I NEED Boost... Opinions puh-lease

[cali yaris]

EXCELLENT.

[Focus_Sh1ft]

So uh... I've got problems.

Seemingly out of nowhere last night, my engine started running like complete garbage. Here's the symptoms...

-Cold start, engine warms up fine until about 130C water temp.
-After that, AFR goes super lean, vacuum drops to 9 inHG, IGN goes negative, RPMs less than 500
-If I step on the gas, the AFR goes super rich
-During cruise, my AFRs fall into a more acceptable range
-I have no new codes. Just the usual P0031 from not having a front O2 sensor.
-FIC bypass makes no difference.
-Battery voltage is healthy with engine on and off
-Ran two different sets of plugs with varying gaps - nope.

All signs point to a vacuum leak, but I haven't been able to find one. I'll have an air compressor tomorrow for a more thorough check, but I'm not entirely convinced I'll find one...

Other thoughts:
-Bad gas (I've had a similar experience before, but not this severe)
-Stuck valve

Help guys

[Bluevitz-rs]

for one, at 130°C you're cooking the engine. Maybe you mean °F when around the cool light goes off?

You've tried resetting the ECU? also, do you have a way to add the front O2 sensor back in?

[Bluevitz-rs]

for one, at 130°C you're cooking the engine. Maybe you mean °F when around the cool light goes off?

You've tried resetting the ECU? also, do you have a way to add the front O2 sensor back in?

[Focus_Sh1ft]

Yeah, 130F, typo... Otherwise my block would be on its way to becoming a puddle of aluminum.

ECU has been reset. Front O2 sensor I would need to pick up, but I need one for inspection anyway...

If a vacuum leak doesn't turn up, I'll grab an O2 sensor, return to closed loop, and go from there. Wish me luck

[Focus_Sh1ft]

So I can't find any vacuum leaks. I checked the injectors too. Look clean and all cycle fine.

But uh.. I did find my OEM O2 sensor floating around in the engine bay lmao.

The result is the same. The only difference is you can see the afrs being adjusted back to stoich, but they continue to go either super lean or rich (if I touch the gas). Also, no codes. I might attempt to drive a bit to complete the drive cycle but I'm not crazy about that.

Gonna do a compression test shortly. Let me know if you think there's any abnormal engine noises (this was taken while the afrs were somewhat maintaining stoich).

http://youtu.be/cgtU-mSDaBk

[Bluevitz-rs]

OH!! did you check the MAF sensor? Weird things happen when they get dirty.

PS, clicked on the vid with my home theatre system on with the sub, sounds like I was standing there looking for myself LOL

[Focus_Sh1ft]

Yeah I was surprised at how awesome the sound was too . Usually most phone videos sound like a gargled bunch of crap.

I checked the MAF. Pins and IAT sensor looks clean. Only other thing I can think of is voltage checks.

BTW, here's a video of the engine being bogged down (rich). Probably irrelevant, but eh.

http://youtu.be/zQSgTpNFrpU

[Bluevitz-rs]

Ok, back to the O2 sensor, was it bolted in place just not hooked up, or hook up, just not in the exhaust?

[Focus_Sh1ft]

I took it out once I found out how bad leaving it downstream, unplugged, was. It appears to be working fine and the car is maintaining closed loop without a problem (but not stoich). I guess it's still possible that its faulty, but that still doesn't explain why I could run open loop for so long without problems.

[Bluevitz-rs]

maybe it got damaged? and is giving bad out of range readings, but not enough for a code.

[Focus_Sh1ft]

It's definitely possible, but still wouldn't explain the open loop situation. I was thinking the same with the back O2 sensor, but that's purely for emissions right?

It looks like I need to drive enough to complete a drive cycle....

EDIT: Compression - 195, 195, 205, 205
Side note: If stock is 213 and that's after 2 and a half years of boost... Well, 'nuff said.

[Focus_Sh1ft]

Ok, I'm completely out of ideas...

-Replaced the MAF - no
-Checked the throttle plate - fine
-Monitored O2 sensor voltage - within range
-PULLED the rear O2 - no change (apparently it doesn't affect af/r at all, even though the service manual makes it out to be a pretty big deal)
-No exhaust leaks

I'm noticing more so that during closed loop I can 'somewhat' maintain stoich, but as soon as I touch the gas everything goes to hell. Rich, engine bogs, doesn't recover at all.

Also, I did manage to throw a system too lean code, but... duh. Not sure how credible that is because I was screwing with MAF skews in the FIC...
HELP ME lol. I've never been so stumped by anything engine related

[Bluevitz-rs]

Are you still running the stock fuel system?

[Focus_Sh1ft]

Yes. The pump and regulator are the only things I haven't checked, mainly because I can't find a thorough way to do so.

[Bluevitz-rs]

What's the intake air temp reading?

[Focus_Sh1ft]

Completely fine. So is the coolant temp.

Is the regulator the thing on the fuel rail? I remember reading somewhere it was part of the pump assembly...

[Bluevitz-rs]

Yeah part of the pump. Almost seems ECU related. The way it runs fun in closed loop while cold then like crap when in open.