Hesitation under 2 grand, smoking, rough start, SOHC woes...

[lofapoo]

Yes, I've searched. Yes, I'm still searching.

So I have a SOHC KA with around 150k that's been playing games with me recently, it's gotten pretty damn consistant now and I'm sure something big and bad is gonna happen soon.

First of all the car has trouble starting sometimes. It'll start, idle for a few seconds, then die. Or it won't start unless I pump the gas. But once she's running, she's running.

If I'm too soft on the pedal, she'll stumble under 500 RPMs and die every now and then. If I kick the accelerator just a bit the RPMs will drop a few hundred under idle then go on as normal.

When starting from a stop the pedal can be to the floor and it will stumble and go nowhere until the RPMs slowly reach 2 grand then she will put on as normal. NOT cool when you're trying to get out of someone's way.

I've also noticed some whitish grey smoke coming out of the exhaust every now and then when under load or at WOT.

Also there's clearly a vacuum leak somewhere. Whenever I'm on the throttle you can hear air being pulled until I let go of the gas. Also, when winding down into low RPMs (1.5k and below) you can hear it whistling, almost like a turbo :P This has been going on for some time now but it was fine until recently where it's just been running like dog**** all around.

Oh yeah, my gas milage blows, too.

ECU throws no codes.

It's an auto if that makes any difference. Also, no exhaust manifold heat sheild for a few thousand miles now, but the ECU doesn't throw any codes so I'm not sure it's affecting the o2 sensor.

I have a complete spare motor I can pull parts off of. I was considering swapping the MAF, fuel rail, and o2 sensor. I still need to check and replace the plugs but the plug wires are recent. Aside from that I'm at a total loss.

I'm sure this is a fuel related issue but let's face the facts this is the first fuel injected car I've ever torn into and I'm still pretty new so I have no idea where to look. It could be faulty injectors or o2 sensor or maybe TPS sensor? Will try sea foaming it to see if it'll clear the lines up a bit.

While I'm tearing into the search button, and my car, and pulling my hair out, perhaps someone can toss me some advice? Thanks in advance. I've got beer money in a paypal account ready to go out to the dedicated. Don't you dare think I'm kidding, either.

[lofapoo]

Here's a vid to give you a sample of what I get to deal with

http://www.youtube.com/watch?v=wM-5UACodJo

Yes, note the sweet live commentary.

[WWJD]

try pinching you fuel press. reg. line with vice. grips and if it starts up fine that could be your culprate. I've heard AIV could cause this as well. when you do the sea foam you'll be able to find the vac. leak(s) the smoke will come outta there

[lofapoo]

Good call on the sea foam for the vacuum leak(s)

Anyway I got a can of STP Fuel Injector Cleaner (yeah I know, bad idea) and it still ran like **** for a while. Now she runs like a top again, so it must have just been a clogged/dirty injector. Unless the problem decides to come back in a few days :P