seems you're not wanting to use the new maf so you can return it.

You'll have to reset the ecu after this.

Do you have any trouble codes?

hey, it has been cleaned with crc maf cleaner a few times, ecu reset, longterm fuel trim reset with it

Oh cool, well if they're clean then that should eliminate the maf. How about plugs and wires?

plugs are perfect, wires new

Was your 255 new when you installed it? What about the condition of the turbo, specifically the wastegate. Have you ever gotten codes about your boost control solenoid?

cj91legss wrote:Was your 255 new when you installed it? What about the condition of the turbo, specifically the wastegate. Have you ever gotten codes about your boost control solenoid?

yes brand new last fall, turbo is brand new within 1500km, no trouble codes. running @12psi it seems better than @20psi.

Are you running the stock non-turbo ECU? What additional engine management are you using to add fuel & reduce timing under boost?

Legacy777 wrote:Are you running the stock non-turbo ECU? What additional engine management are you using to add fuel & reduce timing under boost?

stock non turbo ecu and 500cc/m water/meth,variable rising rate holley fmu with bleed, no ping, no knock.

would a malfunctioning iac cause the same issues? was just thinking that, if its not closing it'll bleed boost, and run real rich? can I just add a one way valve between the iac and the fresh air intake?

What intake manifold are you using, 22t or the stock 22e??

The stock turbo legacy has a check valve to prevent boost from bleeding back through the IAC valve. The non-turbo does not and it would be more challenging to add one to the non-turbo setup.

Check out these pictures which show the check valve in the turbo manifold.

http://main.experiencetherave.com/subar ... efault.htm

Legacy777 wrote:The stock turbo legacy has a check valve to prevent boost from bleeding back through the IAC valve. The non-turbo does not and it would be more challenging to add one to the non-turbo setup.

Check out these pictures which show the check valve in the turbo manifold.

http://main.experiencetherave.com/subar ... efault.htm

running the ej22e manifold on the ej22 engine. I have a ej22t iac and the little one way valve . but its very different. the iac may work on the non turbo intake but not with the check valve.
will try this out tonight

would explain why it runs lean intermittently on boost, as the fmu signal line is off the intake as well.

The check valve HAS to be between the intake manifold and the IACV. I don't know that valve you pictured will work.

cj91legss wrote:The check valve HAS to be between the intake manifold and the IACV. I don't know that valve you pictured will work.

why would the check valve need to be between the iac and intake? I installed it between the iac and colds air intake. it has cured my boost bleed......but... when off boost I can hear the iac sucking , is it leaking vacuum off idle? is it supposed ti? I thought iac was in operation at idle only

The IAC is in operation all the time. Think about the plate in your throttle body, when you aren't pressing the gas the TB is closed 100% right? How is the air getting into your engine allowing it to run? The idle air controller!

Inside your IAC is a funky shaped half cylinder that rotates based off the ecu signal. It rotates in front of a hole allowing more or less air to get thru the hole between the IAC and intake manifold. On turbo cars there is a diaphragm and metal grated plate there. That's what Josh is referring to as the check valve.

I only said I think the check valve should be between the IAC and the intake manifold because that's how it's designed from the factory and also think Subaru designed it that way for a reason. I would imagine boost could mess up the IAC internally.

As far as hearing your check valve, I would imagine it's because your check valve has caused a bit of an air restriction. Most likely because of what's inside of it.

I hope the info helps.

Thanks for all that info. I switched to a different style valve of a ford air injection system. So far all is great. Problem gone. I have a few spare iac motors if boost kills it.

Thats good!!

Curious tho, what does your setup look like now?

cj91legss wrote:Thats good!!

Curious tho, what does your setup look like now?

i'll get a pic, its a little untidy, not terrible,i need to eliminate some extra hose, get rid of some eyesore bends and 90 degree's , all seems to be functioning quite well, no concerns at all other than cold piston slap. my tranny with modded valve body will be going back together hopefully this weekend, then plan a date to install it ( not looking forward to that)

Having the check valve before or after the IAC valve shouldn't make that big of a difference as long as the check valve you add doesn't add restriction into the IAC air intake.

cj91legss wrote:Thats good!!

Curious tho, what does your setup look like now?

Fuel pressure is good. Good under boost. But when condition occurs it leans out. What all controls injector pulse?

Injector pulse is going to be mainly controlled via engine load and RPM. So the signal coming from the MAF sensor is rather important.

replaced. all is good. had to lean out afr's after maf replacement , initial boost was overfueling , then it would pull fuel leaning it out.

So what was the problem, faulty part?

Legacy777 wrote:So what was the problem, faulty part?

So i thought.. still dont know. Sometimes it runs great snappy as all can be . Perfect afr in boost. Quick spool up. Then its a dog . Slow spool way lean. New maf and a ecm reset seemed to work great for a day. Could it be my extended intake and maf related? Filter is situated in the rf fenderwell maf in approx same location. Could A dirty o2 sensor cause it to pull fuel?? The last engine was going through massive amounts of oil near the end. My next steps in my mind are return the filter to the engine bay. And clean the o2 sensor (its rather new genuine subaru) i went through 2 ntks previous to turbocharging. All other sensors are new. If my stock wrx bov was bleeding boost would it cause lean? Maybe i should plug it temporarily. Frustrating after running so well.