ZXT83

1. Im alittle confused by the by my diagram in my manuel
Now is the air regulator and coldstart valve one unit?
2. Would a fualty air regulator cause poor idle. I mean very poor idle. My z starts and runs for about 10 sec. then dies. Also if i push the throttle their is no throttle response what so ever. Plus, when the z dies i hear a smal " hiss" coming from what i believe to be the air regulator, I am lost for ideas here guys and i would greatly appreciate any input

NismoPick

The L28ET doesn't have a cold start valve, just an air regulator. And yes, it affects idle. You can pinch the hoses when running cold & listen for a change in idle.

Check for vacuum leaks, check the TPS, and check the AFM.

ZXT83

My tps is secure, but has a small chip in the corner, I pinched the lines on the air regulator and no difference in idle. Finaly the flap in the afm moves freely, how else can i check the afm? And i have no vacc leaks. Im just lost here

NismoPick

How do you know you don't have a vacuum leak?

As for the TPS & AFM:
-Disconnect the TPS & check both ends of the connection (plug & TPS prongs) for corrosion / moisture.
-The AFM check isn't testing the flap for movement... it wouldn't run at all if it didn't move. You need to check the connection & carbon track (inside the plastic cover). You can also tweak the AFM for better performance. Search on here, it's been fully covered.

Also... what's the timing set to?
And... check your CHTS connection.

ZXT83

Thank you nismo for the help, Im sure i have no vacc leaks only because ive replaced all rubber and triple checked all vacc connects. But im a newb so please excuse my dumbness

ZXT83

My tps plug and tps does have corrosion on it, which i will be cleaning off. However, i noticed that the tps plug only has two metal contacts on it and i assume it should have three considering the tps has three metal prongs, Bad tps plug?

snwbrderphat540

no, the turbo motors only have a 2 prong TPS setup, the 3 prong one is from a non turbo. but you can use that one just fine, no biggie.

ZXT83

Could i just use blake clean to clean up the corrosion on my tps and plug?

NismoPick

Brake cleaner removes oil, grease, and residue. Corrosion is none of those. The easiest way to clean the contacts is to dip them in Lime Away for a few minutes, wash them clean (light amount of water... like a spray bottle), blow dry, and apply some di-electric grease.

Do that to ALL your sensor and ecu connections & the car will definitely run better.

snwbrderphat540

agree with nismo but instead of washing them clean with a light amount of water, use a spray can of electrical connection cleaner, and for bad corrosion a take a pen knife (X-acto knife) with a SUUUUPER fine point to scrape on the insides

WildmaN

Also you can use Wd-40, and a toothbrush. A Z expert told me that a few years ago. And it does work. Anyway, any of these methods will get them clean. Good luck

ZXT83

Didnt want to start a new thread. Q: what is the purpose/operation of the bypass vavle on the intake mani?

NismoPick

Which bypass valve? There's a total of 4... since you weren't specific on which one:
#1: Air Regulator
#2: AAC Valve (the one on an angle)
#3: The stock recirc valve to release boost buildup when the TB snaps shut (lil check valve to the right of the AAC)
#4: The emergency release valve

Which are you talking about?

ZXT83

number 3, sorry, didnt relize

NismoPick

Yeah, it's a small blow off valve. Apparently it does the trick for a stock motor running stock boost. If you increase the boost level, I would suggest installing a good aftermarket blow off valve to release the extra pressure when you snap shut the throttle body.

skib

sorry gotta make a little correction on that one NismoPick.

the stock emergency release valve is not a blow off valve and shouldn't be mistaken for one. A BOV's job is to pop off the air thats about to head strait back into the turbo impellers after making boost. But the emergency release valve is just that, its job is to release all pressure at ~9lbs to prevent over boosting. You could be in the middle of a pull and if you hit 9lbs that things poping open and you loose all pressure.


and yes, you should add a nice BOV even now, your turbo will thank you in the long run.

NismoPick

^^^ Gotta correct you now....

I'm not talking about the emergency release valve. When did I say it was a BOV? I was talking about the small threaded port to the right (car right... not front to back right) of the AAC port. It's attached to the 5-way splitter on the back of the air regulator.

He indicated #3 on my list... #4 was the emergency release valve....

skib

hahahahaha

this facepalms for me



I thought hed picked #4


myyyyyyyyy baaaaaaad