First off, I've been a 2 year lurker, never once posted, I've used these forums to fix a multitude of things on my 8 (fuel pump replacement, coils, plugs, starter, SSV cleaning, etc) but I've exhausted all my efforts at this point

Stats:
-04 greddy turbo with 102k miles, and an accessport.
Currently running 6lbs of boost.
-Just had the engine rebuilt 1k miles ago by speed1 in Allentown (with Goopy apex seals)
-coils replaced 2k miles ago, fuel pump 3k miles ago, starter 3k miles ago.
-BHR ignition kit, but not yet installed

My problem has been discussed before on a few threads, but nobody seems to come to a definite conclusion on any of them.

Problem:
Whenever I throw my car into neutral going about 45+mph, the engine doesnt even try to recover, it just dies. At lower speeds, it comes close to stalling, but catches itself before it does. It idles fine when it's just sitting, it accelerates fine, drives fine, but it always stalls when I put it into neutral at highway speeds.

Guesses:
A few guesses include, but arent limited to:
-MAF (i cleaned it multiple times, but maybe it's just old and broken)
-one of the vacuum solenoids (replaced SSV solenoid yesterday, so wouldn't be that one)
-something to do with the upstream o2 sensor maybe? (I usually only get 15mpg highway, which is pretty terrible)
-could it be the battery? (mine is somewhat old, but has a consisted 14v charge)
-not likely, but I have a remote starter (clutch doesn't need to be depressed to start car) and the clutch switch is disconnected
-I have no VFAD. The nipple behind the throttle body is capped


I replaced the ESS sensor, cleaned the SSV, checked for vacuum leaks, and replaced the neutral safety switch. I'm running out of options, and any help would be appreciated

 

Are you running the Greddy intake on the Compressor inlet? Can you post a picture of your engine bay? Any CEL?

 

Yeah I'm using the Greddy intake. Can't post a pic of the engine bay right now, I'm at work.

I should mention that the problem never used to happen. It just randomly started one day a few months before the engine replacement about a year ago( I've had it in storage all winter).

 

My first guess would be a boost leak or vacuum leak somewhere if it was running fine before. But assuming you have checked all the obvious things, I would get it smoke tested.

 

What's it got in it for a tune?

 

Not entirely sure about the tune. The dude I bought it from a couple years ago had a couple tunes loaded onto the acessport. I just know it pushes 6lbs of boost. Don't know how much hp, or afrs or anything. I plan on taking it to a dyno this summer. I do know that the guys at speed1 said it was a great tune. And my turbo is in impeccable shape

 

Check to see if the neutral switch is working properly.

Dos the engine hunt at idle? Between 750 and 1200rpm or so?

 

Be real easy on the engine. With a rebuild and major changes you could easily blow your engine if something was not done right.

What are your fuel trims. Both long and short term.

 

Yeah I mean a rebuild on the engine could essentially make the tune on it worthless. But we need more data. If you had a boost leak it would run like crap always. Knowing what you STFT at warm idle would tell us something but really some good data logs would help.

 

Alright. So I just got some new info today. Got a cel 2070 for ssv stuck open. I know for a fact that the ssv is clean and not gummed up. I'm pretty sure it's the impact switch that senses if the valve is closed or open. I also got a p0410 for secondary air Injection. My question is, could that switch being bad for the ssv cause my stalling issue? Even if the ssv isn't really stuck?

 

From the FSM:

Possible Causes:

SSV Stuck Open
SSV Control Malfunction
SSV Actuator Malfunction
SSV Solenoid Valve Malfunction
SSV Switch Malfunction
PCM Malfunction

 

Probably not......

 

Alright, update time:
I bought a used ssv on ebay for 55 bucks. Looked a little rough when it arrived, but after I cleaned it up I undertook the lengthy replacement process. After a few hours, everything is all back together. I started it up, and the idle seemed much smoother. I let it idle for about 15 minutes, and took it out for a test drive. I'm happy to say it didn't stall once. It came close a couple times, but I'm thinking since I had the battery disconnected, it needs to relearn the fuel trims. Needless to say, I'm pretty happy with the results. Thanks for all the help. I'll update after a few drive cycles, to make sure it really is fixed for good.

 

Yeah, nevermind, the problem is still there. It's driving me absolutely crazy. Ive tried everything. Smoke testing to look for vacuum leaks, new clutch switch, new neutral safety switch, new ssv and solenoid, new fuel pump (dw300), new baro sensor, new maf, new ess sensor, I'm running out of ideas, and it is driving me completely insane. I have also developed a hiccup at 8krpms that only happens on WOT, but won't happen if I gradually rev up to redline.

Maybe the VDI solenoid?
but wouldn't that throw a CEL?
and I dont think that would cause the stalling problems