I just purchased brand new OEM wires a couple weeks back... you think those could be faulty?

 

How noticeable is the stock boost cut? I've never really noticed it hitting at 5k... is it possible that the ECU is expecting a boost cut, and is going wacky because its not happening for some reason?

Also, I have no idea regarding Accel enrichment...

 

Update:

I put in a new fuel pump (Evo IX pump) and it had no effect. I also ran two fuel cleaners through the system, and ran a bottle of octane booster with no change in behavior.

I purchased a fuel pump install kit (with a new fuel filter) and plan on putting that on as soon as I'm through this tank of gas. We'll see. I also purchased the MachV boost leak tester kit, and I'll see what the deal is.

The plugs look like their definitively running lean at high RPMs, but rich at idle. I can't image a boost leak would cause this, but I've read that air can leak in through the injectors if their not seated right... so who knows.

I'll keep you posted.

 

Keep us posted. Mine has a similar problem. I'm running a Mellon tune, TBE, and boost controller.

When I have my boost controller set to low (12lbs) the car accelerates very smoothly, and when its set on hi(21lbs) it misfires like whoa.

 

Will do. I've been going nuts trying to figure this out...


Based on what I've been researching and reading, it sounds like yours may be related to the boost "blowing out spark." Have you tried running a smaller gap (like .22) on your plugs, or going with something colder?



Also, I freaking love your signature. LOL @ Overnight Parts from Japan. Perhaps $15,000, or more.

 

I have to ask do you have a boost gauge? and if you do do you know if the vacuum line is good to the boost gauge? PM i have something that you may want to try.

 

To my knowledge he doesn't have a boost gauge, but his load calc seems to be fine.

If it was an injector it should only be effecting 1 cylinder. Thus one plug would be different then the rest.

If you want any help dude, just send me a PM I should be free all weekend.

 

LoRo: I don't have a boost gauge. I have a set of gauges on order; maybe they'll shed some light on the situation. Although, I do know the guy who owned it before me definitely had a boost gauge, and it was hooked up to a vacume line. The T is capped on end, and has lines running out of the other two... should I replace it all? I'll shoot you a PM as well.



I replaced the fuel filter, and although the old one was dirty, the new one didn't change anything. Still sputtering at 6500+ rpms...

Additionally, I hooked up the MachV boost leak tester to the turbo inlet and tried pressurizing the system, but it seems like the tester itself is leaking air, because I can't get it to hold any pressure at all. I'm going to pick up a vat of sealer and try again later in the week. Again, I'm still unsure how it could be a boost leak, since that would cause it to run rich -- right?

Another potential thing I haven't checked is the fuel pressure at the rail... maybe the fuel pressure regulator is fubar'd.


Could it possibly be electric? Is it possible that a loose or bad ground wire would cause this?



Markley: Thanks man. I'll be in and out of family functions all weekend; but hit me up any time your bored and want to do surgery on the Evo with me.

 

Check the FPR vac lines.

Check for SES codes.

Check EGR vacuum lines.

 

I've used Evoscan to check for DTC's, but nothing shows up and I don't have a SES light either. Is there a more efficient way to check for this?


LoRo recommended the FPR vac line. If there's more than one, I'll look into replacing them all. I've done a spot check several times, and don't see any loose lines -- but maybe one has a tear.

Where can I find the EGR vac lines?

Thanks for the advice.

 

Evoscan does not check DTC's.

 

EGR lines are behind the intake manifold. There are 2 nipples on it where vacuum lines attach. If you can feel the nipples and the lines are not there, you have to feel around for them and re-attach.

That is enough nipple feeling advice for now.

 

You can download scantech to check DTC's from aktivematrix.com. You have to register first.

http://www.aktivematrix.com/forum/dl...gory&cat_id=13

 

I did a boost leak test tonight, and can hear very faint leaking from the throttle body. It seems to be leaking where the armature (that holds the throttle cable) meets the TB, not where the TB meets the manifold. I can make the leak stop by applying pressure to the armature, pushing it towards the TB (in towards the firewall).

I have no idea if this would be causing the kind of behavior I'm seeing from the car at high RPMs... also, I'm really not sure why a boost leak would cause me to run lean.

I just downloaded scantech and am going to hook in now. I'll let you know if anything comes up.

 

... I just hooked up ScanTech. Definitely *not* the most intuitive software application I've used.

After some time, I finally got it to connect. I tried pulled the trouble codes using "Freeze Frame" but nothing was showing except P0000 (FF) which isn't anywhere on the list. I took the car out for a quick run, got it to sputter at high RPMs, no codes showed up, so I tried using Freeze Frame and got the same garbage.

Either I'm doing something wrong, or there aren't any codes.